Abstract:The brain protective effect of Lilium lancifolium hypericin on the hippocampal tissue of the rats with cerebral ischemia reperfusion injury was investigated. The 50 male SD rats were randomly divided into sham group (S), model group (M), hypericin low (25 mg/kg), middle (50 mg/kg) and high (100 mg/kg) dose groups in this work. Except S group, other groups were given the modified Longa line blockage method to establish the left middle cerebral artery occlusion (MCAO) model. After 24 hours of modeling, the learning and memory ability of rats were tested by Morris water test, and brain tissue was taken for pathological HE staining to evaluate the damage of neurons in the hippocampus. Western-blot was employed to detect the expression of BDNF and p75NTR in hippocampus. The results showed that high-dose hypericin could significantly shorten the escape latency times (15.45±1.86) and increase the number of crossing the platform (8.67±1.52) times for the ischemia-reperfusion rats, which was statistically different from that in the M group (p<0.05). In addition, the pathological damage in the hippocampal area was improved, so that the nerve cells were arranged orderly, with clear structure and basically intact and normal morphology. It can also regulate the increase of BDNF expression and the decrease of p75NRT lever in hippocampal tissue (p<0.05). Hypericin can significantly improve the cognitive impairment caused by ischemia reperfusion injury and improve the learning and memory ability. Moreover, it has a certain brain protective effect, which might be caused by the up-regulation of BDNF and down-regulation of p75NRT expressions to reduce the damage of neurons and neurons in the hippocampus.

Abstract:The possible effects of β-Casomorphin-7 on renal function in aged mice were investigated. Fifty male Kunming mice were treated with 0.90% saline and low, moderate and high doses of β-Casomorphin-7. After continuous intragastric administration for 30 days, serum and tissue samples of all mice were collected for testing. Histopathological studies showed that β-Casomorphin-7 had a certain improvement effect on kidney tissue aging in aged mice. However, it seemed that the renal edema swelling in the high dose group was not alleviated and the epithelial cells were necrotic shedding. Compared with the model group, serum creatinine (CRE) levels, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase in the middle dose group of mice (GPx) activity were increased by 22.16%, 69.02%, 71.26% (p<0.05) and 24.41%, respectively, while the corresponding values in the high dose group were increased by 13.12%, 64.88%, 67.33% (p<0.05) and 17.90%, respectively. These suggested that β-Casomorphin-7 can regulate renal function and increase its antioxidant capacity in aged mice, but it is not dose-dependent. In addition, compared with the model group, the MDA levels of the mice treated with the low and moderate doses of β-Casomorphin-7 were decreased respectively by 15.40% and 3.17%, but increased by 16.08% in high-dose group. It indicated that the oxidation of the kidneys in the high-dose group of mice was aggravated. The results suggest that β-Casomorphin-7 may improve the renal dysfunction in aged mice. It may improve the aging damage by improving the antioxidant capacity. However, it seems to increase the kidney burden and cause other disease with the excessive intake of β-Casomorphin-7.

Abstract:Blue light (BL) had been employed in medicine recently to inactivate bacteria, while its mechanism needed to be investigated. Thus, this work conducted herein examined the bactericidal effect of BL on the food borne pathogen Cronobacter sakazakii, and the underlying mechanism. The results showed that BL above 30 J/cm2 exhibited an efficient bactericidal effect against C. sakazakii, and an inactivation rate above 8 log10 CFU was achieved under 240 J/cm2. Under the sublethal BL dose, singlet oxygen (1O2) and reactive oxygen species (ROS) were rapidly produced and gradually increased, followed by the emergence of malondialdehyde (MDA), indicating lipid oxidation in cells. Moreover, the permeability of the outer membrane of cell increased by 48.96% at 30 J/cm2, indicating injury to cell membranes. Results of fatty acid spectra showed that the contents of unsaturated fatty acids C18:2, C16:1 and C18:1 decreased and disappeared. This work confirmed at the first time the dynamic change of intracellular 1O2、ROS and MDA, and especially, revealed that damage on cell outer membrane was one the inactivation means of BL, because bacterial lipids, especially unsaturated fatty acids, are important targets for BL. These results will contribute to the study of the mechanism of blue-light sterilization.

Abstract:The antialcoholism effects and liver protection of Rosa roxburghii Tratt oral liquid in acute drunkenness mice were investigated. Anti-alcoholic experiment: Each group was established as an acute drunkenness model after all mice were administered corresponding samples for 30 days. After 1 hour, the blood and liver tissue were taken. Compared with the serum ethanol concentration, the levels of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in liver issues in different groups of mice; Liver protection experiment: The blood and liver tissue were taken after modeling. The liver index, the contents of superoxide dismutase (SOD) and glutathione (GSH) in the liver, and serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were determined. The results showed that compared with the model group, the high-dose group of Rosa roxburghii Tratt baverage decreased the serum ethanol concentration by 33.54%. It also increased the levels of ADH and ALDH, from 26.92 U/mL to 41.78 U/mL and 118.12 U/mL to 146.72 U/mL, respectively. The serum ALT and AST contents decreased by 58.40% and 42.69%, respectively, the liver index reduced by 9.80%, and the SOD content in liver issue increased by 72.65%, the GSH content increased by 25.34% (p<0.05). It indicates that Rosa roxburghii Tratt oral liquid has the function of relieving alcohol and has obvious protective effect on acute alcohol-induced hepatic injury.

