Volume 30,Issue 12,2014 Table of Contents

1 Mechanism of Inhibition by Polypeptide from Bay Scallop of H22 Hepatocarcinoma Transplanted into Mice

LIU Yuan , WANG Jian , MU Jian-lou , LIU Ya-qiong , SUN Jian-feng , WANG Jie

2014, 30(12):1-6.

[Abstract](1374) [HTML](0) [PDF 561.06 K](661)

Abstract:
The aim of this study was to explore the inhibitory effect and the underlying mechanism of inhibition by polypeptide from bay scallop (PBS) on H22 hepatocarcinoma transplanted in mice. A total of 50 Kunming (KM) mice were randomly divided into normal control group, H22 hepatocarcinoma model group, low-dose PBS (500 mg/kg?bw) group, medium-dose PBS (1000 mg/kg?bw) group, and high-dose PBS (1500 mg/kg?bw) group. An in vivo gavage experiment was performed. The results showed that the tumor inhibition rate in low-, medium-, and high-dose groups were 28.16%, 41.93%, and 84.00%, respectively, showing a dose-dependent effect. Compared to the model group, serum levels of mutant p53, survivin, 8-iso-prostaglandin F2α (PGF2α), and malondialdehyde (MDA) in the three PBS groups showed a decrease, while that of interleukin-2, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and tumor necrosis factor-α showed an increase. Additionally, the effect seen in the medium-dose group was more obvious than that in the other two groups. The same trend was found in the liver extracts from the three dose groups. Pathological evaluations also showed visible antitumor effects by PBS. Thus, this study indicated that PBS exerts obvious inhibitory effects on mouse H22 hepatocarcinoma cells.

2 Effect of Aloe-emodin on Learning and Memory Functions in Mice with Dementia

TAO Li , WANG Shi , XIE Jian-mei , WANG Yu-ting , DING Hong

2014, 30(12):7-10.

[Abstract](1162) [HTML](0) [PDF 558.55 K](660)

Abstract:
The aim of this study was to investigate the in vitro inhibitory activity of aloe-emodin on cholinesterase and the in vivo effect of aloe-emodin on cholinesterase activity in the brain, extent of spatial and object recognition, as well as learning and memory ability in a mouse model of Alzheimer's disease (AD). In vitro cholinesterase inhibitory activity was measured by the Ellman’s colorimetric method, while in vivo effect was assessed by using a mouse model of scopolamine-induced dysmnesia. Mice were randomly divided into four groups: normal group, model group, huperzine A positive-control group, and aloe-emodin group. The learning and memory ability was measured by using the Morris water-maze. The ameliorating effect due to aloe-emodin was measured by using behavioral experimentation (water-maze task) and brain cholinesterase activity as indicators. Aloe-emodin was found to effectively inhibit cholinesterase activity in vitro (IC50 = 18.37 μg/mL). Compared with the model group, aloe-emodin showed a significant decrease in escape latency, an increase in swimming time in the target quadrant, a reduction in brain cholinesterase activity, and an improvement in the learning and memory ability of the animal model. Thus, aloe-emodin was shown to ameliorate learning and memory deficit induced by scopolamine in mice, and the underlying mechanism may be related to inhibition of cholinesterase activity.

3 Antioxidant and Antitumor Activities of Curcumin

CHEN Jian-ping , LI Lin , SU Jian-yu

2014, 30(12):11-15.

[Abstract](1910) [HTML](0) [PDF 660.29 K](887)

Abstract:
In this paper, spectrophotometric method was employed to determine the ability of curcumin to scavenge 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and the oxidative hemolysis of erythrocytes induced by 2, 2′-azobis (2-amidinopropane) dihydrochloride (AAPH) was used to investigate the inhibitory effect of curcumin on AAPH-induced damage to human erythrocytes. The effect of curcumin on the viability of A375 malignant melanoma cells was measured by MTT assay, and the population of the apoptotic cells was detected by a flow cytometer. The effect of curcumin on the expression levels phosphorylated JNK and Akt was analyzed via Western blot assay. These results showed that curcumin exhibited strong scavenging effects on ABTS and DPPH free radicals in a dose- and time-dependent manner. Meanwhile, curcumin also effectively inhibited the AAPH-induced hemolysis of erythrocytes. The hemolysis inhibition rate of curcumin increased to 52.78 ± 1.03% at a concentration of 40 μM. The MTT assay showed that an increasing concentration of curcumin decreased the viability of A375 cells gradually. The cell viability after treatment with curcumin (40 μM) was only 21.50 ± 1.60%. Further flow cytometric studies showed that the SubG1 peak (apoptotic cells) increased in response to increasing curcumin concentrations. The SubG1 peak (apoptotic cells) reached 63.30% when the curcumin concentration was 40 μM. Further studies by Western blot assay demonstrated that the curcumin-induced apoptosis in A375 cells was related to upregulation of JNK phosphorylation and downregulation of Akt phosphorylation.

4 Immunomodulatory Activity of Glycosaminoglycans from Jinjiang Oyster Crassostrea rivularis

HU Xue-qiong , WU Hong-mian , FAN Xiu-ping , LIU Qian

2014, 30(12):16-24.

[Abstract](1455) [HTML](0) [PDF 882.80 K](678)

Abstract:
Glycosaminoglycans were extracted from the jinjiang oyster, Crassostrea rivularis, and their physicochemical properties and immunomodulatory activities were studied. Column chromatography was used to obtain a purified fraction of glycosaminoglycans, while high-performance liquid chromatography (HPLC) and infrared spectroscopy (IR) were used to study their physicochemical properties. An immunosuppressed animal model was established by injecting cyclophosphamide (CTX) in mice and the effects of Jinjiang oyster Crassostrea rivularis-derived glycosaminoglycans on the nonspecific immunity and humoral immunity of mice were studied. The activity of immune cells and natural killer (NK) cells was evaluated by the MTT assay. Tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-2 levels in mice were measured by enzyme-linked immunosorbent assay (ELISA). The level of nitric oxide (NO) was determined by Griess assay. The results showed that CGIa and CGIIa from the purified fraction of glycosaminoglycans consisted of uronic acid and glucosamine in a certain proportion, with relative molecular weights of 5.17 × 105 and 2.64 × 105 Da, respectively, in addition to sulfate groups. IR analysis showed that CGIa and CGIIa showed characteristic IR absorption profiles of glycosaminoglycans. The results of tests for glycosaminoglycans effects on the immune organ index, antibody production number, serum hemolysin level, cellular immunity, mononuclear macrophage, killing activity of NK cells in normal mice, were all positive, indicating that Jinjiang oyster Crassostrea rivularis glycosaminoglycans enhances immune function. CGIa and CGIIa also stimulated immune cells in normal mice to secrete cytokines including TNF-α, IFN-γ, IL-2, and NO. Enhanced immune function may be achieved by promoting the secretion of cytokines.

5 Antifatigue and Antioxidant Effects of Spiraea salicifolia L. Leaf Decoction in Mice

LIU Xiao-hui , LI Mu-ling , MO Yan , QUAN Wu-rong

2014, 30(12):25-29.

[Abstract](1121) [HTML](0) [PDF 614.07 K](768)

Abstract:
Antifatigue and antioxidant effects of Spiraea salicifolia L. leaf decoction in mice were investigated in this paper. Mice were randomly divided into different groups, and each group was administrated with different doses of .S. salicifolia L. leaf decoction by gavage; a blank control group was set up. The antifatigue effect of S. salicifolia L. leaf decoction was studied by the measurement of the weight-loaded swimming time, hepatic glycogen content, muscle glycogen content, serum urea nitrogen level, and lactate level in whole blood of mice; the levels of catalase and superoxide dismutase were measured in mice to study the antioxidant effect of the decoction. Compared with the blank control group, the changes of each indicator in mice administered low, medium, and high doses of S. salicifolia L. leaf decoction were as follows: the weight-loaded swimming time increased by 52.19%, 167.11%, and 197.37%, respectively; the hepatic glycogen content increased by 68.94%, 167.09%, and 195.81%, respectively; the muscle glycogen content increased by 3.28%, 19.67%, and 27.87%, respectively; the serum urea nitrogen level decreased by 14.89%, 19.54%, and 35.27%, respectively; the lactate level in whole blood decreased by 14.59%, 22.84%, and 33.21%, respectively; the catalase level increased by 15.48%, 25.40%, and 53.57%, respectively; the superoxide dismutase level increased by 19.59%, 26.31%, and 38.29%, respectively. Studies demonstrated that S. salicifolia L. had antifatigue and antioxidant effects; it could be used as a raw material for functional and healthy products and had certain development and utilization values.

6 Formation and Inhibition of Advanced Glycation End Products in Fried Dough Twist During Frying and Storage

LIU Hui-cui , LI Ju-xiu

2014, 30(12):30-36.

[Abstract](1271) [HTML](0) [PDF 717.31 K](868)

Abstract:
Fried foods are susceptible to Maillard reaction and lipid oxidation during processing and storage to form advanced glycation end products (AGEs), shown to be closely associated with several chronic diseases. In this study, changes in ?uorescent AGE and Nε-(carboxymethyl) lysine (CML) content in fried dough twist and the inhibitory effect of AGE inhibitors (quercetin, ferulic acid, and thiamin) on fluorescent AGE and CML formation during frying and storage were evaluated. The results suggested that the ?uorescent AGE and CML levels increased with increasing frying temperature and frying time. Fluorescent AGE and CML content in fried dough twist ranged from 258.34 to 1068.90 AU/g of food and from 1036.56 to 1603.72 mg/kg protein, respectively. High storage temperature and ambient oxygen showed a significant (p < 0.05) effect on the ?uorescent AGE level, while illumination had a limited impact. CML level increased significantly (p < 0.05) with increasing temperature and storage time, while oxygen and illumination showed no effect. AGE inhibitors (quercetin, ferulic acid, and thiamin) effectively inhibited the formation of ?uorescent AGE and CML, where the highest inhibition was observed with thiamin. Thus, the results from this study show that control of AGE formation is possible to some extent during frying and storage of fried dough twist, by altering conditions of these processes (frying time and temperature, storage conditions) and adding AGE inhibitors.

