Volume 29,Issue 5,2013 Table of Contents

1 Founctional Properties of Wheat Gluten Influenced by Dynamic High Pressure Microfluidization Treatment

LIU Guo-qin , YAN Nai-jun , CHEN Lu-yao

2013, 29(5):936-940.

[Abstract](1194) [HTML](0) [PDF 545.68 K](679)

Abstract:
The effect and mechanism of dynamic high pressure microfluidization (DHPM) on functional properties of gluten protein was investigated. The results showed that DHPM could change the functional properties of gluten protein and there was close relationship between the changes in functional properties and the pressure of DHPM or protein concentration. When the concentration was above 4% the solubility was increased and then decreased with the increase of pressure. When the concentration was less than 4% the solubility was decreased and then increased with the increase of pressure, with the limit of 80 MPa. When the concentration was 4%, the foaming ability decreased and the foaming stability, emulsifying ability and emulsifying stability increased with the increase of pressure; while the opposite as the other concentration such as 2% and 6%. SDS-PAGE and DSC analysis indicated that high molecular weight subunit was destroyed and some new aggregation was formed, which changed the functional propertied of gluten protein.

2 Hypolipidemic Function of Auricularia polytricha Protein Extract

ZHAO Shuang , LIU Yu , XU Feng , WANG Shou-xian , CHEN Jie , GENG Xiao-li

2013, 29(5):941-944.

[Abstract](1202) [HTML](0) [PDF 556.24 K](660)

Abstract:
The hypolipidemic functions of Auricularia polytricha was investigated in this research. The results showed that Auricularia polytricha could decrease the cholesterol level significantly in vivo. The protein component was then extracted and its hypolipidemic function in vivo towards rats was studied. It was found that the protein extract of Auricularia polytricha could decrease the levels of cholesterol, triglycerides and low-density lipoprotein cholesterol in blood with the ratio of 28.4%, 22.95% and 42.14%, respectively. The protein extract also could relief the degree of fat liver. Auricularia polytricha protein extract could be applied in preparation of health supplement

3 Properties of Waxy Corn Starch Treated in Different Aanhydrous Alcohols with Hydrochloric Acid

LIN Hua-shan , HUANG Wei , LUO Zhi-gang

2013, 29(5):945-947.

[Abstract](1169) [HTML](0) [PDF 514.18 K](720)

Abstract:
The physicochemical properties of waxy corn starch was studied before and after treated in anhydrous alcohols with acid. Waxy corn starch was treated in anhydrous methanol, ethanol, 2-propanol and 1-butanol with hydrochloric acid. The results showed that the surface was porous after starch acid-alcohol treated, and the fissure on the surface of granules could be observed with the increasing of carbon number of alcohol. Acid-alcohol treatment decreased syneresis and the swelling power and increased the solubility as the increasing of carbon number of alcohol from ethanol to 1-butanol. The X-diffraciton pattern did not changed, but the intensities of the major d-spacings decreased after acid-alcohol treatment. The foregoing data showed starch could be made more susceptible to acid hydrolysis in different alcohols from methanol to 1-butanol.

4 Evaluation of the Preservation Methods for Two Microalgal Concentrates

YU Jian-zhong , LIANG Xin-xin , CHEN Feng , WEI Dong

2013, 29(5):948-952.

[Abstract](1433) [HTML](0) [PDF 466.54 K](892)

Abstract:
Various cryoprotectants and cooling methods were adopted for 3-month preservation of the concentrates of Nannochloropsis oculata (2×109 cells/mL,at 4 ℃ and -18 ℃) and Spirulina platensis (7% dry weight at -18 ℃). The results showed that, the highest relative cell activity of N. oculata concentrates preserved for 3 months reached 48.17% of that control (fresh cultured cells) by fast freezing at -18 ℃ without cryoprotectant, which higher than other treatments significantly (P<0.05). Under the same conditions, the loss of protein and EPA in the concentrates of N. oculata had were 3.42% and 2.73%, respectively,The lose of the protein and total fat acids in the concentrates of S. platensis were 4.17% and 19.33%, respectively. Based on the systematic comparison, the method of fast freezing at -18 ℃ without cryoprotectant was determined as the favorable for preservation of the concentrates of N. oculata and S. platensis at low temperature.

5 Use of Refrigerated-seawater Spray in Keeping Haliotis discus hannai Alive at Ecological Ice Temperature

NI Jin , SHEN Jian

2013, 29(5):953-956.

[Abstract](1143) [HTML](0) [PDF 541.20 K](751)

Abstract:
The ice temperature zone of hannai was obtained by measuring its freezing curve and then the technologies for keeping Halitotis discus hannai alive at ecological ice temperature were investigated. Results show that the survival rate of Haliotis discus hannai is the highest while it was kept alive at ecological ice temperature (-1.5 ℃~0 ℃). The treatments by gradient freezing, refrigerated seawater spray, cleaning and oxygen supplement were good for Haliotis discus hannai’s survival rate improvement. The best processing conditions for keeping alive were: cleaning Haliotis discus hannai ,then gradient freezing it to ecological ice temperature by spraying refrigerated seawater with oxygen supplely, and continuing spraying refrigerated seawater and supplying oxygen and moisture environment during the keeping-alive stage. Key words: Haliotis discus hannai; ecological ice temperature; keeping alive; refrigerated seawater spraying

6 Preparation and Mechanical Property of Soy Protein Porous Hydrogel

JIN Yu-cong , YANG Xiao-quan , GUO Jian

2013, 29(5):957-960.

[Abstract](934) [HTML](0) [PDF 463.26 K](696)

Abstract:
Soy protein porous hydrogel was prepared by microbial transglutaminase (MTGase) induced cross-linking and high speed homogenizing in this work. Computed microtomography was used to observe the microstructure of the porous hydrogel. The effects of the preparation conditions on the mechanical properties of the hydrogel were also evaluated. The results indicated that porous hydrogels with different porosity and textures could be obtained by regulating the dosage of MTGase, homogenizing speed and soy protein isolates (SPI) dispersion pre-heating temperature. When SPI dispersion was pre-heated at 95 ℃for 30 min, added with 6.67 U MTGase/g SPI, and then homogenized at 8000 r/min for 30 s, porous hydrogel can be achieved with uniform distribution of pore, better strain, highest stress and Young’s modulus.

7 Effects of Isopropanol Concentrations on Properties of Zein Film Produced by Casting

LIU Jun , CHEN Ye , ZHOU Shu-hong , ZHANG Ming , WANG Jun-yu

2013, 29(5):961-964.

[Abstract](1107) [HTML](0) [PDF 603.61 K](750)

Abstract:
The tensile strength, water vapor permeability, water absorption and the contact angle of zein film were investigated, in order to study the influence of isopropanol concentrations on the properties of zein film. Experimental results showed that increase in the isopropanol content of solvent, the tensile strength of zein film increased until it reached a maximum about 57.7 MPa at 90% isopropanol content. As the isopropanol content of solvent increased from 70% to 95%, both WVP and water absorption of the zein film decreased and the minimum were about 0.075?10-8g?m/(m2?h?Pa) and 37.2%, respectively, at 90% isopropanol content. The contact angle experiment indicated that contact angle of zein film produced from 90% isopropanol solution was 67°and showed good waterproof properties. Measurement of AFM showed that zein dissolved in isopropyl alcohol solution formed orderly agglomerations and agglomerations condensed each other, resulting in a network structure. DSC results showed that denaturation temperature of zein film was higher than zein degeneration temperature.

8 Development on Flavonoids and Antioxidant Activity of Tartary Buckwheat Sprout

WANG Jing-bo , ZHANG Jiang-lin , PENG Lian-xin , ZOU Liang , XIANG Da-bing , ZHAO Gang

2013, 29(5):965-968.