Abstract:The effect of the enzymatic extraction treatment coupled with microfluidization on structure and physicochemical properties of tilapia skin collagen was investigated. Synergistic modification of three different kinds of enzymes and microfluidization was used in fish skin collagen, and their texture characteristics, rheological properties and microstructure were studied and compared in this study. The results showed that the diameter of collagen particles became smaller and more uniform, and the viscosity increased. The network structure of collagen was densely uniform, the gel strength, hardness, gumminess of collagen were increased by 75.17% and 14.44%, 27.26% and 77.66%, 67.87% and 8.90% after microstructure-Trypsin and microstructure-Pepsin, respectively. The network structure of collagen was loose and non-uniform, the gel strength, hardness, gumminess of collagen were decreased by 21.06%, 35.96%, and 28.28%, respectively. The sensory scores of fish skin collagen of microstructure-Pepsin treatment were highest in the sensory experiment, and more easily accepted by people. The results benefit to the utilization of by-product of Tilapia industry.

Abstract:The mechanism for dandelion extract to improve rheumatoid arthritis in rats was studied. The model of rheumatoid arthritis was established. Relevant indexes of therapeutic effect, pathological observation, and levels of interleukin-17 (IL-17), interleukin-23 (IL-23), interleukin-1 (IL-1), hsCRP, interleukin-1β (IL-β), and Tumor necrosis factor-α (TNF-α) osteoprotegerin (OPG), nuclear factor KB ligand receptor activator (RANKL, RANK) were investigated. Results showed that the swelling degree of the plantar paw in high dose of dandelion group (6.42±1.06) was lower than that in the model group (15.18±2.65) (p<0.05), the torsion (9.0±2.0) and foot contraction (8.5±1.5) were higher than those in model group (2.2±0.4 and 2.4±0.5, respectively). The levels of IL-17, IL-23, IL-1, hsCRP, IL-1β, TNF-α in high dose of dandelion group were lower than those in model group (p<0.01). The expressions of OPG (0.42±0.06), RANKL (0.52±0.08), RANK protein (0.45±0.05) in high dose of dandelion group were lower than those in model group (1.18±0.15, 1.35±0.46, 1.23±0.45, respectively) (p<0.01). The results indicated that taraxacum extract could inhibit the expression of inflammatory cytokines by regulating OPG/RANKL/RANK signaling pathway, and has a therapeutic effect on rheumatoid arthritis in rats.

Abstract:The present study collected 8 samples from aquaculture ponds for performing enrichment, isolation, purification and identification of bacteria strain scapable of removing NO2--N, NO3--N and NH4+-N. We obtained 8, 8 and 11 bacteria strains which could remove NO2--N, NO3--N and NH4+-N, respectively. These bacteria were classified into the genera Pseudomonas, Paracoccus, Zobellella, Achromobacter, Bosea, Paenarthrobacter, Corynebacterium, Bacillus, Delftia and Gordonia. After analysis of denitrification characteristics, two heterotrophic nitrification and aerobic denitrification bacteria strains with excellent denitrification effects were obtained and identified as Pseudomonas stutzeri j-1 and Zobellella denitrificans 2G-5, respectively. After incubated in 3 nitrogen media for 18 hours, the removal rates of NO2--N, NO3--N and NH4+-N by strain j-1 and 2G-5 were ranged from 99.53% to 99.89%. When applied in non-sterile aquaculture water, strain j-1 was successfully colonized and showed efficient denitrification. Whereas, strain 2G-5 didn’t proliferate well and its denitrification effect was unremarkable. This study exploited a collection of denitrification bacteria, obtained two heterotrophic nitrification and aerobic denitrification strains with important application potential, and provided biological materials for further study on bacterial mechanisms of nitrogen circulation and metabolism, and on research and development of denitrification techniques.

Abstract:To investigate the effects of calcium lactate treatment on postharvest physiology and biochemistry of blueberry fruits. The postharvest blueberries were immersed in a calcium lactate aqueous solution (10 g/L or 20 g/L) and deionized water (the control), respectively, for 10 min before being stored at 4 ℃. The related indicators were measured at day 0, 14, 28, 42, 56, and 70 over storage. The results showed that the calcium lactate treatment was beneficial to maintain the postharvest quality of blueberry fruits during the storage, through delaying the decrease of fruit firmness, the contents of total soluble solids (TSS), total phenols and flavonoids. on day 28, the firmness of the fruits treated with 20 g/L calcium lactate was 2.1 times as high as that of the control, and at the end of storage, the TSS of the fruits treated with 20 g/L calcium lactate treatment was 1.875 and 1.4 times, respectively, as high as those of the control and the 10 g/L treatment group, with the contents of total phenols, flavonoids and anthocyanins increased by 31.25%, 22.58% and 122.78%, respectively, compared with day 0. In addition, the treatments with 20 g/L calcium lactate led to reduced respiration rate and weight loss rate, constant anthocyanin content, and decreased activities of cellulase (Cs), polyphenol oxidase (PPO) and peroxidase (POD). The control had a peak PPO activity that was 1.56 and 2.12 times, respectively, as high as those for the 10 g/L and 20 g/L calcium lactate treatments, with increased superoxide dismutase (SOD) activity and total antioxidant capacity. The results showed that a calcium lactate treatment had a positive effect on postharvest preservation of blueberry fruits, with the treatment using calcium lactate at 20 g/L more desirable to maintain the postharvest quality of blueberries.