7 Structural Variations in the Subunits of Peanut Protein Isolates under Acidic Conditions

ZHAO Mou-ming , XIN Pei-xian , ZHAO Qiang-zhong , CHEN Nan-nan , CAI Meng-sen

2014, 30(12):37-42.

[Abstract](1106) [HTML](0) [PDF 518.47 K](912)

Abstract:
Structural variations in the subunits of peanut protein isolates under acidic conditions were investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), zeta potential, solubility, endogenous fluorescence spectroscopy, and particle size distribution analyses. The electrophoresis analysis indicated that when the pH value was <3.5, a portion of the subunits unfolded, a new 33 ku band was produced, and the intensity of the 18 ku band increased. The acid-hydrolysis of the subunits was affected by time and ionic strength. The peanut protein isolate subunits were subjected to acid-hydrolysis at pH 2.5 after 10 min at room temperature, and the amount of high molecular weight subunits decreased over time. When the ionic strength ranged from 0~0.1 mmol/L, there was a higher degree of acid-hydrolysis, which was inhibited when the ionic strength was above 0.2 mmol/L. Moreover, at pH values ranging from 2.0~2.5, the peanut protein isolate unfolded, interior groups were exposed, solubility was relatively high, and the maximum emission wavelength in the fluorescence spectra was red-shifted by 13.47 nm as compared to that under neutral conditions. When the pH was further decreased, the zeta potential was relatively low, peanut protein isolates formed high molecular weight soluble aggregates, and the maximum emission wavelength in the fluorescence spectra was blue-shifted to 335.27 nm.

8 A Mechanistic Study on the Interaction between DNA and Lucidin Using Madder Color

GAO Yan , LI Jun-sheng , WANG Qian-qian , LI Wei-lun , HUANG Guo-xia , YAN Liu-juan

2014, 30(12):43-47.

[Abstract](1045) [HTML](0) [PDF 533.84 K](717)

Abstract:
The mechanism of interaction between lucidin (Luc) and DNA at physiological pH of 7.41) was investigated by ultraviolet-visible spectrum and fluorescence spectroscopy, using ethidium bromide (EB) as a probe. The effect of Luc on thermal denaturation and viscosity of DNA was also evaluated. In addition, the interaction between Luc and DNA was explored in a potassium iodide (KI)-mediated fluorescence quenching experiment. Luc was also subjected to electrochemical characterization on a glass carbon electrode, by cyclic voltammetry. Based on the curve obtained by cyclic voltammetry analysis, and the effect of EB on the interaction between Luc and DNA, the interaction was proposed to be mediated via intercalation. The binding ratio of Luc-DNA was determined to be 2:1, and the apparent molar absorption coefficient (ε) was determined to be 8.12 × 104 L/(mol?cm). The presence of Luc increased the thermal denaturation temperature and viscosity of DNA molecules, attenuated the fluorescence quenching effect of KI, and resulted in the display of similar electrochemical properties as EB. Under the conditions used in the present study, Luc was observed to interact with DNA molecules via intercalation.

9 Influence of Stretching Temperature on the Physicochemical Properties of String Cheese Based on Principal Component Analysis

MIAO Ying , ZHANG Ai-lin , ZHAO Zheng

2014, 30(12):48-54.

[Abstract](1112) [HTML](0) [PDF 680.01 K](652)

Abstract:
String cheeses were prepared using a single-screw extruder, and principal component analysis (PCA) was used to investigate the influence of the stretching temperature on their physicochemical properties. The results showed that both cheese curd and string cheese stretched at 70 ℃ had a high expressible serum content; strong mobility in bound, occluded, and free waters; a high proportion of occluded and free water components; high L* and a* values; a low proportion of bound water component; and low hardness, gumminess, chewiness, and resilience. Compared with the cheeses prepared at other stretching temperatures, string cheese prepared at a stretching temperature of 90 ℃ had a lower expressible serum content; weaker mobility in bound, occluded, and free waters; lower proportions of occluded and free water components; lower L* and a* values; higher proportion of bound water component; and higher hardness, gumminess, chewiness, and resilience. The elasticity, b*, and c values of string cheese were not significantly influenced by the stretching temperature (p > 0.05). The comprehensive assessment model of the stretching temperature and physicochemical properties of string cheese was established based on the PCA. The principal component score indicated that good physicochemical properties of string cheese could be obtained at 80 ℃ with a screw speed of 45 r/min.

10 Inhibitory of α-Glucosidase by Polysaccharides from Cordyceps militaris

ZHU Zhen-yuan , LIU Xiao-cui , GUO Rong , ZHAO Liang , FANG Xiao-na , WANG Zhen-qian , ZHANG Jing

2014, 30(12):55-60.

[Abstract](1548) [HTML](0) [PDF 887.50 K](820)

Abstract:
In this study, the fruiting body of Cordyceps militaris was used to validate its α-glucosidase inhibitory activity in vitro. Using maltose as the reaction substrate and acarbose as a positive control, in vitro enzymatic reactions were carried out to validate the α-glucosidase inhibitory activity of polysaccharides (with different purities) from Cordyceps militaris, which were purified by water extraction, decolorization, alcohol precipitation, deproteinization, and column chromatography. The results of stepwise enzymatic reaction showed that the functional component with α-glucosidase inhibitory activity in Cordyceps militaris was polysaccharide, and the inhibitory rate gradually increased with increasing purity of the polysaccharide. The results of further enzymatic reactions using Cordyceps militaris polysaccharide purified by column chromatography showed that the rate of α- glucosidase inhibition increased with increasing concentration of polysaccharide, which was demonstrated that the inhibitory activity of Cordyceps militaris polysaccharide was dose-dependent within a certain concentration range. The half-maximal inhibitory concentration (IC50) value of purified polysaccharide was 4.22 mg/mL, showing a good hypoglycemic function. This study provides a theoretical basis for the future development of hypoglycemic drugs and health products using Cordyceps.

11 Microbial Community Diversity in Douchi from Yunnan Province Using High-throughput Sequencing Technology

LI Xiao-ran , LIU Xiao-feng , ZHANG Hai-yan , LUO Yi-yong , LIU Chen-jian

2014, 30(12):61-67.

[Abstract](1975) [HTML](0) [PDF 592.76 K](1006)

Abstract:
Douchi is a traditional fermented food with a unique flavor. Studying microbial diversity within douchi is important to improve the quality and food safety related to consumption of douchi. In this study, two kinds of douchi samples were collected from Jinghong (JH) and Menghai (MH) regions of Xishuangbanna Dai autonomous prefecture in the Yunnan Province. After DNA extraction, the bacterial 16S ribosomal DNA (rDNA) and fungal internal transcribed spacer (ITS) region were amplified and bar-coded pyrosequencing was carried out. The diversity of bacterial and fungal communities in the two samples was analyzed and compared based on the sequencing data. The results indicated that the predominant bacterium in the JH sample was Leuconostoc mesenteroides, followed by L. fallax. The most abundant bacterium in the MH sample was Staphylococcus gallinarum, followed by Tetragenococcus halophilus. The results for both samples showed a small number of sequences, which showed high similarity with those of salt-tolerant Candida etchellsii and bacteriocin-producing C. versatilis, both of which were the dominant fungi in both samples. In conclusion, the douchi from Xishuangbanna showed high microbial diversity and the predominant microorganisms were salt tolerant.

12 Screening and Identification of Broad-spectrum Antibiotic-producing Strain GX-21

YUAN Lin , WU Qing-ping , WU Ke-gang , ZHANG Ju-mei , MO Shu-ping , BAI Jian-ling

2014, 30(12):68-73.

[Abstract](1136) [HTML](0) [PDF 687.19 K](700)

Abstract:
A total of 1026 strains of actinomycetes were isolated from 156 soil samples collected from 11 locations in Guangdong Province and its surrounding areas. Soil was pretreated using enrichment culture method with calcium carbonate, and actinomycetes were isolated by plate dilution method. Gause No. 1 synthetic medium was used as the separation medium with 50 mg/L potassium dichromate as the inhibitor. Preliminary antibacterial screening using agar plug method, with five kinds of indicative bacteria including Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Candida albicans, and Aspergillus niger, and 95 active strains were identified. Re-screening consisted of two screening levels with eight kinds of indicative bacteria, including the five used in preliminary screening and Vibrio parahaemolyticus, Pseudomonas aeruginosa, and Proteus vulgaris. The agar plug method used in the first level provided 19 active strains, and the Oxford cup diffusion method in the second level finally provided eight optimal strains. The optimal strain GX-21 was identified as Streptomyces polychromogenes based on morphological and cultural characteristics, physiological and biochemical tests, and 16S rDNA sequence analysis. This strain showed broad-spectrum antimicrobial activity, effective against gram-positive and -negative bacteria and fungi.

13 Study on the Properties of an Inclusion Complex of Hydroxypropyl-β-cyclodextrin and Benzyl Isothiocyanates

LI Wen-zhao , DU Yi-deng , SHI Zong-yi , SHI Ying-zhou , RUAN Mei-juan , ZHU Hua-ping

2014, 30(12):74-78.