[Abstract](1227) [HTML](0) [PDF 438.06 K](782)

Abstract:
Rutin and quercetin content in tartary buckwheat sprout were analyzed by HPLC. The DPPH and ABTS radical scavenging capacity of tartary buckwheat seed and sprout ware measured by spectrophotometry. The results showed that the dynamic changes of flavonoids in tartary buckwheat were increased on day 1 to 10 and reach its peak on day 10. After germination, the antioxidant capacity of tartary buckwheat sprout had significantly improved.

9 Extraction and Antioxidant Activity of Polyphenols from Pear

ZHAO Xu , ZHENG Bi-sheng , ZHOU Meng

2013, 29(5):969-972.

[Abstract](1242) [HTML](0) [PDF 612.08 K](688)

Abstract:
This study was designed to investigate the extraction of free and bound phenol from the peels and the flesh of pear by solvent extraction method. The antioxidant activity of the peels and the flesh was also studied using the DPPH? assay. The results showed that the total phenol in peels was 201.26±6.90 mg gallic acid equivalents per 100 g fresh pear peels, including 135.36±1.57 mg soluble free phenol and the 42.46±3.05 mg bound phenol. And the total phenol in the flesh was lower with the value of 23.73±2.28 mg gallic acid equivalents per 100 g fresh pear flesh, including 12.54±0.98 mg soluble free phenol and 11.19±1.30mg bound phenol. The content of the flavonoid had a positive correlation with the content of the total phenol. Comparing the antioxidant activities of the peels and fresh, the free phenol in pear flesh had the highest antioxidant activity, with the values of DPPH? scavenging rate EC50 and AE being of 248.59 μg/mL and 0.0040, respectively. The bound phenol in the pear fresh had the lowest antioxidant activity, with the values of DPPH? scavenging rate EC50 and AE being of 1043.24 μg/mL and 0.0010, respectively.

10 Influence of Packaging Methods on the Preserve Quality of Hemi-dried Litchi Fruits

LIU Yuan , HUANG Wei , HU Zhuo Yan , ZHENG Run-xin

2013, 29(5):973-977.

[Abstract](1157) [HTML](0) [PDF 601.64 K](609)

Abstract:
In order to inhibit browning and microbial growth during the storage of the hemi-dried litchi fruits, the moisture content distribution and water activity of hemi-dried litchi fruits were investigated to explore the effect of packaging processes and materials on the storage of hemi-dried litchi fruits. The results showed that the average moisture content of hemi-dried litchi fruits was 36.51%, and the average aw >0.73. Deoxidizing packaging technology can inhibit enzymatic browning effectively and had significant bacteriostatic effect. It was found that there was a synergetic effect between preservative and deoxidizer and the opacity of packaging materials have no obvious influence on browning. Using common packing technology, hemi-dried litchi fruit browning was fast and similar storage effect was found between different packing materials. Therefore, the cost and appearance can be used as the standards to choose the packaging materials when using common packaging.

11 Effect of Different Pressure on the Hypobaric Storage of Pleurtus ostreatus

WANG Shi-kui , MU Qi-yun , LI Wen-xiang , WANG Li-jiao , ZHANG Sheng-jie , SUN Shu-jie

2013, 29(5):978-981.

[Abstract](920) [HTML](0) [PDF 460.97 K](736)

Abstract:
In order to study the effect of different pressure conditions on the hypobaric storage of Pleurotus ostreatus, the physiologic and biochemical changes of Pleurotus ostreatus under different pressure (30~40 kPa,50~60 kPa and 70~80 kPa) were studied and compared with that under modified atmosphere packaging storage (MAP). The results showed that hypobaric conditions could inhibit the respiratory intensity, delay the decline of soluble protein content, reduce the rising of browning degree and the increasing of relative leakage rate effectively. And the weight loss showed little difference contpared to the control group (P>0.05). Pleurotus ostreatus had a better preservation performance under 50~60 kPa than those under 30~40 kPa and 70~80 kPa (P<0.05).

12 Identification and Screening of Bacteriocin-producing Tetragenococcus halophilus

WANG Lin-lin , ZOU Yuan-jun , XIANG Song-tao , ZHANG Yun-ling , ZHENG Yi-min , XU Xiu-ying

2013, 29(5):982-985.

[Abstract](1039) [HTML](0) [PDF 330.48 K](761)

Abstract:
Twelve strains lactococcus was isolated from the traditional Chinese soy. the physiological and biochemical characteristics and the 16SrDNA sequence of the screened strain were then analyzed, based on which the strain was identified as Tetragenococcus halophilus. The supernatant of WZ-3 strain eliminate the organic acids exhibited strong antibacterial activity against the gram-positive and gram-negative bacteria. The antibacterial activity decreased slightly after treatment with pepsin and trypsin, therefore, we think the strain was a bacteriocin-producing Tetragenococcus halophilus.

13 Effect of Carrageenan/Locust Bean Gum on the Properties of Comminuted Pork

ZHUANG Pei-rui , YANG Yuan-yuan , SUN Wei-zheng , CHEN Chu-rui

2013, 29(5):986-988.

[Abstract](1335) [HTML](0) [PDF 429.37 K](746)

Abstract:
Hydrocolloids are a food additive used to improve the quality of meat products. Carrageenan, locust bean gum and their combination were added during comminuted pork processing. The changes of colour, texture and water activity were measured to determine their effects on quality of comminuted pork. Results showed that carrageenan and locust bean gum in an appropriate proportion can ameliorate the texture property of comminuted pork. By addition of 0.16% carrageenan and 0.24% locust bean gum,the obtained pork showed the best texture property, with hardness value, chewiness value and water loss rate being of 521.20±15.40, 27.00±10.40 and 0.040±0.002, respectively.

14 Kinetics Study of Batch Fermentation of Rhamnolipid by Pseudomonas aeruginosa SFZ-37

ZHAO Chen , ZHAO Xiang-ying , DONG Xue-qian , QIAO Jun , LIU Jian-jun

2013, 29(5):989-992.

[Abstract](1428) [HTML](0) [PDF 529.27 K](908)

Abstract:
To explore rhamnolipid production by Pseudomonas aeruginosa SFZ-37, batch fermentation was conducted in a 5-L fermentor and the fermentation process was monitored. During the batch fermentation, the pH was almost constant. At the end of batch fermentation, the dry cell weight, rhamnolipid production and residual glycerol could reach 4.41 g/L, 11.61 and 11.69 g/L, respectively. Based on the experimental data of batch fermentation, the kinetic models of cell growth, product formation and substrate consumption were established. The non-line fitting was employed to model the kinetics of fermentation by software OriginPro 8.0. The kinetic model could be used to describe the relationship of cell growth, product formation and substrate consumption during the process of batch fermentation.

15 Breeding of a New Aspergillus oryzae Strain for Fructosyl-transferase Production by Protoplast Fusion of Asymmetric Inactivated Parents

HE Xiao-ni , JIANG Bo , WANG Yu-hai , ZHANG Yi , CHEN Zi-jian

2013, 29(5):993-997.

[Abstract](1193) [HTML](0) [PDF 487.74 K](765)

Abstract:
Screening with enzyme activity and biomass of cell, two mutants (UV-A and UV-B) were obtained from Aspergillus oryzae sbb201 that have been treated with ultraviolet joint lithium chloride mutagenesis. These two parent protoplasts were inactivated with ultraviolet and thermal method respectively, and then fused by PEG induction. A mutant strain was finally obtained which has showed a higher activity of fructosyl-transferase. The enzyme activity reached 172.95 U/g, increased by 64.57% compared with that of the original strain.

16 Effect of Transglutaminase on the Free Primary Amine of Soy Protein Isolate

ZHANG Jing-jie , ZHOU Zheng-yan , CHEN Jun-an , ZHAO Zheng

2013, 29(5):998-1002.