Abstract:In this paper, using water dropwort as material, the effects of superfine grinding time on the particle size distribution, morphology, the dissolutions of dietary fiber, flavonoids, total polyphenols, and color, functional and flow properties of water dropwort powder were investigated by comparing with the traditional coarse grinding. Moreover, the dissolution characteristics of phytochemicals in water dropwort powder with different particle sizes were measured and compared. Then, the DPPH radical scavenging activity, hydroxyl radical scavenging activity, ABTS radical scavenging activity, total reducing power and oxygen radical absorbance capacity (ORAC) assays were evaluated. The results showed that with the prolongation of superfine grinding time, the particle size of water dropwort powder decreased to 42.19 μm, the specific surface area increased to 0.28 m2/g, the dissolution of soluble dietary fiber increased to 7.26%, and the dissolutions of flavonoids and total polyphenols obviously increased. Meanwhile, superfine grinding enhanced the brightness and greenness, improved its solubility, water holding capacity and swelling capacity, but slightly reduced its fluidity. In addition, superfine grinding greatly improved the dissolution rate of flavonoids, total polyphenols, soluble proteins and polysaccharides, and also enhanced the DPPH, hydroxyl, ABTS radical scavenging activity, total reducing power, and oxygen radical absorbance capacity.

Abstract:The effects of nitric oxide (NO) fumigation and humidity on chilling tolerance of muskmelon fruit during postharvest storage were investigated. The muskmelon fruit was fumigated with 60 μL/L nitric oxide gas for 2 hours, along with air treatment as control, in three different humidity groups: Low humidity (LH: 35%~45%), medium humidity (MH: 65%~75%) and high humidity (HH: 90%~99%), respectively. The chilling injury and quality deterioration were all delayed by NO in all humidity groups. The chilling tolerance was improved significantly when the low humidity factor was 35%~45%. Compared with the control, the chilling injury of NO treatment group was delayed for 5 days, and the cold injury index was the lowest when it was stored for 30 days, only 40.00%; During the storage period, the fruit quality of the NO group was the best, and the slowest decline in the hardness was found (17.07 N), which was only 29.08% lower than the control group. The slowest growth in the cell membrane permeability was found (only 24.11%). It can Maintain fruit firmness and slow the increase in cell membrane permeability; It can effectively delay the decline of titratable acid and Vc content in fruit quality and maintain high soluble solid content. NO treatment can reduce the respiratory rate and ethylene release, while the peak of respiratory and ethylene peak delays, and the peak value is the lowest (33.80% and 27.04% lower than the control), respiration rate and the process of softening. It was confirmed that humidity was a factor affected the NO fumigation effect. These results suggested that the chilling tolerance improvement and the fruit quality enhancement of postharvest melon mightbe attributed to the low humidity and NO fumigation.

Abstract:To study the mechanism of Gastrodia elata extract on anti-hypoxia ability in rats. The rats were randomly divided into normal group, positive control group, low-dose Gastrodia elata extract group and high-dose Gastrodia elata extract group. The body weight, survival time and survival rate of rats were investigated. Malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), catalase (CAT), lactate dehydrogenase (LDH), lactate (LA), glutathione (GSH), glutathione reductase (GR), heat shock protein 70 (HSp70), endothelin-1 (ET-1), nitric oxide synthase (iNOS), the expression of related proteins for hypoxia inducible factor-1alpha (HIF-1a) were detected. The results showed that, compared with the normal group, the survival time of rats in the high dose Gastrodia elata extract group increased by 34.01%, the levels of LDH (8614.24 nmol/mL), LA (2.01 nmol/mL), GSH (965.5 mg/mL), GR (0.30 U/mL) increased (p<0.05), HSp70 (4.14), MDA (63.52 U/mL), CAT (23.24 U/mL), ET-1 (1.96), iNOS (2.10), HIF-1a (0.28) decreased (p<0.05). These results suggested that Gastrodia elata extract can effectively improve the antioxidant capacity of rats, the level of oxidative stress in rats, and thus improve the hypoxic capacity of rats.