[Abstract](1245) [HTML](0) [PDF 732.80 K](660)

Abstract:
In order to increase the solubility and improve the heat stability of benzyl isothiocyanates, an inclusion complex of hydroxypropyl-β-cyclodextrin and benzyl isothiocyanates was prepared using hydroxypropyl-β-cyclodextrin and benzyl isothiocyanates as the host and guest, respectively. The phase solubility curve for hydroxypropyl-β-cyclodextrin-benzyl isothiocyanates was investigated, and the properties of the inclusion complex were studied using infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The phase solubility curve, which was found to be of the AL type, indicated that hydroxypropyl-β-cyclodextrin could significantly increase the solubility of benzyl isothiocyanates. The inclusion complex of hydroxypropyl-β-cyclodextrin and benzyl isothiocyanates formed with a 1:1 ratio had an inclusion constant of 408.8 L/mol. In the IR spectrum, the intensity of the characteristic absorption peak of benzyl isothiocyanates decreased, indicating that the –N=C=S group of benzyl isothiocyanate entered into the hydroxypropyl-β-cyclodextrin cavity. TGA results showed that the heat stability of benzyl isothiocyanates improved to some extent. SEM observations revealed that the inclusion complex consisted of irregular crystals. The inclusion of benzyl isothiocyanate increased its solubility, and expand the scope of its application. In addition, the heat stability of benzyl isothiocyanate also improved, which reduced heat loss during the process.

14 Physicochemical Characteristics and in vitro Antioxidant Activity of Polysaccharide PMP-2a from Pleurotus geesteranus

SUN Yu-jun , JIANG Chang-jun , ZHU Chang-wei , DAI Shi-hua

2014, 30(12):79-84.

[Abstract](1078) [HTML](0) [PDF 649.21 K](731)

Abstract:
In this study, a water-soluble, crude polysaccharide was extracted from Pleurotus geesteranus and the mycelium polysaccharide was obtained by deproteinization, discoloration, and purification using diethylaminoethanol (DEAE)-Sepharose Fast-Flow ion-exchange chromatography and Superdex-200 column chromatography. The purity of the polysaccharide was determined using high-performance liquid chromatography (HPLC); Colorimetric measurement of the total sugar, uronic acid and protein content; and physicochemical properties and partial structural characteristics, studied by ultraviolet (UV), infrared (IR) and β-elimination reaction methods. The in vitro antioxidant activity of PMP-2a was determined by superoxide radical and hydroxyl radical scavenging assays. The results showed that PMP-2a was a homogeneous polysaccharide, consisting of Rha, Glc, Gal, Man, and Ara in a molar ratio of 1:13.18:2.19:7.23:3.15. The total sugar, uronic acid, and protein content of PMP-2a were 82.6%, 19.8%, and 10.6%, respectively; no nucleic acid was found. Typical absorption bands of polysaccharides and glycosidic bonds in α-D-pyranoside were found in the IR spectrum. The molecular weight was 9.28 × 104 Da, and the β-elimination reaction indicated that PMP-2a was linked to peptide chains through an -O- bond. PMP-2a showed significant superoxide radical- and hydroxyl radical-scavenging activities in a dose-dependent manner.

15 Effects of the Degree of Substitution (DS) during Hydroxybutylation on the Physicochemical Characteristics of Maize Starch

ZHANG Ben-shan , YU Huan , WANG Jian-ping , QU Zhe-hui

2014, 30(12):85-91.

[Abstract](1234) [HTML](0) [PDF 740.37 K](649)

Abstract:
Hydroxybutylated maize starches with different degrees of substitution (DSs) were prepared using 1,2-epoxybutane, NaOH, and ethanol as the esterifying agent, catalyst, and dispersing agent, respectively. The microstructures of hydroxybutylated starch with different DSs were characterized by Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). A new absorption peak, ascribable to the hydroxybutyl group, was found at 1370 cm-1 in the IR spectrum of hydroxybutylated starch, confirming that hydroxybutyl groups were attached to native starch. XRD analysis revealed that hydroxybutylated starch still had an A-type X-ray diffraction pattern, confirming that the reaction mainly occurred in the amorphous region. Changes in the surface morphology of the starch granules before and after modification were observed via SEM, indicating that the reaction occurred on the surface of the starch granules. The result from the Brabender viscometer showed that the pasting temperature and set back values of the modified starches decreased significantly, whereas the peak viscosities increased. Moreover, these changes became more significant with increasing DS. When the DS reached a certain level, the hydroxybutylated starch was soluble in cold water. Thus, on increasing the DS, the transparency and freeze-thaw stability of the starch paste were substantially improved.

16 Antioxidant Activity of Lotus Leaf Fractions with Different Polarities and the Effect of Acid Hydrolysis on the Effective Fraction

JIANG Shen-hua , ZHOU Yong , XIAO Tong-fen , LIAO Liang , QU Wen-juan , WANG Ming-chun , DU Xian-feng , MA Hai-le

2014, 30(12):92-99.

[Abstract](918) [HTML](0) [PDF 603.86 K](774)

Abstract:
The aim of this study was to identify and further improve the antioxidant activity of the effective fraction in lotus leaves. Lotus leaf fractions were prepared by systematic solvent extraction, and antioxidant activity was measured to identify the effective antioxidant fraction, which was then hydrolyzed by using hydrochloric acid. The results showed that among all fractions with different polarities, the low-polar fraction (ethyl acetate fraction) showed the strongest antioxidant activity in terms of percentage of hydroxyl radicals and superoxide anions scavenged and total antioxidant capacity. Therefore, this fraction was identified as the effective antioxidant fraction of lotus leaf. The antioxidant capacity of the effective fraction was significantly improved by hydrochloric acid hydrolysis (P < 0.05 or P < 0.001). Compared with the effective fraction before hydrolysis, the total reducing power, percentage of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenged, ferric-reducing antioxidant power (FRAP, OD593), total antioxidant power (OD695nm), and percentage of hydroxyl radicals scavenged of the post-hydrolytic fraction showed an improvement by 48.5%, 58.22%, 64.3%, 22.15%, and 100.48%, respectively. The percentage of superoxide anion radicals scavenged showed an improvement from 42.43% ± 1.23% to 44.97% ± 0.22%. The results demonstrated that the active antioxidants of lotus leaf comprised of mainly low-polar compounds in the effective fraction (ethyl acetate fraction), and hydrochloric acid hydrolysis was an effective approach to improve the antioxidant capacity of this fraction. This study provides a basis for further research and development of functional foods by using lotus leaf.

17 Effects of Moisture Mobility on Qiuhong Plum during Storage

ZHU Dan-shi , LIANG Jie-yu , LV Jia-yu , TAO Zhen , FENG Xu-qiao , LI Jian-rong

2014, 30(12):100-105.

[Abstract](1319) [HTML](0) [PDF 548.39 K](1080)

Abstract:
Moisture mobility during fruit storage directly affected the storage quality of fruit and the moisture mobility regularity and mechanism in different storage temperature were distinct. To explore the effects of moisture mobility on the quality of plum, the moisture modility of Qiuhong plum in different temperature (0 ℃, 4 ℃, 10 ℃, 20 ℃) during storage was determined by low field nuclear magnetic resonance (NMR) technology and the microscopic process for the moisture dynamic variation was studied. Combined with texture analyzer, the skin hardness, pulp hardness and adhesiveness were determined and the correlation was analyzed. The results showed that in lower storage temperature, the moisture content, vacuoles water and texture quality of plum reduced more slowly. Compared with 10 ℃ and 20 ℃, stored in lower temperature, cell wall and cytoplasm water appeared special peak and nadir respectively, which maybe the key point to the effect of low temperature on plum quality. Cell wall water presented no significant correlation with the texture of plum (p>0.05); in lower storage temperature, cytoplasm water presented a significantly negative correlation with the skin hardness and pulp hardness (p<0.05), vacuoles water presented a significantly positive correlation with the skin hardness, pulp hardness and adhesiveness (p<0.05); both cytoplasm water and vacuoles water presented no significant correlation with pulp adhesiveness in 10 ℃ and 20 ℃ (p>0.05).

18 Study on the Effects of Chemical and Physical Refining Processes on the Deterioration in the Quality of Wheat Germ Oil

YANG Ying , LI Gui-hua , ZHAO Fang , WANG Xiang-yun

2014, 30(12):106-112.

[Abstract](1058) [HTML](0) [PDF 573.33 K](716)

Abstract:
In order to improve the quality of refined wheat germ oil, the degree of deterioration in the quality of wheat germ oil during chemical and physical refining was investigated. For the wheat germ oil processed by chemical refining, the acid value dropped to 0.18 KOH/(mg/g), the trans fatty acid content increased to 0.070% from an undetectable level in crude oil, and the tocopherol content decreased by 37.83%. For the physical refining of wheat gream oil, deacidification was conducted under a residual pressure of ≤60 Pa in a temperature range of 200~240 ℃ for 2~8 h. The acid value dropped to 5.49 KOH/(mg/g)~0.19 KOH/(mg/g), the trans fatty acid content was between 0.13% and 3.13%, the peroxide value ranged from 1.61 mmol/kg~4.33 mmol/kg, the anisidine value ranged from 13.76~59.3, and the tocopherol content decreased by 26.68%~85.90%. Comparison of the two refining processes revealed that the chemical refining process had less significant effects on the deterioration of wheat germ oil quality than the physical refining process, particularly in regard to preventing the increase in the trans fatty acid content, and the loss in vitamin E content among others. Therefore, chemical refining is suitable for functional and nutritious oils rich in unsaturated fatty acids, vitamin E, etc.