[Abstract](949) [HTML](0) [PDF 681.63 K](717)

Abstract:
The content of free primary amine in the solution was determined by spectrophotometric assay according to that ο-phthaladehyde (OPA) reagent and primary amine could occur fluorescence reaction. The effect of dosage, reaction temperature, time and pH of transglutaminase (TGase) treatment on the free primary amine of soy protein isolate (SPI) was investigated with this method, and the influencial factors were optimized by response surface method. The results showed that the optimal reaction condition was TGase dosage 20 U/g, temperature 52 ℃, time 60 min and pH 7. After TGase-catalyzed modification, the free amine content of SPI were reduced from 0.059 μmol to 0.028 μmol.

17 Isolation and Identification of the Chemical Constituents of Gynura divaricata (L.) DC

ZHENG Xi-Kang , WANG Qin , JIANG Lin , WANG Xiao-Juan , CHEN Jin-Long

2013, 29(5):1003-1005.

[Abstract](1252) [HTML](0) [PDF 493.24 K](734)

Abstract:
Nine compounds were isolated from Gynura divaricata (L.) DC and identified as kaempferol-3-O-α- L- rhamnopyranoside (1), quercetin-3-O-α-L-rhamnopyranoside (2), caryolane-1,9β-diol (3), eudesm-4(14)-ene-3α,11-diol (4), ferulic acid (5), pinoresinol-4-O-β-D- glucopyranoside (6), scopoletin (7), zingerone-4-O-β-D-glucopyranoside (8) and (3R)-3-hydroxy-4, 4-dimethyl- 4-butyrolactone (9) , by analysis of chemical evidence and spectroscopic data. All compounds were isolated from the genus Gynura.

18 Effect of Processing Methods on Sensory Quality of Fried Taro Chip

YANG Wei-lai , WU Wei-guo , LI Chao

2013, 29(5):1006-1009.

[Abstract](956) [HTML](0) [PDF 348.89 K](616)

Abstract:
The fried taro chip was prepared with three processing methods. The oil content and texture of fried taro chip were investigated. And the effects of thickness, drying time and frying temperature on sensory quality of taro chip are studied. The results showed that the optimum conditions were as follows: thickness of slices 2.5 mm, cooking 3 min, drying time 60 min at 40 ℃, quick-freezing temperature -18 ℃, and frying time 120 s at 180 ℃. Under those conditions, the fried taro chip showed the highest sensory quality.

19 Changes of Free Amino Acids in Saba Ham during Fermentation

WANG Yan , JI Jie-li , ZHU Ren-jun

2013, 29(5):1010-1013.

[Abstract](1185) [HTML](0) [PDF 420.13 K](643)

Abstract:
The contents of amino acids in the leg back side muscle between femur and hip in Saba ham were determined by amino acid analyzer during fermentation. The results showed that the free amino acids in the muscles during fermentation first increased and then decreased. In the middle of fermentation, the content of free amino acids reached the largest value, accounting for 5.39% of the products. The free amino acids with high contents were Glu, Lys, Phe and Ile, and the lower-content ones were Cys, Pro, Tyr and Arg. Different free amino acids may play an important role of Saba ham flavor.

20 Nutrient Analysis and Evaluation of Scophthalmus maximus Skirts

TENG Yu , LI Juan , GUO Xiao-hua , YUAN De-shun , WANG Cai-li

2013, 29(5):1010-1111.

[Abstract](1143) [HTML](0) [PDF 405.83 K](785)

Abstract:
The nutrition constituents in Scophthalmus maximus skirts were analyzed in this research.The results showed that the contents of crude fat and total amino acids content in Scophthalmus maximus skirts reached up to 4.2% and 12.22%, respectively. The contents of essential amino acids and flavour amino acids occupied 20.81% and 59.2% of total content respectively. And index of essential amino acids was 91.3. Scophthalmus maximus skirts were rich in minerals and its non-essential minerals accorded with the requirements of GB18406.4-2001. Considering that the first limited amino acid being of valine with higher content of lysine, Scophthalmus maximus skirt was not an ideal protein source but a kind of safe reinforcing food with soft and delicious feeling.

21 Screening and Fermentation of Fibrinolytic Enzyme-producing Strains from Cordyceps militaris

BAI Wei-fang , GUO Li-qiong , LIN Jun-fang , KANG Lin-zhi , ZENG Hou-ru

2013, 29(5):1014-1018.

[Abstract](945) [HTML](0) [PDF 513.90 K](679)

Abstract:
Cordyceps militaris was one of the most popular edible mushrooms. It is a nutritious food source and contains bioactive metabolites with several medicinal effects including anti-tumor, hypocholesterolemic, antioxidant and anti-diabetic activities. In this study, fibrin fibrinolytic enzyme-producing strains were screened from Cordyceps militaris by plate method and specific activity. The fermentation conditions of the fibrinolytic enzyme producing were investigated. The results showed that the best fermentation medium contained 2% glucose, 2% peptone and 1/1 the ratios of carbon to nitrogen. The optimum fermentation conditions were pH 6.0, the temperature 25 ℃, the rotation speed 150 r/min, the fermentation time 9 d, the inoculum size 2% and medium volume 60 mL. Under such conditions, the fibrinolytic enzyme activity was 111.85 U/mL.

22 Effects of Reaction Conditions on the Aldehyde Content of Dialdehyde Yam Starch

ZHANG Li-ming , LI Zheng-jun , ZHANG Xiao-bian , WANG Yu-gao

2013, 29(5):1019-1022.

[Abstract](1589) [HTML](0) [PDF 369.47 K](758)

Abstract:
Dialdehyde starch is prepared with yam starch as raw materials and NaIO4 as an oxidant. The effects of reaction conditions, such as temperature, reaction time, pH value, concentration of starch solution and mole ratio of sodium periodate to yam starch on the aldehyde content in the product were investigated. The experimental results showed that dialdehyde starch could be prepared at 40 ℃ for 4 h with other conditions of pH value 4, the concentration of starch solution 20%, the mole ratio of sodium periodate to yam starch 1.1:1 and the aldehyde content of final product reached 97.5%.

23 Optimization of Enzymolysis Technology and Antioxidant Activity from Protein of Pneumatophorus japonicas

WANG Xue-qin , XING Rong-e , LIU Song , YU Hua-hua , LI Peng-cheng

2013, 29(5):1023-1028.

[Abstract](1206) [HTML](0) [PDF 530.42 K](786)

Abstract:
The effects of trypsin, acid protease, papain, flavor protease and neutral protease on the degree of hydrolysis of Pneumatophorus japonicus meat and by-products (heads, tails and viscera) were studied. The results showed the flavor protease was the most suitable protease and the hydrolysis conditions were optimized by orthogonal test. The optimal hydrolysis conditions of meat were enzyme dosage 1200 U/g, liquid-to-solid ratio 1:15, pH 5.5, temperature 48 ℃ and time 6.5 h, under which the degree of hydrolysis was 37.8%. The optimal hydrolysis conditions of by-products were the enzyme concentration 1200 U/g, liquid-to-solid ratio 1:8, pH 6.0, temperature 48 ℃ and time 6.5 h, under which the degree of hydrolysis was 37.1%. In vitro antioxidant activity test showed that the meat and by-products hydrolyzate exhibited obvious reducing power and hydroxyl radical scavenging activity, with the EC50 of 0.58 mg/mL and 0.28 mg/mL, respectively. The freeze-drying products of meat and by-products were yellow powder and contained variety of amino acids, with the essential amino acids of 38.53% and 43.17%, respectively. The study provided theory basis for exploring Pneumatophorus japonicus.

24 Fast Preparation of Preserved Eggs by Low-pressure Technology

JI Ling , LIU Hui-ping , YANG Xiao-xing , YUAN Wei , LIU Ping-wei

2013, 29(5):1029-1035.