Abstract:In this paper, the GC-MS analysis of volatile oil from Artemisia argyi and its antioxidant activity in mice were studied. The volatile oil in Artemisia argyi was extracted by steam distillation, and the volatile oil of Artemisia argyi was analyzed by GC-MS. The results showed that eight components were identified from Artemisiaargyi, mainly eucalyptus brain, ketone, alcohol, and alkane. The aging model was established by intraperitoneal injection of D-galactose for six weeks, and the contents of SOD, GSH, PCO and MDA in the heart, liver and kidney of mice were measured and the morphology of mouse organs was observed. The results showed that the SOD and GSH contents in the heart, liver and kidney of the aging model group were significantly lower than those in the blank control group (p<0.05, p<0.01, p<0.001), and the MDA and PCO contents were significantly increased (p<0.001), the four indicators were much more affected in cardiac organs, SOD and GSH levels were reduced by 57.72% and 44.58%, respectively, and MDA and PCO levels were increased by 43.59% and 86.49%, respectively. The aging mouse model was successfully constructed. Compared with the aging model group, the SOD and GSH contents in the heart, liver and kidney of the wild wormwood volatile oil protection group were significantly increased (p<0.05, p<0.01, p< 0.001), MDA and PCO levels were significantly reduced (p<0.05, p<0.01, p<0.001), of which SOD content had a greater effect on the kidney, increased by 80.42%; GSH and MDA content had a greater impact on the heart, increased by 73.26% and decreased by 46.93%, respectively. The PCO content had a greater impact on the liver, which was reduced by 47.16%. It indicated that the volatile oil of Artemisia argyi has certain anti-oxidation effect in mice. The results of pathological section showed that the volatile oil of Artemisia argyi could protect the morphological integrity of oxidatively injured mouse cardiomyocytes, hepatocytes and kidney cells.

Abstract:In order to provide basis for simple and efficient atmosphere packaging of ‘Lunnan’ apricot, the effects of CO2 concentration on postharvest physiology and quality of ‘Lunnan’ apricot were investigated using different concentrations of CO2 modified atmosphere packaging. The fruits were treated using bags with high (1.50%~2.00% CO2), medium (2.50%~3.00% CO2) and low (3.50%~4.00% CO2) gas transmission rate during storage at (1±1) ℃. The difference of ethylene accumulation in the bag, ethylene release rate and respiration rate by different pathways in the fruit, pericarp Chroma and texture were compared with the control. The results showed that different concentrations of CO2 modified atmosphere packaging during storage period reduced the ethylene release rate and ethylene accumulation in the package to different degrees. The different concentrations of CO2 modified atmosphere packaging reduced the total respiration in glycolysis pathway (EMP), pentose phosphate pathway (PPP), and alternating pathway (AP), and the respiratory peak was delayed by 6~24 days and the peak value was reduced by 12.89%~38.62%. The modified atmosphere packaging could keep the color and texture unchanged, and retard soft decay and weight loss effectively, and the storage quality of the ‘Lunnan’ apricot was well retained. Among the three treatments, medium gas transmission (2.50%~3.00% CO2) was the most effective method in terms of overall quality retention of apricots.

Abstract:Pure milk and lychee juice were used as the main raw materials, with Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus as fermentation strains. The effects of different combinations of three lactic acid bacteria on the fermentation characteristics and texture of set-style yogurt fortified with lychee juice were investigated. The results showed that L. casei showed relatively high ability to produce exopolysaccharide, with the exopolysaccharide content reaching 22.50 g/L when used alone (compared to 5.73 g/L and 0.29 g/L for the fermentation using S. thermophilus or L. bulgaricus alone). After fermentation with different combinations of the three bacteria, the apparent viscosity and water-holding capacity of the yoghurts were positively correlated (R2 = 0.98) with exopolysaccharide content. The L. casei showed a weak acid-producing ability, and the pH after fermentation with the strain alone was higher causing lower hardness, compared with those for the fermentation with its combinations of S. thermophilus or L. bulgaricus. However, the hardness and number of viable lactic acid bacteria were significantly (p < 0.05) higher for the yoghurt fermented by L. casei combined with S. thermophilus or L. bulgaricus, compared with those fermented with Lactobacillus casei alone. Therefore, when the fermentation is performed using the combination of L. casei with S. thermophilus and L. bulgaricus, the advantages of the three strains can be fully utilized, and the total number of colonies, exopolysaccharide content and texture can reach a higher quality level.

Abstract:In this study, the pullulanase gene (pulA) was amplified from Paenibacillus puldeungensis LK18 strain based on the design and primer of its conserved region, and linked to the expression vector pET-28a (+). The recombinant plasmid pET-28a (+)-pulA was transformed into Escherichia coli BL21 (DE3) leading to the successful expression of the recombinant pullulanase. The results showed that the pulA gene had a full length of 1968bp encoded 655 amino acids. The recombinant pullulanase was purified by Ni affinity chromatography and had a specific activity of 508.8 U/mg and molecular weight of 76.95 ku. The optimal temperature of the recombinant enzyme was 45 ℃ and 60% of its enzyme activity was retained after an incubation at 35~40 ℃ for 120 min. This enzyme had an optimal pH of 6.0 and high stability at a pH in the range of 6.0~8.0. The enzyme was activated by K+ and Mg2+ at a concentration of 10 mmol/L, but inhibited by Zn2+, Mn2+, Ni2+, Fe2+, Cu2+, Co2+, and Ca2+ to different extents. In this study, a recombinant strain with efficiently expressed pullulanase was constructed, which had a potential in industrial applications.