19 Comparing the Functional Properties of Sea Bass Collagen Peptides (SBCP) with Different Molecular Weights

ZHU Jing , LIU Lei , ZHANG Ming-wei , WEI Zhen-cheng , ZHANG Ye-hui , MA Yong-xuan , CHI Jian-wei

2014, 30(12):113-118.

[Abstract](1314) [HTML](0) [PDF 740.25 K](863)

Abstract:
In this study, sea bass collagen peptide (SBCP) solution was fractionated using ultrafiltration membranes with different molecular weight cutoffs (Mw COs). The enzymatic hydrolysis of collagen peptide extracted from sea bass processing byproducts yielded collagen peptide solution, which was separated into three components with different molecular weights (Mw s): SBCP1 (Mw < 2000 u), SBCP2 (2000 u < Mw <3 000 u), and SBCP3 (Mw > 3000 u). The water absorption capacity, water holding capacity, solubility, oil absorption, emulsifying properties, emulsion stability, foaming properties, and foaming stability of those components were also compared. SBCP1 showed the highest water absorption capacity and solubility; SBCP3 had the highest water holding capacity, emulsifying properties, emulsion stability, foaming properties, and foam stability; SBCP2 showed the highest capacity for oil absorption. This result suggested that there was a significant difference in physicochemical characteristics among components of SBCP with different Mw s and that the functional properties were closely related to the Mw distribution. This study provides guidance for the development and application of SBCP products.

20 Analysis of the Solid-state Fermentation Process in Zhenjiang Vinegar by Using Hyperspectral Imaging

ZHU Yao-di , ZOU Xiao-bo , SHI Ji-yong , ZHAO Jie-wen , XU Yi-wei , LIN Tian-zhong

2014, 30(12):119-125.

[Abstract](1402) [HTML](0) [PDF 734.38 K](834)

Abstract:
The objective of this study was to investigate the imaging and spectral characteristics of fermented vinegar grains by using the hyperspectral imaging technique (HPIT), to rapidly predict the fermentation status. Initially, a primary component analysis (PCA) was performed. The pre-treated spectral information was then combined with the partial least squares (PLS), interval PLS (iPLS), and synergy interval PLS (siPLS) of the full spectrum to establish rapid prediction models for total acid content, pH, and non-volatile acid content, in order to select the best prediction model. Three characteristic images were chosen based on the different main components represented by the imaging data. We extracted four characteristic variables (contrast, correlation, angular second moment, and homogeneity) by texture analysis, based on gray level co-occurrence matrix. The K-nearest neighbor (KNN) method was used to establish a recognition model for fermented vinegar grains, with a predicted recognition rate of 90.04%, which would enable a good prediction of the vinegar grain fermentation status. The synergy interval partial least squares (siPLS) model displayed the best performance, predicting the total acid content, pH value, and root mean squared error of prediction (RMSEP) of non-volatile acids to be 0.75, 0.05, and 0.3, respectively. This finding indicated that the model could rapidly predict important physical and chemical parameters. Therefore, it would be feasible to use HPIT for the rapid prediction of fermentation quality of vinegar grains. This study provides an effective and rapid means of detection to improve the process operation and quality of fermentation.

21 Ultrasound-assisted Synthesis of n-Butyl Furoate Catalyzed by PMo12/SnO2 and Its Mechanistic and Kinetic Studies

XIONG Li-zhi , WANG Jia-jian , TENG Yao , HE Ze-qiang

2014, 30(12):126-132.

[Abstract](1003) [HTML](0) [PDF 702.60 K](688)

Abstract:
SnO2-supported 12-molybdovanadophosphoric acid (PMo12/SnO2) was prepared by a simple impregnation method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). n-Butyl furoate was synthesized under ultrasound irradiation with PMo12/SnO2 as catalyst. Through single factor experiments, the effect of each factor on the yield of n-butyl furoate was investigated. The optimal reaction conditions were as follows: the molar ratio of butyl alcohol to furoic acid was 3:1; the amount of catalyst was 0.50 g; the volume of water-carrying agent was 5 mL; ultrasound irradiation time was 15 min; ultrasound irradiation power was 200 W. Under these conditions, the yield of n-butyl furoate reached 97.5%. Compared to other reported methods, this ultrasound-assisted synthesis of n-butyl furoate catalyzed by PMo12/SnO2 had advantages such as shorter reaction time, high yield, and low energy consumption. The kinetic parameters of the reaction at 343 K, 353 K, and 363 K were measured, and the results indicated that the ultrasound-assisted synthesis of n-butyl furoate catalyzed by PMo12/SnO2 followed second-order kinetics, with an apparent activation energy of 27.85 kJ/mol. Compared to simple ultrasound-assisted esterification, PMo12/SnO2-catalyzed esterification, and direct esterification in a hot water bath, the ultrasound-assisted synthesis catalyzed by PMo12/SnO2 significantly decreased the apparent activation energy of esterification, accelerated the catalytic reaction, and improved the yield of n-butyl furoate, owing to the potential synergistic effect between ultrasonic treatment and the catalytic action of PMo12/SnO2,.

22 Selection of a Mathematical Model for the Sol-gel Transition in Soy Protein Isolate/Dextran Mixtures

ZHU Jian-hua , LAI Fu-rao , YANG Xiao-quan , QI Jun-ru , QIN Mei-xin

2014, 30(12):133-137.

[Abstract](1140) [HTML](0) [PDF 697.67 K](609)

Abstract:
The characteristics of the luminance (L*) vs. gelation time (t) curves of glucono delta-lactone (GDL)-induced sol-gel transition in soy protein isolate (SPI)-dextran (DEXT) mixture were analyzed by tracking the luminance values. The results showed that the L*-t curves had an “S-shaped” pattern. Six different mathematical regression models were fitted to the L*-t curves, and the results were compared. Under sonication treatment at different intensities and after the addition of SPI-graft-DEXT (SPI-g-DEXT) conjugates, the Boltzmann function L* = L*2 + （L*1 - L*2）/（1 + exp（（t - tg）/dt）） was the best fitting model with the highest correlation coefficient R2, minimum residual sum of squares (RSS) between the actual and simulated values, strong adaptability, and explicit physical meanings that the corresponding model parameters had. Three areas with specific characteristics of the L*-t curves were explicitly designated using the Boltzmann function as follows: lower sol phase, sol/gel phases in coexistence, and upper gel phase. Based on the changes in dynamic luminance, a novel quantitative method for analyzing the initial gelation time, total gelation time, and gelation velocity of the GDL-induced sol-gel transition process in SPI/DEXT mixtures was proposed.

23 Synthesis of 2,3-dihydrobenzo[1,4]dioxin-6-ol and Its Antioxidant Activity in Oils

LUO Zhong-ming , LU Yu-yun , YAN Ri-an , SUN Yuan-kui , ZHOU Hua

2014, 30(12):138-142.

[Abstract](1136) [HTML](0) [PDF 489.37 K](808)

Abstract:
In this paper, the synthesis and antioxidant activity of 2,3-dihydrobenzo[1,4]dioxin-6-ol, a sesamol analogue, are described. Using catechol and 1,2-dichloroethane as starting materials, 1,4-benzodioxane was prepared by cyclization under refluxing basic conditions, and then, Friedel-Crafts acylation was carried out to yield 6-acetyl-1,4-benzodioxane. The final product was obtained after Baeyer-Villiger oxidation, hydrolytic acidification, and column chromatography. The concentration of NaOH solution in the cyclization, the solvent used in the acylation, and the oxidizing agent in the oxidation were optimized. The optimum conditions for each step were as follows: concentration of NaOH, 50%; solvent for the acylation reaction, nitrobenzene; oxidizing agent in the Baeyer-Villiger oxidation, 3-chloroperbenzoic acid. Structural identification and characterization were conducted using infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance spectroscopy (13C-NMR), and the final product was identified as 2,3-dihydro-benzo[1,4]dioxin-6-ol. The antioxidant activity of the obtained product in oils was evaluated, and the results showed that this sesamol analogue displayed antioxidant activity in both animal and vegetable oils.

24 Influence of Nisin Compound Antimicrobial Agent on Microbial Diversity and Quality of Stored Wheat

LI Ting-ting , CHEN Wei , LU Zhong-yi , LI Guang-fu

2014, 30(12):143-148.

[Abstract](1146) [HTML](0) [PDF 724.30 K](712)

Abstract:
Wheat grain was treated with an antimicrobial agent prepared from various combinations of potassium sorbate, 2-aminobutane, and nisin, and then stored at 30 ℃ and 75% relative humidity for 35 days. The effect of the antimicrobial agent on the microbial diversity in the stored wheat and its correlation with the subsequent quality of wheat was studied. The result showed that fungistatic activity of nisin, nisin in combination with potassium sorbate, nisin in combination with 2-aminobutane, potassium sorbate in combination with 2-aminobutane, and nisin in combination with potassium sorbate and 2-aminobutane was 3.62, 64.34, 8.61, 37.03, and 50.02 times higher than that of the control, respectively. Moreover, the values for inhibitory activity of nisin in combination with potassium sorbate and 2-aminobutane on the microbial count of fungi, Aspergillus, Penicillium, Bacillus sp., and other bacteria were 50.02, 55.44, 2.89, 75.14, and 86.66 times higher than that of the control. The optimal ratio of the combination was 0.20 g Nisin, 1.00 g potassium sorbate, and 2.00 g 2-aminobutane per kilogram of wheat. The correlation analysis showed that the microbial count of fungi, Aspergillus, Penicillium, Bacillus sp., and other bacteria were positively correlated with the amount of fatty acids and the total acids, and negatively correlated with the precipitation value.

25 Rapid Discrimination of Fresh and Stale Corn Using Raman Spectroscopy

HUANG Ya-wei , ZHANG Ling , WANG Ruo-lan

2014, 30(12):149-152.