[Abstract](792) [HTML](0) [PDF 521.16 K](825)

Abstract:
The fast preparation conditions for preserved egg by low pressure-vacuum were investigated and optimized by analyzing the influence of temperature, vacuum degree, vacuum-maintaining time on egg quality indexes. Orthogonal test showed that the optimum conditions were: temperature 23 ℃, vacuum -0.10 MPa and evacuation time 24 h per day. Compared with ordinary method, the preserved eggs by low pressure-vacuum method needed shorter curing time from 25 days to 6.5 days, reduced by 74%. In addition, with the low-pressure technology, the product showed the best sensory quality with the yield reached 97%.

25 Quantitive Detection Method for Natural Resistant Starch

FAN Yuan-yuan , MA Qing , TAN Mei-qing , YANG Gong-ming

2013, 29(5):1036-1039.

[Abstract](1081) [HTML](0) [PDF 451.09 K](761)

Abstract:
Based on one-factor-at-a-time experiments, the main parameters influencing the quantitive detection of natural resistant starch were optimized by orthogonal test, including reaction time, pH value, reaction temperature, and saccharifying enzyme amount. For the remove of digestible starch, pH of mixed enzyme solution and water-incubation time were 6.0 and 12 h, respectively. For determination of resistant starch, the glucoamylase dosage, water-incubation temperature and time were 300 μL, 55 ℃ and 75 min, respectively.

26 Optimization of Extraction Process of Ginsenoside from Panax quinquefolius L. Collected from Canada by Response Surface Methodology

XU Yun-zhang , REN Ye , WANG Jing-xia , SUN Mei , ZHAO Xiao-yan , LIU Yuan

2013, 29(5):1040-1044.

[Abstract](1218) [HTML](0) [PDF 506.11 K](709)

Abstract:
The Response Surface Methodology (RSM) was used to optimize the extraction process of ginsenoside from P. quinquefolius L. collected from Canada. Based on one-factor-at-a-time experiments, extract yield of the ginsenoside-Rb1 was used as response for establishing a quadratic regression model. Temperature and time of extraction, ethanol concentration and liquid-to-solid ratio were selected as the factors for RSM design. The results showed that the best extraction conditions were as follows: extraction temperature 90 ℃, extraction time 1.88 h, ethanol concentration 77.4%, solid-liquid ratio 1:25, and extracted times twice, under which the predicted yield of ginsenoside-Rb1 with the optimized procedure was up to 1.40%and practical yield was 1.41%.

27 Production Technology of a Rice Wine with Frost Mulberry Leaves

TAN Hai-gang , LI Jing

2013, 29(5):1045-1047.

[Abstract](1035) [HTML](0) [PDF 456.57 K](943)

Abstract:
Mulberry leaves have good effect on health and can be used for both food and drug. The production technology of a rice wine with frost mulberry leaves was studied and the optimum producing conditions were as followed: the fermentative strain Mauri yeast, the steam pretreatment time 3 min, surface areas 0.02~0.08 cm2 and addition amount of frost mulberry leaves 0.01 g per g rice before fermentation. Under these conditions, the polyphenolic compounds contents, free amino acid contents and DPPH free radical scavenging rate of frost mulberry leaves rice wine was 0.11 mg/mL, 2.72 mg/mL and 92.26%, respectively. These results indicated that frost mulberry leaves rice wine possessed high nutritional value, had promising prospects for further development and thus might provide scientific basis on the exploitation of the abundant resources of mulberry leaves.

28 Enzyme Catalyzed Preparation of 1,3-Dioleoyl-2-palmitoylglycerol

JIANG Yu-yan , JI Zi , LIN Ying , ZHENG Shui-ping , HAN Shuang-yan

2013, 29(5):1048-1051.

[Abstract](1401) [HTML](0) [PDF 467.10 K](757)

Abstract:
1,3-Dioleoyl-2-palmitoylglycerol (OPO) is an important component of triglycerides in human milk fat. The research focused on the optimization of different reaction factors to produce 1,3-dioleoyl-2-palmitoylglycerol as human milk fat substitute catalyzed by the immobilized lipase RMIM with tripalmitin (PPP) and oleic acid (OA) as substrates. The optimum reaction conditions were as follows: the molar ratio of PPP and oleic acid 1:6, the enzyme dosage 8% of the weight of substrates, the reaction temperature 50 ℃ and the reaction time 6 h. In the products, the concentrations of oleic acid and palmitic acid in sn-2 position were 54.86% and 87.64%, respectively, of the total fatty acids.

29 Desalination of Macroporous Absorption Resin on Antioxidant Peptides from Tilapia Skin Collagen

XIA Guang-hua , SHEN Xuan-ri , JIU Zhi-qiang , HUANG Shuang-xia

2013, 29(5):1052-1056.

[Abstract](1001) [HTML](0) [PDF 492.67 K](779)

Abstract:
The desalting technology of antioxidant peptides from tilapia skin collagen by DA201-C macroporous adsorption resin was investigated. The results showed that the static absorption rate and absorbing capacity were 82.56% and 54mg/g, respectively. The best loading sample concentration, sampling flow rate and eluent were 60 mg/mL, 1 mL/min and 75% alcohol, respectively. Under these conditions, the desalination rate was 97.13% and recovery of peptides was 81.16%. The antioxidant activity was increased to 39.58% at the concentration of 0.245 mg/mL. In conclusion, it was available and effective to desalt the antioxidant peptides from tilapia skin collagen by using DA201-C macroporous absorption resin.

30 Effect of Polysaccharides from Seaweeds by Citric Acid Extraction in Cigarette Quality

CHEN Sen-lin , SHEN Guang-lin , ZHUO Hao-lian , LU Jiang-hong , CUI Chun , ZHAO Mou-ming

2013, 29(5):1057-1060.

[Abstract](988) [HTML](0) [PDF 460.33 K](714)

Abstract:
Polysaccharides from different algae species (Laminaria japonica, Porphyra, Sargassum fusiform, Eucheuma) were obtained by citric acid extraction. The best algae specie was determined by analysis of the extraction yield of polysaccharides and cigarette quality. The results showed that polysaccharides from Laminaria japonica could obviously improve the cigarette quality, especially sample Ⅰ and Ⅳ. By the sensory evaluation of the cigarette, the best dosage of polysaccharides was determined as 0.1%. Moreover, sample Ⅰand Ⅳ had some promotion effect on the smoothness, irritation and finish of smoking, but showed little effect on miscellaneous gases.

31 Extraction of Total Alkaloids from Mixed Herbs Yisuitongjing

ZHANG Jie , WANG Hua-yu , REN Yu , ZHANG Wei-yu

2013, 29(5):1061-1064.

[Abstract](840) [HTML](0) [PDF 442.88 K](708)

Abstract:
The extraction method and process for total alkaloids in a herb mixture named Yisuitongjing were optimized in this paper. With the content of total alkaloids as indexes, the extraction method was optimized by single factor experiment and the extraction process was optimized by orthogonal experiment. The highest extraction yield of total alkaloids were reached when using ethanol as reflux extraction regent and adding 50% ethanol solution for twelve times with extracting time 2.0 h. The extraction process was simple and reasonable, suitable for industrial production.

32 Optimizition of Microwave Assisted Extraction of Total Flavone from Sonchus oleraceus L.

QUAN Mei-ping

2013, 29(5):1065-1067.

[Abstract](970) [HTML](0) [PDF 451.69 K](668)

Abstract:
A new method for extracting total flavone from Sonchus oleraceus L. was developed by microwave assisted extraction and the flavone content was measured with NaNO2-Al(NO3)3 colorimetry. The effects of influencial factors on total flavone ethanol concentration were discussed and the parameters were optimized by means of single factor test and orthogonal designed experiments. Results showed that the impact order of the influence factors was extraction time>solid/liquid ratio>ethanol concentration. The obtained optimum conditions for total flavone extraction were ethanol concentration 40%, dealing time 8min and the ration of material to solvent 1:30. The flavone yield under the optimum conditions was 19.6 mg/g.