Abstract:The interaction between the polyphenols from Pinus koraiensis seed scales and whey protein and associated modes of action were studied by ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy. The analysis by ultraviolet-visible absorption spectroscopy revealed that the polyphenols from Pinus koraiensis seed scales interacted with whey protein and yielded new complexes, which also changed the microenvironment surrounding the spatial structures of the aromatic residues of proteins, and induced the conformational change of whey protein. The fluorescence spectroscopy analysis showed that the polyphenols had a strong fluorescence quenching effect on the whey protein, and the quenching type belonged to the static quenching of the formed complexes. The apparent binding constants (KA) of their interactions at different temperatures were calculated as: 1.111 × 104 L/mol (25 ℃), 2.201 × 104 L/mol (30 ℃), 6.206×104 L/mol (35 ℃), and the corresponding number of the binding sites (n) were 0.885, 0.937 and 1.043, respectively. The analysis of thermodynamic parameters revealed that the interaction between the polyphenols from Pinus koraiensis seed scales and whey protein was an endothermic process, and the main interactive force was hydrophobic interaction.

Abstract:In this study, scallop brim was used as the raw material for enzymolysis by a composite protease. On the basis of the determined optimal temperature for the enzymolysis of scallop brim, the taste characteristics of the scallop brim hydrolysates obtained from enzymolysis for different times were studied, and the changing trends of the taste-active components of different hydrolysates and the taste profiles of the scallop brim hydrolysates with different enzymolysis times were further discussed. The results showed that there were significant differences in the taste of the hydrolysates with different enzymolysis times. Among which, the 8-h scallop brim hydrolysate exhibited the highest umami intensity (9.32), while the 12-h hydrolysate showed the highest bitterness (7.33) and greatest fullness (8.33). These results were mainly due to the strong influence of enzymolysis time on the contents and ratio of umami amino acids and bitter amino acids in the hydrolysates. After the enzymolysis for 8 h, the proportion of umami amino acids was the highest (46.80%) whilst the proportion of bitter amino acids was the lowest (51.67%). In addition, the analysis of molecular weight distribution results revealed that the ratio of the total peptides > 5000 u (which made small contribution to taste) to the peptides < 180 u (which exhibited apparent bitter taste) in the 8-h hydrolysate was relatively low, which may be the main reason for the higher umaminess and fullness and lower bitterness of the 8-h scallop brims hydrolysate. This study provided a theoretical basis and guidance for the industrial use of scallop brim to prepare high-quality taste-active stock materials, through studying the changing trend of the taste-active components of scallop during enzymatic hydrolysis.

Abstract:The influences of different hot-air drying temperatures (40, 60, 80, 100 ℃) on the drying characteristics (drying curve, drying rate curve, fitted drying equation), composition (total polyphenols, total flavonoids, chlorophyll), and properties (antioxidant activity, color changes) of Heracleum moellendorffii Hance were investigated in this study. The results showed that drying time was significantly (p < 0.05) reduced with an increase of temperature. The Page equation was found to describe accurately the hot air drying process and drying characteristics. Hot air drying at 60 ℃ led to significantly (p < 0.05) higher contents of total polyphenols and total flavonoids (10.97 and 3.45 mg/g, respectively) and higher antioxidant activities than at other temperatures. The contents of flavonoids and chlorophyll a in Heracleum moellendorffii Hance were also higher when drying was conducted at 60 ℃. Therefore, hot-air drying at different temperatures exerted significantly (p < 0.05) different effects on the drying characteristics, content of total polyphenols, content of total flavonoids, chlorophyll content, color and antioxidant activity of Heracleum moellendorffii Hance. Taken together, hot-air drying at 60 ℃ could ensure a higher drying rate while maximally preserving the composition and properties of Heracleum moellendorffii Hance.

Abstract:Acidic pollutants in the flue gas have been known as strong toxicity to the environment. Besides, the high concentration of CO2 from flue gas might contributed to the greenhouse effect. Using Chlorella sp as effective biomaterials for fixation of high concentration of CO2 (15%, V/V), this study was to investigate the tolerance to moderate SO2 and NO2 gas derived from self-installation devices with the help of Gibberellin (GA) and triacontanol (TA). The cultures were exposed to SO2-air mixture (1500 mL, 50 mg/kg) and NO2-air mixture (1500 mL, 50 mg/kg) per day respectively, and the results showed that the biomass increased by 1.32 times and 1.27 times for GA addition, and increased by 1.22 times and 1.05 times for TA addition, respectively. Besides, the volumes of the cells became larger when growing with addition of GA and TA. The quantification of biochemical composition including protein, lipid, carbohydrate were investigated and the results showed that GA and TA had the same positive effects on the lipid accumulation and the maximal content of lipid, which amounted to 0.62 mg/mg of dry weight. Nevertheless, the content of protein had no obvious changes with the help of GA and TA. High concentration of CO2 had negative effect on carbohydrate production in the algae and the content of carbohydrate was not elevated by the addition of GA and TA. This study reveals the potential of applying Chlorella sp and growth hormones GA and TA to flue gas capture.