[Abstract](1258) [HTML](0) [PDF 568.83 K](775)

Abstract:
Fresh and stale corn samples were distinguished using Raman spectroscopy coupled with discriminant analysis. A total of 75 corn samples of the Zhengdan 958 variety were collected in Henan Province. After grinding and sieving, the powdered samples were placed in special PVC bags. Raman spectra were directly measured through the sample bags using optical fiber; polynomial smoothing, baseline correction, and first derivative methods were conducted to process the raw spectra. The discrimination model was developed with principal component discriminant analysis coupled with Mahalanobis distance. The best result was achieved when nine principal components were used with a spectral range of 914~1369 cm-1. The correct classification rates in the calibration set and the prediction set were 92.7% and 90%, respectively. Subsequently, the partial least squares discriminant analysis method was used to develop the corresponding recognition model. The best result was achieved when the number of factors was seven and the full spectral range was used. The correct classification rates in the calibration set and the prediction set were 100% and 95%, respectively. The correct classification rates obtained from the partial least squares discriminant analysis method were higher, indicating that Raman spectroscopy could be used to discriminate between fresh and stale corn rapidly and showed great potential in the quality evaluation of stored grains.

26 Effect of Micronization on the Physicochemical Properties and in vivo Absorption of Gastrodia elata Bl. Powder

YANG Rui-li , CHEN Yun-wen , LIAO Zhen-yu , WANG Yu-qi , SUN Yuan-ming

2014, 30(12):153-157.

[Abstract](1276) [HTML](0) [PDF 667.84 K](774)

Abstract:
The purpose of this study was to investigate the effect of micronization on the physicochemical properties of Gastrodia elata Bl. powder and its absorption in rats. Physicochemical properties such as particle size, distribution, microstructure, angle of repose and slide, swelling capacity, bulk density, solubility, and components, were compared between powdered samples of fine and micronized Gastrodia elata Bl. The absolute bioavailability of gastrodin, the active component of Gastrodia elata Bl., was also determined. Results showed that micronization effectively reduced the average particle size from 121.50 to 34.09 μm, narrowed the range of particle size distribution, and resulted in a more uniform particle size. Compared to fine powder, micronized powder showed varying degrees of improvement in swelling capacity, bulk density, and solubility; however, the fluidity decreased. Infrared spectroscopy showed that the active components of Gastrodia elata Bl. powder were not affected by micronization. The absolute bioavailability of gastrodin in fine and micronized powders was 34.18% and 45.49%, respectively. The results showed that the micronization-induced improvement in physiochemical properties of Gastrodia elata Bl. powder could improve dissolution of nutrients and the subsequent absorption of the active component, gastrodin. Thus, this study provides a theoretical basis for the application of micronization in the production of Gastrodia elata Bl. powder.

27 Effect of Temperature and Relative Humidity on Absorption Characteristics and Kinetic Models of Different Absorbent

ZHAO Ya , SHI Qi-long , WANG Xiang-you , WANG Juan

2014, 30(12):158-163.

[Abstract](1162) [HTML](0) [PDF 955.31 K](1007)

Abstract:
The static adsorption method was employed to investigate the moisture absorption characteristics of seven different moisture absorbents, including calcium chloride (CaCl2), sodium hexametaphosphate, sorbitol, konjac glucomannan (KGM), chitosan, activated aluminum oxide powder, and bentonite, which were exposed to different temperatures (2 ℃, 10 ℃, and 18 ℃) and relative humidities (RHs) (76%, 86%, and 96%) for 15 days. The results showed that moisture absorption for the same absorbent increased with increasing RH at a fixed temperature, while moisture absorption varied for different absorbents with elevated temperature at a fixed RH. The Weibull model was used to fit the experimental moisture content data; the model parameters of M∞ and β were obtained, and the relationship between M∞ and temperature/humidity was established using linear regression analysis. Except for sorbitol, the accuracy of fit of the moisture content data to the Weibull model was high. The moisture absorbents with high holding capacities (M∞) were CaCl2 (1.117~2.137 g H2O/g), sodium hexametaphosphate (0.297~0.856 g H2O/g), and sorbitol (0.083~38.567 g H2O/g), with β ranges of 25.5~119.8 h, 91.2~290.0 h, and 1.1~185.6 h, respectively. The M∞ values of chitosan and bentonite were found to be dependent on temperature and RH, while those of sodium hexametaphosphate and sorbitol were only affected by RH. These results will provide a theoretical basis for RH control during modified atmosphere (MA) storage of Agaricus bisporus.

28 Effect of High Hydrostatic Pressure Treatment on the Quality of Pleurotus eryngii

YANG Hua , YU Xin-ru , QIAN De-kang , LIU Li-jun , QI Xiang-yang

2014, 30(12):164-169.

[Abstract](1242) [HTML](0) [PDF 585.14 K](708)

Abstract:
In this study, the effect of varying high-hydrostatic-pressure processing (HPP) conditions (pressure: 100, 150, 200, 250, and 300 MPa; holding time: 3, 6, 9, 12, 15, and 18 min) on the quality characteristics of fresh Pleurotus eryngii, such as polyphenol oxidase (PPO), weight loss, color, hardness, and sensory quality were studied. The results showed that with increasing pressure and holding time, the PPO enzyme activity and elasticity of the HPP-processed samples increased after an initial decline, the brightness (L*) value and hardness decreased gradually, while the yellowness (b*) value and rate of weight loss increased. During storage (0~12 days) at 4 ℃, PPO enzyme activity was lower, rate of weight loss was greater, and extent of changes in color and hardness were smaller in case of HHP-treated samples than those of untreated samples. The results thus indicated that the optimal pressure and holding time for HHP processing were 200 MPa and 9 min, respectively.

29 Effects of Three Drying Methods on the Quality of Jinhua Ham Slices

MENG Yue-cheng , ZHENG Bo-gen , CHEN Jie , LI Yan-hua , YUAN Jie , WU Qin

2014, 30(12):170-175.

[Abstract](1203) [HTML](0) [PDF 562.97 K](718)

Abstract:
The aim of this study was to investigate the effects of three drying different methods, namely hot air drying, freeze drying, and vacuum drying, on the quality of Jinhua ham slices. The color, hardness, volatile flavor substances, and rehydration characteristics as a function of drying method were analyzed. The drying method had a significant influence on the total color change (ΔE, P<0.05) of the Jinhua ham slices. Vacuum drying was much better than hot air drying and freeze drying. The hardness of dried Jinhua ham slices was less than that of fresh ham slices. Hot air drying caused the smallest reduction in hardness at 2397.12 g. Hence, the hardness of the ham slices after this treatment was the closest to that of fresh ham. However, vacuum drying was significantly better than the other two methods in terms of volatile flavor substance contents, which accounted for 98.68% of the total extracts. In addition, the drying method had a significant impact on the rehydration rate and recovery rate (P<0.05). Freeze drying was substantially better than hot air drying and vacuum drying, with the rehydration rate and recovery rate reaching 21.48% and 75.60%, respectively.

30 Effect of Pre-harvest Bagging on the Storage Characteristics of ‘Chili’ Pear Fruit

LU Gui-long , ZHANG Xin-fu , ZHANG Xiao-fei , WANG Ran , YANG Shao-lan

2014, 30(12):176-181.

[Abstract](886) [HTML](0) [PDF 636.93 K](639)

Abstract:
In this paper, the effects of pre-harvest bagging treatments using green transparent plastic and non-woven bags on the texture and physiological characteristics of “Chili” fruits have been discussed. The plants were bagged for 60 days after flowering, and the texture characteristics of the fruits, including hardness, elasticity, viscosity, cohesiveness, and chewiness were determined during fruit storage. The total soluble solids (TSS) content, rate of ethylene release, fruit decay, weight loss, and superficial scald incidence were also measured. The results showed that after storage of 120 d, fruit hardness of non-bagged fruit, plastic-bagged fruit, and non-woven bagged fruit decreased by 23.54%, 42.46%, and 34.40%, respectively; the rate of weight loss was reduced by 20.23%, 30.05%, and 23.30%, whereas the rate of decay was declined by 6.81%, 61.36%, and 17.02%, respectively. Fruits bagged in non-woven bags maintained a slower decrease in hardness and elasticity than did those in the plastic-bagged fruits; the viscosity and cohesiveness of these fruits increased initially and were then maintained at a stable level, with no obvious changes in chewiness. The texture characteristics of fruits stored in non-woven bags were better than of those stored in plastic. The fruits in non-woven bags also shaped a lower ethylene release rate, significantly higher TSS content, and a significantly lower rate of weight loss and decay than those in plastic-bagged fruits. The fruit texture characteristics were also better when stored in non-woven bags. However, the comprehensive storage quality was not as good as those of non-bagged fruits.

31 Effect of Tea Polyphenol-containing Sodium Alginate-Based Edible Coatings on the Quality of Fresh-Cut Kiwifruit

ZHANG Li-hua , ZHANG Pei-qi , ZONG Wei , HU Shao-shuai , WANG Xiao-wen

2014, 30(12):182-187.