33 Extraction of Essential Oil from Meizhou Shatian Shaddock Peel by Subcritical Fluid

LI Mai , YANG Ji-guo , NING Zheng-xiang , LAN Qi-tian

2013, 29(5):1068-1071.

[Abstract](1120) [HTML](0) [PDF 440.02 K](726)

Abstract:
The possibility of extracting essential oil from the oiliness layer of Meizhou Shatian shaddock peel by subcritical fluid was discussed in this study. The results showed that when the extraction temperature, oiliness layer drying method, oiliness layer water content and extrcing times were 40 ℃, 60 ℃ hot air drying or natural drying, 8% and 2 , respectively, essential oil yield reached 2.36% by subcritical extraction technology with butane as medium. The shaddock peel essential oil was a yellow oil aromatic liquid with typical shaddock peel special flavour. GC-MS analysis showed that, the essential oil components mainly existed in the form of terpenes, in which D- limonene showed the highest content of 81.27%.

34 Development of a Bone-in Pickled Chicken Claw with Bubble Pepper

DOU Cheng-lin , WANG Qing , WU Zhen-ye , ZHOU Ji-xu

2013, 29(5):1072-1075.

[Abstract](1257) [HTML](0) [PDF 385.74 K](1004)

Abstract:
Effect of processing parameters for a bone-in pickled chicken claw with bubble pepper on the quality of products were studied in this paper.The results showed that the best cooking conditions (15 min, 90 ℃) was suitable for separation of the bone from chicken claw and maintaining the form of chicken claw. The order of the influence degree of the key parameters on the product sensory quality was: pickling time>pickling temperature>sample solution ratio. Orthogonal test showed the optimal processing conditions were pickling temperature 25 ℃, pickling time 12 h and sample solution ratio 0.6 kg/L. The best ingredients of birds meat bittern were (for every 100 kg chicken claw) 20 kg pod pepper, 3.5 kg salt, 10 kg sesame oil, 0.4 kg lactic acid, 0.6 kg Illicium verum, 2 kg sugar, 1 kg monosodium glutamate and 0.05 kg I+G, The product tasted slightly salty, hot and sour, with pure fragrance.

35 Screening of Salt-tolerant Yeast for Fermented Flavor Chopped Pepper

XU Hao , LIU Su-chun , NIE Rong , LIU Ying , LI Luo-ming , WANG Fei

2013, 29(5):1076-1079.

[Abstract](1078) [HTML](0) [PDF 655.24 K](748)

Abstract:
A salt-tolerant yeast, named Yx.509, was screened from the salty pepper blank, which can survive and tolerate 24% NaCl. The culture of strain was then scaled-up after inoculated the stain to highly salty chopped pepper blank. After 7days, the fermented chopped pepper showed a good flavor, bright red color and crisp feel. This strain was identified as Zygosaccharomyces rouxii by using morphological, physiological and biochemical tests and 26S rDNA sequencing.

36 Optimization of Immobilization Conditions for Protease and Its Application in the Fermentation of Soy Sauce

WU Hui-ling , WEI Lu-ning , ZHOU Zi-qi , YUAN Guo-xin , YAN Zhe , PAN Hai-peng , LIN Kang-yi , JIANG Xiao-bo , CHEN Yong-quan , HU Wen-feng

2013, 29(5):1080-1084.

[Abstract](934) [HTML](0) [PDF 409.67 K](770)

Abstract:
The aim of this research was to increase the protein conversion ratio and short the fermentation period of traditional Chinese soy sauce by using immobilization technics. The concentration of sodium alginate, calcium chloride, volume ratio of enzyme to carrier solution and immobilization time were selected as the factors to optimize the immobilization process of neutral protease powder, and the immobilized neutral protease powder was applied in the fermentation of high-salt liquid state soy sauce. The results indicated that the optimal immobilization process condition of immobilized gel particles with good stability and the highest relative enzyme activity were 0.007 M sodium alginate, 0.27 M calcium chloride, and the volume ratio of enzyme to carrier solution 12:30 after immobilizing for 2 hours. Contrast to the control group, the index contents of the dissociative and immobilized group added with 5.80 g neutral protease in 17.5 kg sauce mash were improved significantly during the fermentation process, and the fermentation period was shorten by about 20 days; and the protein conversion rate of the immobilized protease powder group was improved by about 6.08% and 1.88% respectively, compared to the control and dissociative enzyme group. It is concluded that the immobilized neutral protease powder could improve the protein conversion rate and shorten the fermentation period of the fermentation of high-salt liquid state soy sauce.

37 Processing Technology for a Soybean-protein Beverage Fermented by Lactobacillus

WANG Cai-hua , BI Hui-min , ZHOU Xue-song , ZENG Jian-xin

2013, 29(5):1085-1088.

[Abstract](1049) [HTML](0) [PDF 482.14 K](741)

Abstract:
Processing conditions for a soybean-protein drink with Lactobacillus were studied. Grinding parameters of soybean and enzymatic hydrolysis of soybean were optimized in order to improve flavor and number of active Lactobacillus during storage. Soybean was boiled in 0.05% citric acid solutions for 5 minutes, and then soaked in water at 37 ℃ for 4 hours. The soaked soybean was ground to soy milk and filtered. Filtrate of soy milk was hydrolyzed by 0.5% papain at 55 ℃ for 4 hours. .Hydrolyzed milk was heated to 90 ℃ for 10 minutes to inactivate papain, and then fermented by Lactobacillus. Lactobacillus drink containing soybean peptide based on the fermented soy milk tasted good and showed non-significant beany flavor. The number of active Lactobacillus in the beverage was above 108 cfu/mL after a 30-day storage.

38 Optimization of Enzymatic Hydrolysis of Polyrhachis vicina Roger Protein and Graded Membrane Separation of the Antioxidant Peptides

LING Meng-le , LIU Tong-xun

2013, 29(5):1089-1092.

[Abstract](1295) [HTML](0) [PDF 532.17 K](808)

Abstract:
The influences of hydrolysis time, pH, temperature, enzyme and time on enzymatic hydrolysis of Polyrhachis vicina Roger protein by alcalase 2.4L were investigated. The antioxidant activity of the product was evaluated by determining five indexes including the scavenging activities of superoxide radical, DPPH? and hydroxyl radical, reducing power and inhibitory ability against oxidation of linoleic acid. By response surface methodology (RSM), the hydrolysis conditions were optimized to achieve the highest antioxidant activity of the product. Verification experiments confirmed the accuracy of equations more than 95%. Ultrafiltration and chromatography techniques were performed to purify enzymatic hydrolysates. It was found that peptides in the range of 5~10 kDa and 1~3 kDa mainly accounted for the activity. Basic peptides had greater scavenging capacity against superoxide radical and hydroxyl radical, as well as inhibitory ability against oxidation of linoleic acid, than acidic peptides. Acidic peptides had higher DPPH? radical scavenging activities and reducing power compared with basic peptides.

39 Micro-wave Sterilization of Sanhuali Fruit Cake

XIAO Nan , HE Jian-mei , LI Ting , CHEN Yu , HUANG Miao-yun , LI Yuan-zhi

2013, 29(5):1093-1095.

[Abstract](1120) [HTML](0) [PDF 287.42 K](639)

Abstract:
The micro-wave sterilization process for the Sanhuali fruit cake was studied in this paper . Investigation of effects of microwave power, sterilization time and cake thickness on the index of the aerobic bacterial count and sensory evaluation showed that the optimum micro-wave power, sterilization time and cake thickness were 480 w, 50 s and 0.4 cm, respectively.