Abstract:The preparation of sulfonated reduced graphene oxide and its adsorption capacity towards basic dyes were investigated in this study. Sulfonated reduced graphene oxide nanosheets (S-rGO) were prepared through grafting aromatic radical-containing sulfonic acid onto chemically reduced graphene oxide (rGO). The synthesized adsorbent sulfonated reduced graphene oxide (S-rGO) was characterized by fourier-transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results showed that the sulfonate was successfully grafted onto graphene oxide (GO). The effects of pH, time and adsorbent dose on adsorption behavior were systematically studied. The results of the adsorption experiments showed that the adsorption process followed the quasi-second-order kinetic model and the Langmuir model, indicating that the adsorption was controlled by the surface reaction process and belonged to monolayer adsorption. In the adsorption and desorption experiments, the adsorption rates of basic orange 21, thioflavine T and rhodamine B were all greater than 99%, with the desorption rates as 98.81%, 86.63% and 94.44%, respectively, indicating that the sorbent S-rGO had good adsorption, desorption and reuse capacities. The use of this material to treat industrial wastewater could prevent the contamination of agricultural products from harmful dyes and their accumulation in the food chain, thereby threatening human health.

Abstract:In this paper, Portulaca oleracea, Pteridium fern, Chuncai and Broccoli were used to evaluate the changes of total polyphenols, total flavonoids and folic acid in microwave treatment, stir-frying, cooking and cooking methods. The transfer rate was used to study the change of total polyphenols, total flavonoids and folic acid. The preservative rate and loss rate are the evaluation indexes. Through the comparative analysis of the three evaluation indexes, the changes of various active components in wild vegetables under different cooking methods can be obtained. The results showed that the preservation rate of total polyphenols was the highest after stir-frying, and the transfer rate of total polyphenols was higher than that of other cooking methods after microwave treatment, and cooking was the best way to make the lowest transfer rate of total polyphenols. After cooking, the actual heat loss rates of Portulaca oleracea, Pteridium fern, Chuncai and cauliflower were higher, and the actual heat loss rate of Pteridium fern could reach 43.37%, all of which were negative under microwave conditions. The preservation rate of total flavonoids in Broccoli was at the highest level, 83.14%. Microwave was one of the most unfavorable cooking methods for the preservation of total flavonoids. In order to ensure the transfer rate of total flavonoids, the cooking method should be adopted; the actual heat loss rate of the vegetable after cooking is higher than that of other cooking methods. In addition, the highest folic acid content was found in vegetables treated by the system. It can be seen that the changes of active ingredients in wild vegetables are different under different cooking methods, and it is necessary to choose the cooking methods reasonably.

Abstract:Effects of different hydrocolloids (carrageenan, konjac gum, guar gum and their combination) on water migration during processing, texture and sensory evaluation of Cantonese Sausage were investigated in this work. Results showed that the water content of Cantonese sausage increased slightly after addition hydrocolloids or their combination (especially for guar gum (19.94%), increased by 4.02%). In the middle of the drying process, hydrocolloids could induce reduction of drying rate. In general, hydrocolloids had no significant effect on the water loss during the process of Cantonese sausage. Addition of hydrocolloids except D3 could improve the sensory quality of Cantonese sausage, especially combination of carrageenan and konjac gum (87.5). Hydrocolloids or their combination (except D3) in an appropriate content could improve the textural properties, especially combination of hydrocolloids. The rehydration rate of Cantonese sausage increased after addition of hydrocolloids, especially guar gum and their combination with the rehydration rate of 3.79%. The combination of hydrocolloids could improve the sensory quality, textural properties and rehydration rate of Cantonese sausage. The influence of hydrocolloids on quality of Cantonese sausage is dependent on their type and combination.

Abstract:Due to the current severe waste and underutilization of walnut meal protein, this study used walnut meal as the raw material to explore and optimize the extraction process of protein from walnut meal using ultrasonic wave. On the basis of traditional alkali extraction, the walnut meal was treated with six-frequency slit type and five-frequency S-type ultrasonic equipment, the protein yield and purity were studied and the comprehensive score (Y) was used to screen the optimal ultrasonic working mode. In the optimal working mode, the ultrasonic parameters were determined by single factor experiments and optimized by orthogonal experiments. The experimental results showed that the optimal ultrasonic working mode was 20/28 kHz using the five-frequency S-type ultrasonic equipment, with the optimum ultrasonic parameters as: power density 120 W/L, ultrasonic time 30 min, ultrasonic temperature 55 ℃, at a material-to-liquid ratio of 1: 25 (m/V), pH 9. Under the optimal conditions, the protein yield reached 71.00%, with the purity as 72.69% and Y value as 71.68%. The five-frequency S-type ultrasonic equipment as a low-power counter-current and divergent device can effectively extract the proteins from walnut meal and enable the production of high-purity walnut protein.