[Abstract](1260) [HTML](0) [PDF 743.42 K](732)

Abstract:
In order to extend the shelf-life and maintain the quality of fresh-cut kiwifruit, the effects of different concentrations of tea polyphenols incorporated into a sodium alginate-based edible coating on the soluble solid content, color, total chlorophyll content, ascorbic acid content, total polyphenol content, and total bacterial count of fresh-cut kiwifruit (stored at 4 ± 0.5 ℃) were evaluated. The various groups used in the experiment were the control, sodium alginate-treated (T0), sodium alginate coating containing 1.0% (m/V) of tea polyphenol (T1)-treated, sodium alginate coating containing 1.5% (m/V) of tea polyphenol (T2)-treated, and sodium alginate coating containing 2.0% (m/V) of tea polyphenol (T3)-treated groups. The results showed that the T0 treatment could slow down the decrease of the soluble solid content and total chlorophyll content, but had no significant impact on the L* and a* values. T1, T2, and T3 treatments could, apparently, stop the decline of ascorbic acid and total polyphenol content, significantly reduce the total plate count (TPC) on the surface of fresh-cut kiwifruit, and limit the TPC to within 106 CFU/g after 12-day storage. However, T2 and T3 treatments significantly decreased the L* and a* values of fresh-cut kiwifruit. In conclusion, when the mass fraction of tea polyphenol in the sodium alginate coating was 1.0%, a good quality of fresh-cut kiwifruit could be maintained.

32 Effects of Two Extraction Techniques on in vivo Antioxidant Activity of Grape Seed Oil

GAO Lu , SHEN Yuan , YANG Zhen-quan , RAO Sheng-qi , HUANG A-gen , HU Bo-ran

2014, 30(12):188-193.

[Abstract](1045) [HTML](0) [PDF 534.15 K](682)

Abstract:
In this study, the effects of two extraction methods on in vivo antioxidant activity in a mouse model for aging were evaluated. First, cellulase-assisted and ultrasound-assisted extractions were used to obtain grape seed oil, which was refined and administered by gavage to the aging mice (D-galactose-induced). The contents of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione and peroxidase (GSH-Px) and total antioxidant capacity (T-AOC) in the cerebrum, heart, liver, and serum of the mice were measured. The results showed that the contents of T-AOC, SOD, and GSH-Px in the cerebrum, heart, liver, and serum of the model group all showed different degrees of reduction and the MDA content increased to different degrees, indicating that the mouse model for aging was successfully established. Compared to the model group, each dose group of two kinds of extracted grape seed oil could both enhance the activities of T-AOC, SOD, and GSH-Px and reduce MDA content in the serum and cerebrum, heart, and liver tissues to various degrees. The grape seed oil obtained using cellulase-assisted extraction was slightly superior to that obtained using ultrasound-assisted extraction in terms of enhancing T-AOC and GSH-Px activities. These findings demonstrated that grape seed oil could obviously improve antioxidant activity in the mice; the in vivo antioxidant activity of grape seed oil obtained using cellulase-assisted extraction was slightly higher than that of the grape seed oil obtained using ultrasound-assisted extraction.

33 Comparison of Nutritional and Phenolic Content of Wheat Bran Obtained from Different Sources

LIN Yan-jun , LIU Li-ya , ZHONG Kui , TONG Li-tao , ZHOU Xian-rong , ZHOU Su-mei

2014, 30(12):194-200.

[Abstract](1447) [HTML](0) [PDF 550.00 K](1089)

Abstract:
In this study, the protein, total starch, fat, dietary fiber, pentosan, and the total free, soluble covalently bonded, and bound phenolic substance content in 12 wheat bran samples obtained from nine major wheat production provinces of China were investigated. The differences and correlation between components of the different samples were analyzed statistically. Dietary fibers, proteins, and starch were identified as the three major nutrients in wheat bran, with average contents of 47.30%, 19.85%, and 16.90%, respectively. The total starch and total dietary fiber content varied over a wide range, and the coefficient of variation (CV) was determined to be 19.94% and 8.75%, respectively. However, the protein content varied within a small range, with a CV of 3.16%. Pentosan, the major dietary fiber in wheat bran, was present in an average content of 31.57%. The total phenol content in wheat bran varied between approximately 4470.37 and 5521.30 μg gallic acid equivalents (GAE)/g, with bound phenolic acids constituting 73.9%–79.1%. Bound ferulic acids were the dominant monophenols, with the bran containing as much as 2677.4–3401.8 μg/g ferulic acid content. Many significant (p < 0.01) correlations were also observed between many components. Total dietary fiber and base-hydrolyzed bound phenolic acids (BBPA) showed significant negative correlation with total starch; pentosan and BBPA showed significant positive correlation with dietary fibers; pentosan displayed a significant positive correlation with BBPA; and acid-hydrolyzed bound phenolic acids (ABPA) demonstrated a significant positive correlation with total phenols.

34 Simultaneous Determination of the Contents of 16 Types of Monophenols in Wine, Fruit Wine, and Fruit Vinegar by RP–HPLC

SUN Xiang-yu , DU Guo-rong , MA Ting-ting , LIU Xing-yan , WANG Xiao-yu , ZHAN Ji-cheng

2014, 30(12):201-209.

[Abstract](1292) [HTML](0) [PDF 748.45 K](758)

Abstract:
A new method based on HPLC was established for the simultaneous determination of the contents of eight types of phenolic acids, four types of flavan-3-alcohols, three types of flavonols, and one type of stilbene in natural fruit and vegetable products, including wine, fruit wine, and fruit vinegar. Chromatographic separation was performed using a Waters XBridgeTM Shield RP18 (4.6?250 mm, 3.5 ?m) column at 30 ℃ with an acetonitrile/acetic acid/water mixture as the mobile phase at a flow rate of 0.8 mL/min. The injection volume was 20 ?L; gradient elution was applied and a diode array detector (DAD) was used to monitor signals at 280 nm and 320 nm. All 16 monophenols were successfully separated and their contents showed good linear relationships with the peak areas. The method had a high recovery rate, good repeatability, good accuracy, and high speed. The contents of 16 types of monophenols in three wines, three fruit wines, and three fruit vinegars were determined using this method. The results suggested that fourteen, fourteen, and nine types of monophenols could be quantified in dry red wine, dry white wine, and rosé wine, respectively; seven, seven, and eight types could be quantified in apple wine, cherry wine, and pomegranate wine, respectively; eight, nine, and eight types could be quantified in apple vinegar, persimmon vinegar, and kiwifruit vinegar, respectively. The results indicated that the method was accurate and reliable, and was suitable for the analysis of different monophenols in various fruit and vegetable drinks including wine, fruit wine, and fruit vinegar.

35 Nanographene-tyrosinase-chitosan-based Electrochemical Enzyme Biosensor for Rapid Detection of Bisphenol A

GU Yuan-yuan , PAN Dao-dong , SUN Yang-ying , CAO Jin-xuan , ZENG Xiao-qun

2014, 30(12):210-214.

[Abstract](1432) [HTML](0) [PDF 573.49 K](715)

Abstract:
In this study, an electrochemical, graphene-based biosensor was developed for rapid detection of trace amounts of bisphenol A (BPA). Graphene was prepared by chemical reduction, and its structure and morphology were characterized by using transmission electron microscopy and selected area electron diffraction. Subsequently, graphene, tyrosinase, and chitosan were mixed in an optimized ratio to construct the graphene-tyrosinase–chitosan-modified electrode. Cyclic voltammetry showed that the modified electrode had good electrochemical characteristics. When tested with 0.1 mol?L-1 phosphate buffered saline (pH 7.0), a wide response range for the detection of BPA was obtained with this biosensor, with a low detection limit. The linear range was from 7.5 × 10-8 to 2.5 × 10-6 mol?L-1, the correlation coefficient R2 was 0.996, and the detection limit was 2.18 × 10-8 mol?L-1 (S/N = 3). The results of the stability, reproducibility, and interference tests indicated that the enzyme biosensor prepared in this study exhibited good stability, reproducibility, and high specificity for the detection of BPA. This study provides a sensitive, rapid, and simple method to detect BPA residues.

36 Establishing a Universal Fluorescence Real-time PCR Method for the Detection of Yeast in Food

YU Yi-gang , WAN Song-hua , HU Shuang-fang , XIAO Xing-long , WU Hui

2014, 30(12):215-219.

[Abstract](1176) [HTML](0) [PDF 532.37 K](658)

Abstract:
The aim of this study was to establish a rapid fluorescence real-time PCR method for the detection of contamination in yeast present in food products. For this purpose, a universal probe and primers based on the yeast genome sequence were designed. The reaction system and conditions for fluorescence real-time PCR detection of yeast were established. The method was tested for its specificity, sensitivity, and reproducibility, and was also applied to the examination of food samples. The fluorescence real-time PCR assay was shown to display 100% specificity, as positive results for the specificity test were obtained only in yeast and not in bacteria or mold. The limit of detection of sensitivity was determined to be 760 cfu/mL. The sample was also tested for reproducibility, and the coefficient of variation (CV) was observed to fluctuate in the range of 0.62%~0.81% within the yeast group, and 0.43%~0.77% between groups. Moreover, a yeast enrichment test was performed, which demonstrated that the positive samples could be detected even after 12 h. In summary, the fluorescence real-time PCR assay established in this study showed excellent specificity, high sensitivity, and good reproducibility, in addition to being rapid and easy to use. This method could be used in the rapid detection of yeast contamination in food, and therefore can be used in research and related applications.

37 Photoelectrochemical Method for the Detection of Methyl Parathion Residues in Tomato

DONG Xiao-ya , QIU Bai-jing , GUAN Xian-ping

2014, 30(12):220-224.