40 Extraction of Polysaccharides from Morinda officinalis How Residue

ZENG Xiao-qian , ZHANG Er-mei , PAN Kui-you , YANG Xiao-hong , CHEN Hua-xiao , SHAO Mei-yun , ZHANG Hua-lin

2013, 29(5):1096-1099.

[Abstract](1003) [HTML](0) [PDF 347.23 K](644)

Abstract:
In order to utilize the discarded residue, the extraction conditions for polysaccharides in the discarded residue of Morinda officinalis How were investigated. With the yield of polysaccharides as index, the effects of several factors such as temperature, time, ratio of solid to liquid and times on the extraction of polysaccharides from M. officinalis residue were invstigated using single factor analysis. On the base of the single factor analysis, the optimal the extraction conditions were obtained by orthogonal analysis. The results showed that temperature and times were the major factors which affecting the extraction of polysaccharides, time and ratio of solid to liquid were the secondary ones. The best conditions for extraction were: distilled water extraction time 1 h, temperature 100 ℃, ratio of solid to liquid 1:7 (m/V). and extracting times 2. Under these conditions, the yield of M. officinalis polysaccharides was 15.67%. The process was reproducible with high yield of polysaccharides.

41 Ultrasonic-assisted Extraction of Polysaccharides from Carambola Leaves

CHEN Wen-yan , LIN Yan-ru

2013, 29(5):1100-1102.

[Abstract](1175) [HTML](0) [PDF 397.45 K](737)

Abstract:
In this research, polysaccharides were extracted from carambola leaves by adopting the ultrasonic-assisted extraction technique. The influence of extraction times, solid-liquid ratio, temperature, ultrasonic power and radiation time on the extraction yield of carambola leaves polysaccharides was investigated. By using the orthogonal array L9(34), the optimum extraction conditions of carambola leaves polysaccharides were determined as: solid-liquid ratio 1:50, temperature 65 ℃, ultrasonic power 450 W and radiation time 35 min, under which the extraction yield of carambola leaves polysaccharides reached 18.89 mg/g.

42 Application of White Vinegar in Preparation of Chiffon Cake

ZENG Li-fen

2013, 29(5):1103-1105.

[Abstract](1466) [HTML](0) [PDF 319.31 K](998)

Abstract:
White vinegar is a water-soluble transparent acid. It can neutralize the basicity of egg white, to stabilize egg white and get more volume when whipping. So it can be used as a substitute of Tartar powder in the production of Chiffon cake. Egg white can form steady bubbles under pH 4.6~4.8, which was applied to prepare Chiffon cake. In this paper, the effects of vinegar amount on physicochemical properties and sensory quality of the as-prepared Chiffon cake were studied The best amount of white vinegar was determined as 6.0%.

43 Development of a Whole Pomelo Juice Beverage

YAO Zhuang-he , ZHANG Li-yan , RUI Han-ming

2013, 29(5):1106-1109.

[Abstract](1202) [HTML](0) [PDF 460.64 K](682)

Abstract:
The key technologies for development of a pomelo juice bevereage were investigated in this paper, including flavor formula, stabilizer formula and homogenization conditions. The results showed that the optimum formula of the pomelo juice beverage was 8% whole pomelo juice, 10% sugar, 0.06% citric acid, xanthan gum 0.05%, CMC 0.16% and agar 0.06%. The pomelo juice beverage mixed was homogenized for three times under the pressure of 20 MPa at about 40 ℃. The microparticles in the pomelo juice beverage were well-distributed and not easy to agglomerate. The beverage had good stability after sterilization and showed a sweet and sour taste, a rich pomelo flavor and a lighter bitterness. And the product showed better physicochemical indices when prepared under optimum conditions..

44 Safety and Toxicology Evaluation of an Alleviate Eyestrain Wolfberry Beverage

CHEN Wei-lin , HUANG Rong , LIU Dun-hua

2013, 29(5):1112-1118.

[Abstract](1057) [HTML](0) [PDF 668.47 K](715)

Abstract:
Through acute toxicity test, genetic toxicity test, traditional teratogenic test and 30-day feeding test, the wolfberry beverage was confirmed as safe and non-toxic. Preliminary evaluation of its alleviate eyestrain effect on human showed that the visual fatigue symptoms of 66.67% of the subjects were obviously alleviated. The bright durability of their eyes was improved by an average of 17.15 ±8.37% and the distant vision was improved by 0.14 ± 0.07%. Statistical analysis showed a significant difference in the results.

45 Comparison of Nutrition Composition and Antioxidant Activity of Several Brown Rice

ZHANG Wen-hao , DENG Yuan-yuan , WEI Zhen-cheng

2013, 29(5):1119-1122.

[Abstract](1673) [HTML](0) [PDF 415.77 K](1002)

Abstract:
The main nutritional components of protein, crude fat, vitamins and minerals were compared and analyzed in four different rices , which were germinated semi-brown rice, brown rice, semin-brown rice and milled rice. Meanwhile, the content and total antioxidant capacity of active components of total phenolics, total flavonoids and monomeric phenolic contents were investigated. The results show that the contents of VE, total phenolics and flavonoids, coumalic acid and ferulic acid and their total antioxidant capacity of germinated semi-brown rice are 40% to 100% higher than those in brown rice , 60~130 % higher than semi-brown rice and 120~440 % higher than milled rice. The contents of VA, VB1, VB2和VE in germinated semi-brown rice are increased 3 to 15 times than those of milled rice.. And the contents of total phenolics, flavonoids, coumalic acid and ferulic acid and their total antioxidant capacity are 1 to 4 times higher,than those of milled rice. Moreover, the contents of protein, crude fat, and minerals content are 30~290% higher in geminated semi-brown rice than those of milled rice. From those, it can be seen that the geminated semi-brown rice is a kind whole grain food .with high nutrition value.

46 Rapid Determination of Organic Acids and Vitamin in Ju’lu Apricot by a Multi-wavelength Analysis

LIU Zheng-hao , SU Yao-hui , MU Shuang , PANG Yan-ping , LI Pei-shan , WEI Cong-cong

2013, 29(5):1123-1127.

[Abstract](918) [HTML](0) [PDF 586.40 K](759)

Abstract:
High performance liquid chromatography (HPLC) with diode array detector (DAD) was applied to determine water-soluble organic acids (malic acid, citric acid and succinic acid) and vitamins (Vc, VB1 and VB2) in apricots sampled from Julu. The apricots samples were eluted using 0.5 mmol/L H3PO4 -acetonitrile as mobile phase at several wavelengths (210 nm, 254 nm and 270 nm) . The substances can be efficiently separated in 13 min with RSD value ranged in 0.75~2.12%. The precisions were between 0.94% and 1.55% and the result of recoveries was of 96.70~101.9%. The difference in organic acid and vitamin contents between Julu apricot and those sampled from other sources were also compared.

47 Determination of Uridine, Guanosine and Adenosine Contents in Allium Macrostemon Bunge by RP-HPLC

LIU Hong , CHEN Yan-qin , DENG Feng , JIA Jiao

2013, 29(5):1128-1130.

[Abstract](1259) [HTML](0) [PDF 425.11 K](749)

Abstract:
A new method for determination of uridine, guanosine and adenosine contents in Allium macrostemon bunge were established by using RP-HPLC gradient elution. The extracts were separated on a ZORBAX-SB-C18 analytical column (4.60 mm×250 mm, 5 μm) with CH3OH-H2O as mobile phase at 260 nm. The flow rate was 0.6 mL?min- 1and the column temperature was 25 ℃. The linear ranges of uridine,guanosine and adenosine were 0.0784~0.784 μg（r=0.9995）, 0.0798~0.798 μg（r=0.9995）and 0.0852~0.852 μg (r=0.9994), respectively. This method showed high reproducibility and can be used for quality control of the Allium macrostemon bunge.