Abstract:To provide new pathways for detoxification of rice bran, the effect of microwave combined with enzymatic hydrolysis on aflatoxin B1 (AFB1) were investigated in rice bran. On the basis of single factor experiment, the factors of material-liquid ratio (X1), microwave time (X2), alkaline protease hydrolysis time (X3) and enzymatic hydrolysis pH (X4) were combined. Design Expert software and Box-Behnken central combination test method were used to optimize the degradation conditions of AFB1 and determine the removal amount of rice bran polypeptide AFB1. The initial concentration of AFB1 in rice bran was 100.14 μg/kg, and the optimum technological conditions were determined by response surface analysis: microwave power 750 W, microwave time 9.56 min; alkaline protease hydrolysis temperature 50 ℃, enzymatic hydrolysis pH 10.74, enzymatic hydrolysis time 1.57 h, enzymatic dosage 0.4%; material-liquid ratio 1:9.96. Under these conditions, the degradation rate of AFB1 in rice bran was 98.68%, and the residual concentration of rice bran polypeptide (1.85 μg/kg) was obtained, which was in agree with the national standard (<10 μg/kg). Compared with single factor treatment, microwave combined with enzymatic method can play a synergistic role and effectively reduce the content of rice bran AFB1. For the process was under mind condition, simple and efficient, it could be used for the aflatoxin contaminated crops.

Abstract:The optimal ionic liquid-based microwave-assisted extraction process of the total flavonoids from Apocynum venetum L. leaves was investigated, and the antioxidant activity of the extract was evaluated. Firstly, the type of ionic liquid was determined in single factor experiments, and the significant factors affecting the extracted amount of total flavonoids in the process were screened out. The extraction conditions were optimized by the central composite post-design with three factors and five levels and the response surface mathematical model. The optimum process conditions were as follows: ionic liquid concentration 0.73 mol/L, liquid-solid ratio 19:1 mL/g, microwave time 10 min, microwave power 483 W, temperature 70 ℃. Under these conditions, the average extraction rate of total flavonoids was 14.10±0.202 mg/g (which was essentially consistent with the predicted value), and the extraction yield was significantly improved compared with that for the conventional extraction process. The three factors affecting the most the extraction yield were ionic liquid concentration, liquid-solid ratio, and microwave power. The results of the antioxidant activity experiments showed that the scavenging rate of ?OH radical and DPPH free radical increased with the increase of the concentration of total flavonoids from Apocynum venetum L. leaves, and exhibited a good dose-effect relationship. The corresponding IC50 values were 27.88 and 13.61 μg/mL (which were 1.71 and 2.26 times of those for Vc, respectively), indicating that the total flavonoids from Apocynum venetum L. leaves had strong antioxidant capacity.

Abstract:In order to determine the optimum ratio of corn flour to rice flour for processing gluten-free pasta, this work compared the effects of different corn flour to rice flour ratios (1:9, 3:7, 5:5, 7:3 and 9:1) on edible qualities of gluten-free pasta, such as cooking loss, TPA texture, tensile property, and optimal cooking time. The results showed that, as the ratio was 3:7, the cooking loss and strength characteristics of gluten-free pasta reached 12.10% and 14.90 g, respectively. The hardness, spring, chewiness and gumminess also reached 105.67 g, 1.19 mm, 0.80 mj and 68.00 g, which was significantly better than the others. Results of scanning electron microscopy also indicated that the internal structure of gluten-free pasta before cooking is more dense and porosity is smaller void when the ratio of corn flour to rice flour was 3:7. Furthermore, a regular three-dimensional network structure was observed in the gluten-free pasta after cooking. However, the gluten-free pasta made of other corn flour to rice flour ratios had a poorer internal structure. Based on the above results, when the corn flour to rice flour ratio was 3:7, the edible quality of gluten-free pasta was better.

Abstract:In order to investigate the best extraction technology of phycocyanin from Spirulina platensis (A. platensisi), the Spirulina platensis dry powder was used as raw material to evaluate the effects of high-speed homogenization on on extraction yield of phycocyanin. The extraction conditions were optimized by means of single factor test and orthogonal designed experiments. Results showed that the extraction yield of phycocyanin was 157.75 mg/g when pH 7.0 PBS buffer as solvent was chose. The optimized condition was as follows: The solid-liquid ratio of 1:20, the extraction temperature of 30 ℃, the extraction time of 40 min and the extraction times of 3. At this condition, the extraction yield of phycocyanin was 213.32 mg/g. By comparing the effects of ethanol, acid and salt precipitation on the recovery of phycocyanin, the results showed that the recovery rate of phycocyanin was 97.10% and the purity of phycocyanin was the highest when 50% ammonium sulfate precipitation method was used. Phycocyanin was extracted by high-speed homogenization and recovered by 30% and 50% two-step salt precipitation. Under these conditions, 239.70 mg/g of phycocyanin with the purity over 0.7 could be obtained from each 1 g Spirulina powder. The UV spectra results showed that the extracted phycocyanin met with the spectral characteristics of the standard phycocyanin product.