[Abstract](1417) [HTML](0) [PDF 632.67 K](714)

Abstract:
Cd0.5Zn0.5S/G nanocomposite was successfully prepared by the in situ doping of graphene (G) with multi-metal sulfide (Cd0.5Zn0.5S). The composite was used to modify the surface of a glassy carbon electrode. Based on the principle of suppression of photoelectrochemical signals by organophosphate pesticides, using methyl parathion as a model molecule, a photoelectrochemical sensor was constructed. The Cd0.5Zn0.5S/G nanocomposites were characterized by scanning electron microscopy (SEM) and electron dispersion spectroscopy (EDS), meanwhile, their photoelectrochemical performance in a buffer solution was also investigated. The result showed that, because of the synergistic effect between Cd0.5Zn0.5S and G, the photoelectrochemical intensity of the Cd0.5Zn0.5S/G nanocomposites was significantly higher than that of pure Cd0.5Zn0.5S and G, thus increasing the sensitivity of the sensor. The constructed sensor was used to analyze methyl parathion solutions with different concentrations, and it exhibited a linear response to methyl parathion over a wide range, from 0.01 to 100 ng mL?1, with a detection limit of less than 5 pg mL?1. The sensor showed excellent reproducibility and stability, and provided an effective approach for the rapid detection of organophosphate pesticides.

38 Molecularly Imprinted Solid-phase Extraction Membrane-high Performance Liquid Chromatography for the Determination of Triazole Fungicide Content in Grains

GAO Wen-hui , WANG Jiao-jiao

2014, 30(12):225-229.

[Abstract](1419) [HTML](0) [PDF 582.12 K](808)

Abstract:
A molecularly imprinted solid-phase extraction membrane (MISPEM) coupled with high-performance liquid chromatography (HPLC) method for the simultaneous determination of four triazole fungicides in grain samples was developed. Residues of bitertanol, triadimefon, diniconazole, and tebuconazole in grains were separated and enriched using the self-prepared MISPEM. These enriched residues were subsequently analyzed by HPLC. Process characteristics such as washing agents, the type and amount of eluents, and the detecting conditions were optimized. For this process, using 5 mL water and 3 mL methanol as the washing agent and eluent, respectively; the samples were separated with a C18 column, using a mobile phase of methanol and water (82:18, V/V). The separation was quantified using an external standard method, by detection at a wavelength of 210 nm. The average recovery rates of the four fungicides were discovered to be between 84.2% and 98.1%; the relative standard deviations (RSDs) ranged from 1.2% to 2.7% (n = 5). The MISPEM showed a good cleansing effect on the samples, as well as strong adsorption capacities for the four fungicides. These results suggest that this method can be used in the efficient, sensitive, and rapid determination of triazole fungicides in grain samples.

39 Determination of Plum Maturity Levels by Using NIR and Chemometrics

NIU Xiao-ying , GONG Dong-jun , WANG Yan-wei , LU Wen-qing , LIANG He , ZHAO Zhi-lei , REN Rui

2014, 30(12):230-234.

[Abstract](1484) [HTML](0) [PDF 625.90 K](916)

Abstract:
Harvest maturity is an important factor that can affect plum quality during the storage period. In order to achieve rapid non-destructive determination of plum maturity level, in this study, 163 plum samples were classified into three maturity levels-early stage (n = 53), middle stage (n = 55), and late stage (n = 55)-according to different fruit development times after flowering. Near infrared spectroscopy (NIR) was used to classify plum samples into different maturity levels. The accuracies of the classification models established by Mahalanobis distances analysis, soft independent modeling of class analogy, and least squares-support vector machine were compared. Mahalanobis distance model with the first 20 principal components (PCs) extracted from original spectra as inputs yielded the best result, and the correct classification rates for calibration set and prediction set were 96.33% and 96.30%, respectively. Soluble solid content (SSC), titratable acid, and firmness were analyzed using single factor one-way analysis of variance (ANOVA). There were significant differences in each index, and the greatest difference was found in SSC. The PCs that were extracted from the data of the three quality indices had very similar clustering tendencies as those extracted from spectrum data. These results showed that combining NIR with chemometrics to discriminate plums of different maturity levels was feasible and effective, and the difference in quality indices could be a physicochemical validation for the classification results from NIR.

40 A Study of Flavonoids from the Leaves of Corylus heterophylla Fisch.

ZHAO Ming-hui , JIANG Zi-tao , LIU Tao , LI Rong

2014, 30(12):235-240.

[Abstract](1018) [HTML](0) [PDF 681.30 K](712)

Abstract:
Qualitative analysis of flavonoids in the leaves of Corylus heterophylla Fisch. was performed using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Compounds were identified by comparison of retention times, parent ions, and secondary ion fragments. Quantitative analysis of the flavonoids was performed using HPLC-ESI-MS/MS in the multiple reactions monitoring (MRM) mode. The results showed that 12 compounds were found in the leaves of C. heterophylla, and 11 compounds were reported for the first time, namely epicatechin (41.45 ± 1.87 μg/g, dry weight), chlorogenic acid (3-caffeoylquinic acid, 389.00 ± 17.15 μg/g), syringetin-3-O-glucoside (6169.78 ± 209.73 μg/g), salvianolic acid C (443.37 ± 21.07 μg/g), chrysoeriol-6-C-glucoside (206.81 ± 10.07 μg/g), hyperoside (quercetin-3-O-galactoside, 154.44 ± 7.63 μg/g), quercitrin (quercetin-3- O-rhamnoside, 937.15 ± 40.86 μg/g), laricitrin-3-O-galactoside (17.27 ± 0.82 μg/g), malvidin-3-O-glucoside (202.74 ± 10.04 μg/g), laricitrin-3- O-glucoside (101.27 ± 4.99 μg/g), and kaempferol-3-O-rhamnoside (112.37 ± 4.77 μg/g).

41 Rapid Determination of Six Zeranols in Biscuits by Dispersive Solid-phase Extraction Coupled with High Performance Liquid Chromatography-tandem Mass Spectrometry

HUANG Jin-feng , XIAN Yan-ping , LI Xiu-ying , CAI Wei-hong , LI He , LIN Sen-yu , HE Min-heng , GUO Xin-dong

2014, 30(12):241-246.

[Abstract](1317) [HTML](0) [PDF 715.54 K](925)

Abstract:
A simple and rapid analytical method was established for the determination of six zeranols (α-zearalanol, β-zearalanol, α-zearalenol, β-zearalenol, zearalanone, and zearalenone) in biscuits by dispersive solid phase extraction (d-SPE) coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). After the addition of the isotopic internal standard, the sample was dispersed in water, and zeranols were extracted using a solvent mixture of acetonitrile/formic acid (99:1). Subsequently, the sample was mixed with sorbents PSA, C18, and MgSO4 to conduct d-SPE. The solution was concentrated under a nitrogen stream and reconstituted in a 30% acetonitrile (v/v) solution. After being defatted with n-hexane, the sample was separated and analyzed by HPLC-MS/MS. Negative electrospray ionization was used on a quadrupole mass spectrometer operating under multiple reaction monitoring (MRM) mode. The quantitation was carried out using the internal standard method. The calibration curves of the zeranols were linear in the range 0.20-50.0 μg/L with correlation coefficients higher than 0.996. The limits of detection (LODs) and the limits of qualification (LOQs) of the method varied from 0.03 to 0.11 μg/kg and from 0.11 to 0.31 μg/kg, respectively. The mean recoveries of the zeranols ranged from 70.9% to 107.1%, with intraday precisions (n = 6) and interday precisions (n = 5) less than 12%. This method provides good purification and accurate quantification, and is sensitive, rapid, and suitable for the identification and quantification of the six zeranols in biscuits.

42 Analysis and Comparison of Volatile Flavor Compounds in Different Styles of Chinese Traditional Bacon

GUO Xin , ZHANG Chun-jiang , HU Hong-hai , HUANG Feng , ZHANG Hong

2014, 30(12):247-254.

[Abstract](943) [HTML](0) [PDF 692.83 K](956)

Abstract:
In this work, the discrepancies in the volatile flavor compounds found in Hunan-, Sichuan-, and Cantonese-style bacons were studied using an electronic nose and headspace solid-phase microextraction method combined with gas chromatography-mass spectrometry (SPME-GC-MS). Principal component analysis based on data obtained from the electronic nose showed significant differences in the aromatic characteristics of Cantonese-style bacons and the other two styles of bacons, while the aromatic characteristics of Hunan-style bacons were similar to those of Sichuan-style bacons. For the Hunan-, Sichuan-, and Cantonese-style bacons, 32, 38, and 42 volatile flavor compounds were identified, respectively, including hydrocarbons, alcohols, aldehydes, ketones, esters, and furans. The only volatile components detected in all three styles of bacon were undecane, dodecane, tetradecane, and 2,6,10,14-tetramethylhexadecane. In Sichuan- and Hunan-style bacons, 25 volatile flavor compounds were identified, including 2-methylphenol, 2-methoxyphenol, 2-methoxy-5-methylphenol, and 2-furanmethanol. On the other hand, although most of the aldehydes and alcohols, as well as all the esters were detected in Cantonese-style bacons, phenols and furans were not detected. The results of this study could provide a theoretical reference for the development and control of typical flavor compounds in Chinese traditional bacons during their processing.

43 Characteristic Aroma Components and Sensory Properties Analysis in Different Types of Lavender Essential Oil from Xinjiang

HUANG Mei-gui , LI Chun-yang

2014, 30(12):255-262.

[Abstract](1815) [HTML](0) [PDF 635.74 K](802)

Abstract:
Essential oils from five types of lavender flowers (namely 70-1, 74262, Miscellaneous flower, France blue, White flower) in Xinjiang were extracted by water vapor distillation. Volatile components and characteristics of aroma components in lavender essential oils were analyzed using gas chromatography- mass spectrometry (GC- MS), and the aroma profiles were investigated by sensory evaluation. Results showed that 70-1 oil had the highest content (6.88%) among five types of lavender essential oils. The volatile components in lavender essential oils were mainly terpenes, esters, alcohols, aldehydes and ketones. White flower essential oil had the highest kinds and content of volatile components. The biggest difference in volatile components was terpene, which the content of five types of essential oils was 17.15%, 12.36%, 16.33%, 16.16%, 16.33%, respectively. The content of characteristic aroma components in five types of lavender essential oils such as linalool and linalyl acetate, had significant difference. Essential oil of 74262 type had the strongest flower smell and ester aroma flavors. Therefore, the flavors as flower smell, ester aroma, chill, wax oil and terpene smell in five types of lavender essential oils presented the significant difference was mainly for the variety and volatile components.