48 Real-time Isothermal Detection of Vibrio parahaemolyticus by ESEQuant Tube Scanner

YI Min-ying , LING Li , LIU Zhu-hong , YE Lei , TANG Da-yun , SHI Lei

2013, 29(5):1131-1135.

[Abstract](1728) [HTML](0) [PDF 475.31 K](616)

Abstract:
In order to detect the Vibrio parahaemolyticus in the import and export foods more accurately and quickly, the study designed the loop-mediated isothermal amplification (LAMP) primer sets targeted the tlh gene of V. parahaemolyticus, and detected the LAMP results real-time by the ESEQuant tube scanner. The results showed that the reaction characterized with high efficiency, high specificity and high sensitivity (1~10 CFU/reaction, about 100 times than the real-time PCR). One hundred and twenty-six out of 126 V. parahaemolyticus strains were detedted as Vibrio parahaemolyticus by the LAMP assay with the ESEQuant tube scanner, while 121 strains were detected as V. parahaemolyticus by the real-time PCR. The ESEQuant tube scanner is comparable to the real-time PCR machine in the sense that both are capable of detecting samples in real-time resulting and both are capable of conducting melting curve analysis, which means the ESEQuant tube scanner system can both served as research application in basic laboratory or offering pre-treatment diagnosis in primary health care settings in developing areas.

49 Determination of 56 Pesticides in Black Tea by GC-MS/MS with Timed SRM

CHEN Li-wei , WANG Bin , LIU Chun-sheng , LUO Dong-hui , CHEN Yi-guang , HAN Wan-qing

2013, 29(5):1136-1143.

[Abstract](1089) [HTML](0) [PDF 704.44 K](815)

Abstract:
A novel method was developed for simultaneous determination of methamidophos and other 55 pesticides in black tea using gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The extraction effects of different extraction regents were compared and the purifying effects of Cleanert TPT Solid phase extraction column and QuEChERS were also investigated. The optimum pretreatment conditions for the tea samples were determined as follows: extracting the tea samples by n-hexane: acetone (7:3, V/V) followed by Cleanert TPT column purification. After purified by Cleanert TPT solid-phase extraction tube, the signal-noise ratios of 54 pesticides were improved by two times. The purified samples were then analyzed by GC-MS/MS with “timed SRM” mode, and quantified by internal standard method. Timed SRM can solve the data shortage and quantitative accuracy problem caused by traditional MRM method. The limits of detection were in the range of 1 μg/kg to 18 μg/kg. At the spiked levels of 3 μg/kg to 600 μg/kg, the recoveries of 55 pesticides (except methamidophos)ranged from 73% to 126% with the relative standard deviation less than 18% (n=6). The results demonstrated that this method was accurate and effective, suitable for the determination of 56 pesticides residues in black tea.

50 Determination of the Change of OTA in Luzhou-flavor Liquor Production by Enzyme-linked Immunosorbent Assay (ELISA)

YE Guang-bin , LUO Hui-bo , YANG Xiao-dong , LI Dan-yu , SHEN Cai-ping

2013, 29(5):1144-1147.

[Abstract](1021) [HTML](0) [PDF 461.53 K](631)

Abstract:
In this study, Ochratoxin A (OTA) in Luzhou Daqu, pit entry fermented grains, waste lees, yellow water, base liquor, wine products were detected with ELISA kit. The results showed that the detection sensitivity, the relative standard deviation (RSD) in 5 parallel determinations and the average spike recovery rate were 0.3μg/kg,1.497~3.369% and 96.4%, respectively. OTA content of all samples were well below the domestic and overseas food industry standards, indicating that the preliminary results indicate that OTA in Luzhou-flavor liquor production was safe.

51 Determination of Dicyandiamide in Milk Powder Samples by QuEChERS-Ultra-HPLC-Tandem MS

LUO Hai-ying , XIAN Yan-ping , HOU Xiang-chang , WU Wen-hai , WU Yu-luan , GUO Xin-dong , WANG Li

2013, 29(5):1148-1153.

[Abstract](1232) [HTML](0) [PDF 629.73 K](696)

Abstract:
A new method was established to determine Dicyandiamide in milk powder samples by QuEChERS cleanup combined with ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The sample was dissolved and extracted in hot water through ultrasonic wave, and protein was precipitated in acetonitrile. Then the extracted solution was purified by N-hexane and QuEChERS, and analyzed using UPLC-MS/MS. Dicyandiamide was identified by retention time and the ratio of the characteristic ions, and quantitatived with external standard method. In the study, the test situation and matrix effects of different samples matrix, including skimmed milk powder, whole milk powder, formula milk powder, acid milk powder and whey powder, were investigated. The result showed that the method quantitation limit (S/N=10) of dicyandiamide were 25 μg/kg in sample of formula milk powder and 12 μg/kg in the rest 4 kinds of sample. The average recoveries were between 88.6% and 111% at spiked levels of 12 - 250 μg/kg, the precision (n=6) ranged from 3.1% to 8.2%. The inter-day RSDs (n=5) were between 3.7% and 9.4%. Among 25 samples analyzed, only 2 samples were positive. The method was simple, sensitive, and accurate for the determination of dicyandiamide in milk powder samples.

52 Rapid Detection of Clenbuterol Content in Pig Urine by Immunofluorescence Chromatography

GUO Shi-jing , TANG Hai-bo , QI Wei

2013, 29(5):1154-1156.

[Abstract](1128) [HTML](0) [PDF 407.71 K](695)

Abstract:
Quantitative detection of the clenbuterol in pig urine was investigated with a clenbuterol kit based on immunofluorescence chromatography and a fluorescence quantitative detector. The detection limit was up to 0.26 μg/L and the cross-reaction with the chemical drugs of similar structure was less than 0.20%. And the experiment confirmed that the kit had 1-year shelf life. The total detection process just takes about 20 minutes.

53 GC-MS Analysis of the Volatile Components of Mulberry Leaf Tea

LIANG Gui-qiu , LI Quan , LU Fei , ZHOU Xiao-ling , WU Jing-jing , LU Chun-xia

2013, 29(5):1157-1159.

[Abstract](1294) [HTML](0) [PDF 440.70 K](759)

Abstract:
Volatile components in mulberry leaf tea were extracted by headspace solid phase micro extraction method using gas chromatography-mass spectrometry (GC-MS) technique. NIST 05 spectrum-search showed that 42 volatile compounds existed in mulberry leaf tea, including 10 aldehydes, 9 ketones 4 alcohols, 3 esters, 2 acides, 10 alkanes and 4 other compounds. Among the volatile compounds, aldehydes and ketones showed high contents, being of 24.67% and 22.36%, respectively.

54 Rapid Identification of Cheng’an Strawberry with Near Infrared Spectroscopy

PANG Yan-ping , LIU Kun , YAN Jun-ying , LI Pei-shan

2013, 29(5):1160-1162.

[Abstract](1286) [HTML](0) [PDF 523.97 K](795)

Abstract:
In order to determine the authenticity of Cheng’an strawberry, near infrared spectra of sample from different areas were adopted in the study. Near infrared spectra were pretreated with second derivate, first derivate, SNV and 5 points moving-smooth to set up a model of identification of samples based on factor analysis qualification testing and principal component analysis (PCA). The results showed that the identifying rate of Cheng’an strawberry from different area samples tested by three models on the basis of pattern recognition was greater than 93.3%. In conclusion, near-infrared spectroscopy pattern recognition technology had significant potential as a rapid and accurate method for identification of Cheng’an strawberry.

55 ICP-MS Determination of 8 Kinds of Trace Element in Mussel and Bighead Tissue

HONG Bo , WANG Dong-wu , WU Yuan-an , LIU Lin-li , CHEN Xiang-yi , LIU Ming-qiu , LIU Li

2013, 29(5):1163-1165.