44 Effect of Yeast Strains on the Aromatic Composition of Kiwifruit Wine

ZHOU Yuan , BEN Hao , FU Hong-fei

2014, 30(12):263-270.

[Abstract](1210) [HTML](0) [PDF 816.29 K](667)

Abstract:
The aroma of kiwifruit wine is closely dependent on the yeast strains used for fermentation. In this study, yeast strains were isolated from kiwifruit peel, and strains suitable for kiwifruit wine fermentation were obtained after purification, screening, and identification. The effects of the screened strains on the aromatic composition and content of kiwifruit wines were determined by gas chromatography coupled with mass spectrometry (GC-MS). The results showed that two screened yeast strains (1-21 and 1-31) were identified as Saccharomyces cerevisiae (baker’s yeast) and Issatchenkia orientalis, respectively, by using 26S rDNA sequencing. Compared with the commercially available yeast strain, the screened yeast strain 1-21 showed a stronger fermentation capacity, stronger acid resistance, and produced higher ascorbic acid content in wine. In contrast, strain 1-31 was more resistant to high sulfur dioxide concentration and produced a unique aroma in wine. By comparison, characteristic differences in the aromatic composition and content were found in the kiwifruit wines fermented using different yeast strains. Among the 49 identified aromatic compounds, 13 were common aromatic components, eight were only found in the kiwifruit wine fermented using strain 1-21, and seven were only found in the kiwifruit wine fermented using strain 1-31. In addition, the aromatic compound content in kiwifruit wines fermented using the screened strains was significantly higher than that in kiwifruit wine fermented using a commercially available yeast strain. Therefore, the screened yeast strains 1-21 and 1-31 were considered more suitable for producing the characteristic aroma of kiwifruit wine.

45 Analysis of Volatile Components of Kaempferia galanga L. from Guizhou by Solid Phase Microextraction and Gas Chromatography-Mass Spectrometry

LUO Jing , WU Di , ZHONG Yong-ke

2014, 30(12):271-276.

[Abstract](866) [HTML](0) [PDF 630.77 K](681)

Abstract:
The volatile components of Kaempferia galanga L. from Guizhou were analyzed using gas chromatography-mass spectrometry (GC-MS) coupled with solid phase microextraction (SPME). The volatile components were also compared with those of Kaempferia galanga L. from Guangxi using the same techniques in combination with Fourier transform infrared (FT-IR) spectroscopy. The volatile components of Kaempferia galanga L. from Guizhou were different from those from Guangxi. The main components were estragole, followed by 5(1H)-azulenone, 2,4,6,7,8,8a-hexahydro-3,8-dimethyl-4-(1-methylethylidene), and seychellene. Using the peak area normalization method, the detectable components with over 90% matching were statistically analyzed. Notably, 47 volatile components were detected in Kaempferia galanga L. from Guizhou, and the three major components comprised most of the contents: estragole at 61.53%, 5(1H)-azulenone, 2,4,6,7,8,8a-hexahydro-3, 8-dimethyl-4-(1-methylethylidene) at 15.54%, and seychellene at 7.19%. Moreover, the 47 identified volatile components included ethers (4), ketones (3), terpenoids (28), phenolic compounds (3), alcohols (2), esters (2), aldehydes (2), and hydrocarbons (3). Among them, ethers, ketones, and terpenoids comprised 62.22%, 15.83%, and 13.68% of the total composition, respectively.

46 Analysis of Petroleum Ether Extract from Soybean Dreg by FT-IR and GC/MS

GONG Gui-zhen , SUN Cong-yan , ZHANG Da-qing

2014, 30(12):277-281.

[Abstract](1110) [HTML](0) [PDF 643.52 K](784)

Abstract:
In order to understand the chemical speciation of small molecules in soybean dreg, they were was extracted with petroleum ether using a Soxhlet extractor. The petroleum ether extract was analyzed by Fourier transform infrared (FT-IR) spectroscopy and gas chromatography/mass spectrometry (GC/MS). The raw bean dreg and the residue from the extraction were also analyzed by FT-IR spectroscopy. A pale yellow oil was obtained from the petroleum ether extract after 5-hour continuous extraction, with an extraction yield of 10.7%. FT-IR band shapes were similar for the raw material and the residue from extraction, but with different absorption intensities, while obvious differences in the FT-IR spectra were found between the petroleum ether extract and raw bean dreg/the residue from the extraction. In total, 35 compounds were identified from the petroleum ether extract, which can be classified into seven groups: alkanes, alkenes, arenes, aldehydes, acids, esters, and other species. Among them, the esters were the most abundant compounds, with a relative content of 61.79%. This study was important for the basic theory on developing the value-added utilization of soybean dreg.

47 Optimization of Capillary Electrophoresis for the Determination of Amylose/Amylopectin Content in Chinese Yam Starch

WANG Li-xia , LI Bin , YANG Shi-wei , CAO Jin-li , LIU Xiang-hua , ZHANG Kai

2014, 30(12):282-286.

[Abstract](1337) [HTML](0) [PDF 519.45 K](824)

Abstract:
Chinese yam powder was prepared by limewater immersion with fresh, commercially available Dioscorea opposita as the raw material; amylose and amylopectin were separated and purified by repeated recrystallizations using n-butanol. Using iodine ions as chromogenic agents, capillary electrophoresis was used to determine the content and ratio of amylose and amylopectin in Chinese yam starch. In this study, the use of different buffers, such as citrate-phosphate and acetate acid-acetate, was compared. The acetate acid-acetate buffer was found to be superior in the separation of amylose and amylopectin. Subsequently, the separation effects of acetate acid-acetate buffer under different pH values were compared and the electrophoretic mobilities were measured. When the pH was 4.8, the best separation effect was obtained, with an electrophoretic mobility of 15.4. Under the optimized conditions, the retention time of amylopectin and amylose was 1.8 min and 2.9 min, respectively, with pure potato amylose and amylopectin as the standards. Dioscorea opposita starch was analyzed, and the amylose content was found to be 19.49%. Repeatability and recovery experiments confirmed the suitable accuracy and precision of this method.

48 Aroma-producing Components of Cuiyu Tea Leaves during Different Seasons by GC-MS

LAI Xing-fei , PANG Shi , LI Yu-nan , XU Ping , PAN Shun-shun , SUN Shi-li

2014, 30(12):287-293.

[Abstract](1094) [HTML](0) [PDF 583.13 K](766)

Abstract:
The aroma-producing components in Cuiyu green tea (CGT), Cuiyu black tea (CBT), and Cuiyu Oolong tea (COT) prepared from Cuiyu tea leaves (harvested during spring, summer, and autumn from Guangdong Province, China), were studied by using gas chromatography and mass spectrometry (GC-MS). The results revealed that CGT prepared from tea leaf samples collected during spring and summer contained a larger variety of aroma-producing components than those collected during the fall season. The results for individual components in the spring and summer samples for CGT were similar, where alcohols showed the highest relative content, while pyrroles and their derivatives showed the highest relative content in autumn samples. CGT from spring samples showed the largest number of dominant aroma-producing components, most of which were of floral aroma, CGT from summer samples showed that the dominant components comprised of alcohols (>59%), while CGT from autumn samples showed the lowest number of these dominant components. The aroma-producing components of CBT from different seasons were similar; alcohols consistently showed the highest relative content, and the alcohol proportion was also the highest in CBT when compared with other teas. The dominant aroma-producing components of CBT from different seasons were similar and mainly comprised of nerol, trans-nerolidol, and trans-linalool oxide. The aroma-producing components of COT from different seasons showed a distinct pattern, including mainly alcohols, pyrroles and their derivatives. COT from spring and summer samples showed a larger number of dominant aroma-producing components. Similar components were found in COT from autumn samples, where the characteristic components were trans-nerolidol and indole.

49 Progress in Functional Lipid Nanodispersion Research

ZHONG Jin-feng , QIN Xiao-li

2014, 30(12):294-301.

[Abstract](1098) [HTML](0) [PDF 567.63 K](736)

Abstract:
Functional lipids such as carotenoids, phytosterols, lipid-soluble vitamins, and n-3 polyunsaturated fatty acids, have high nutritional value and important physiological functions. However, the use of functional lipids in the food and pharmaceutical industries is restricted due to its low solubility resulting in poor absorption in the gastrointestinal tract and low bioavailability in the digestive system from food containing functional lipids. Therefore, improving water solubility, stability during storage, and bioavailability of functional lipids is an immediate requirement. Functional lipid nanodispersions, prepared by using nanotechnology have the potential to improve the solubility and bioavailability of functional lipids, thus expanding the use of functional lipids in the food industry. Based on previous reports on functional lipid nanodispersions in literature, the authors present a review of the requirements and preparation methods for functional lipid nanodispersions. Additionally, the factors affecting the physicochemical stability of functional lipids in the nanodispersion system as well as the bioavailability and food safety of functional lipid nanodispersions are discussed. Finally, the scientific issues and areas of current research on functional lipid nanodispersions are summarized and the prospect of future research is discussed.

Home

About the journal

Notes for submission

Acceptable topics

Author garden

Open access

中文

Volume 30,Issue 12,2014 Table of Contents