[Abstract](1005) [HTML](0) [PDF 438.17 K](759)

Abstract:
A method of microwave digestion-ICP/MS was established to determinate 8 kinds of trace element in mussel and bighead tissue. The sample was added with HNO3+H2O2 (3+1) after microwave digestion before ICP-MS determination. The introduction of Ge, In, Bi, Sc as internal standard substance can avoid spectral interferences, and the parameters of the apparatus was optimized. The detection limits of Fe, Cu, Zn, Mn, Cd, Pb, As and Hg were 2.3, 0.5, 1.1, 0.4, 0.6, 0.5, 1 and 1.8 μg/L, respectively, with the correlation coefficient higher than 0.9993. The recovery rate and relative standard deviation were 80.4~101.2% and less than 6.29%, respectively. The analysis of Lamprotula leai samples showed that Lamprotula leai was rich in Fe, Zn. However, several potentially harmful elements, such as Pb, Cd and Hg were also exist in the samples.

56 Determination of Sorbic Acid and Benzoic Acid in Foods Using Multi-sample Simultaneous Extraction-gas Chromatography

ZHU Guo-qiang , WEI Li-li , JIANG En-yuan

2013, 29(5):1166-1169.

[Abstract](1003) [HTML](0) [PDF 452.99 K](739)

Abstract:
A novel method for determination of sorbic acid and benzoic acid in food was developed using multi-sample simultaneous extraction-gas chromatography. The samples and standard series solution were extracted simultaneously, with a mixture of ethyl acetate and hexane (1+1) as extraction solvent. The contents of sorbic acid and benzoic acid were measured by SE-30 wide caliber capillary. In the selected conditions, the detection limit for sorbic acid and benzoic acid was 1 mg/kg, the linear range was 25~500 mg/kg, the recoveries was 93.2~102.4% and the RSD was 1.9~4.1%. The method was simple, rapid, easy control and low-cost. It can be used for the rapid quantitative analysis of batch sample.

57 Determination of 16 Mineral Elements in Walnut by Total Reflection X-ray Fluorescence with Constant Pressure Digestion

LI Meng

2013, 29(5):1170-1172.

[Abstract](1103) [HTML](0) [PDF 475.06 K](613)

Abstract:
A method for the determination of 16 mineral elements, such as K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr and Pb in walnut was developed by total reflection X-ray fluorescence (TXRF) with constant pressure digestion. The optimized temperature and time of the constant pressure digestion were 180 ℃ and 4 h, respectively. The certified reference material (CRM, GBW10026) was digested and determined. And the lower limit of detection (LLD) and the limit of determination (LDM) of different element in walnut were calculated. calculated to be 0.001~0.045 mg/L and 0.003~0.144 mg/kg, respectively. TXRF analytical results showed that the 16 mineral elements in the CRM consistent were within the standard value ranges. This method showed advantages in lower cost of the pretreatment equipment, easy operation, less sample consumption and low detection limit. The contents of 16 mineral elements in walnut determined by this method showed little difference with the results by ICP-MS. The relative standard deviations (RSD) of TXRF were lower than 3.9%.

58 Analysis of Characteristic Aroma Compounds of Ningxia Tan Mutton

LI Wei , LUO Rui-ming , LI Ya-lei , YANG Bo

2013, 29(5):1173-1177.

[Abstract](1135) [HTML](0) [PDF 472.62 K](775)

Abstract:
To research characteristic aroma compounds of Ningxia Tan mutton, the volatile compounds in the mutton was extracted by headspace solid-phase microextraction (HS-SPME), and analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). The optimum pre-extraction conditions for mutton samples were determined as 75 μm CAR/PDMS, 60 ℃ and 30min. Totally 43 volatile flavor compounds were then identified by GC-MS and GC-O, including 5 hydrocarbons, 12 aldehydes, 5 ketones, 6 alcohols, 6 acids, 7 ester and 2 cyclo-compounds. Among these volatile flavor compounds, hexanal, heptanal, hexanoic acid-ethyl ester, nonanal, 1-nonanol and tetradecanoic acid made a greater contribution to the flavor of Ningxia Tan mutton.

59 Application of Conductivity Evaluate Pork Freshness

YANG Xiu-juan , ZHANG Xi , ZHAO Jin-yan , WANG Guan-ji , Xiao Yang , TAO Lin-li

2013, 29(5):1178-1180.

[Abstract](1277) [HTML](0) [PDF 443.58 K](875)

Abstract:
35 loin muscle samples were collected from market at random, in order to research the variation and relationship between TVB-N and conductivity of fresh pork in the corruption process. The results showed that the porkwas kept at the temperature of 30 ℃ and humidity of 85% for 3 days, TVB-N and conductivity were gradually increased with the corruption of pork.In different time periods, correlation test between conductivity and TVB-N value were of highly significant (P<0.01) with the correlation coefficient being of 0.926. Conductivity and TVB-N presented a linear regression relationship and the regression equation was y=50.582x-54.452 (P<0.01). The coefficient of determination was 0.857 and conductivity value was ≤1.37 mS/cm. Therefore the pork can be assessed as fresh pork.

60 Research Progress and Industrial Utilization of Antarctic Krill in China

SHEN Xiao-sheng , HAN Xiao-long , ZHANG Hai-yan , CAI You-qiong , CHEN Xue-zhong

2013, 29(5):1181-1184.

[Abstract](1691) [HTML](0) [PDF 486.83 K](1164)

Abstract:
In this review, the resources investigations, fishing situation, processing and industrial utilization situation of antarctic krill were discussed in order to highlight the recognition degree of antarctic krill resources and promote the rapid development of antarctic krill industry.

61 Application of Microalgal Bioactives in Food Industry

WANG Dong-qin , TAN Yu , LU Hong-yu , SU Wei-ming , HU Xue-qiong , LI Yan-qun

2013, 29(5):1185-1191.

[Abstract](1367) [HTML](0) [PDF 520.59 K](817)

Abstract:
Microalgae can produce many bioactives, some of which can be used as ingredients of functional food. Some microalgae can accumulate large amount of long-chain unsaturated fatty acids, including arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are very important for human. Except for DHA, other very long chain unsaturated fatty acids have not be commercially produced by microalgae. Microalgae synthesize polysaccharides as their cell structural components, energy storage materials or other physiological molecules. Some polysaccharides also have bioactivities for human health. Microalgal polysaccharides usually can give a good viscoelastic rheological property which is benefit in some function foods, such as jells and drinks. Pigments, including carotenoids, phycobiliproteins and chlorophylls, are good food colorants with bioactivities. Some carotenoids pigments have been commercially developed, but others, including chlorophylls, are waiting for well development. Microalgae synthesize many kinds of peptides, some of which have bioactivities such as antivirus, angiotensin converting enzyme inhibitory activity and antioxidative activity. Some bioactive peptides can also be produced through hydrolisation of microalgal proteins. This paper reviewed the health-promoting properties of microalgal bioactives and their applications in functional food ingredients of the microalgal actives.

62 Research Progress of Influence of Phenolic Compounds on Color of Grape Wine

HAO Xiao-yun , WANG Hong , ZHANG Jun-xiang

2013, 29(5):1192-1197.

[Abstract](1229) [HTML](0) [PDF 478.94 K](734)

Abstract:
Color was generally considered as an important sensory quality index of red wine,reflecting the quality , type and storage stability. It also was an important factor influencing consumers in purchasing wine. Phenolic compounds was one of the key components in red wine, playing an important role in the formation of wine flavor, taste and color. In this paper, the phenolic compounds in red wine were systematicaly summarized and discussed.

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Volume 29,Issue 5,2013 Table of Contents