Abstract:In this work, a strain of Pediococcus halophilus was isolated from soy sauce moromi and amplified, which was inoculated into the moromi of soy sauce on its early fermentation stage in the amount of 1×106 CFU/g moromi, then the resulting moromi was managed according to the protocol of high-salt and diluted-state soy sauce. The end product was subjected to destructive test under 50 ℃ with shaking of 200 rpm. Then the formation time and content of secondary precipitate were determined using naked eye observation/refrigerated centrifugation, the level of biogenic amine was detected with high efficiency liquid chromatography, the physicochemical indices and flavor were evaluated using titration method and quantitative descriptive analysis (QDA). It was found that Pediococcus halophilus deferred the occurrence of the secondary precipitation for 15 d and reduced 89.12% (p<0.01) of the secondary precipitate and 55.21% of the biogenic amine content (p<0.01), in which tryptamine and tyramine reduced 100% and 77.00%, respectively. The carbohydrate (total sugar and reducing sugar decreased by 56.32% and 64.56%, respectively) in moromi was converted into organic acids (increased by 29.80%) by Pediococcus halophilus, which enhanced the taste of sourness and the notes of sourness and caramel, lowered the taste of sweetness of soy sauce. The changes of taste and aroma of soy sauce caused by inoculating Pediococcus halophilus can be easily adjusted by blending procedure. Therefore, it is a potential method to solve the problems of secondary precipitation and biogenic amine in Chinese-type soy sauce by inoculating Pediococcus halophilus during its early moromi fermentation.

Abstract:In order to control the oxidative browning on the surface of beef during ice-temperature storage and extend effectively the shelf life of beef, this study used the chilled beef as the research object, and treated the beef with tea polyphenols at different concentrations in synergy with ice-temperature (-1 ℃) preservation. The thiobarbituric acid-reactive substance (TBARS) value, drip loss, hardness, color difference and sensory indices of beef after storage for 1, 3, 5 and 7 days were determined. Using beef treated by aseptic distillation and stored at 4 ℃ as Control 1, and beef treated by aseptic distillation and stored at -1 ℃ as Controlled 2, the synergistic effect of tea polyphenols and ice-temperature preservation on the antioxidant activity and color of chilled beef were examined. The results showed that the tea polyphenols at 0.20% worked syngerstically with ice-temperature preservation to provide significantly (p<0.05) greater protection on the antioxidant activity and colour of beef compared to the Controls. On the 7th day of storage, the beef had the highest score, with L* value, a* value, drip loss, hardness and TBARS value were 34.91, 18.25, 0.35%, 4359 g and 0.24 mg/kg, respectively. Therefore, the use of tea polyphenols in combination with ice-temperature preservation could synergistically exert a good antioxidation effect on chilled beef, and facilitated the color stability of beef during storage.

Abstract:On the basis of studying and analyzing the quality of tomato puree prepared by different processes, the present work systematically invesigated the effects of white granulated sugar, brewing vinegar, salt and modified starch on the quality of tomato sauce. The orthogonal test method was used to optimize the product formula of tomato sauce, in order to prepare high quality tomato sauce. The optimal formula and processing technology of tomato sauce obtained by this work were as follows: 25 g super cold broken tomato paste, 25 g hot broken tomato paste, 8 g sugar, 5 g brewing vinegar, 3 g salt, 3 g modified starch, and 33 g water were mixed, and then high quality ketchup was prepared by high temperature sterilization filling. Compared with five tomato ketchup sold from market by sensory evaluation, the highest sensory score (92.2) was obtained from the experimental tomato paste. It indicated that the tomato paste prepared by this experimental formula has certain market competitiveness in senses, and can meet the taste requirements of consumers.

Abstract:Based on the graphite oxide produced by the improved Hummers method, nitrogen-doped graphene nanomaterials were prepared by hydrothermal reduction method using polyaniline as the nitrogen source. The prepared nanomaterials were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Then, the prepared nitrogen-doped graphene was combined with the horseradish peroxidase to prepare an enzymatically modified electrode for the detection of hydroquinone. The catalytic performance of the modified electrode towards hydroquinone was studied by cyclic voltammetry. The results showed that in the presence of H2O2, the enzymatically modified electrode exhibited excellent catalytic activity towards hydroquinone. Under the determined experimental conditions, the linear range of detection, detection limit and sensitivity were 9 × 10-5 ~ 5.075 × 10-3 mol/L, 1 × 10-5 mol/L (S/N = 3) and 84.14 mA/(mol·cm2), respectively, with very good anti-interference ability and selectivity to uric acid, ascorbic acid, Vitamin E, citric acid and glucose. The electrode also exhibited very good reproducibility and had a relative standard deviation (RSD) of 5 measurements as 2.89% . This prepared electrode can also be used for the detection of hydroquinone in water.

Abstract:The aroma compounds and the volatile compoounds of essential oils of the parts of fresh flower, petals, stamens and pistils from Meizhou were analyzed by headspace solid phase microextraction (HS-SPME) and steam distillation combined with gas chromatography-mass spectrometry (GC-MS). The results showed that the main compounds of aroma compounds and volatile compounds of essential oils in different parts of pomelo flowers include terpenoids, alcohols, esters, alkanes, ethers, and aldehydes. The types and relative contents in different parts were significantly different. Farnesol, trans-orange sterol and linalool were detected in all samples as the main compounds which were more than 60%. 27 compounds were identified in essential oil while 25 were identified in aroma. The highest yield of essential oil was stamen which was 0.65%. As a valuable natural resource, pomelo flower was rich in a variety of valuable compounds needed in food, flavor and fragrance, daily chemical industry. Pomelo flower has development and utilization potentiality with wide application prospects.

Abstract:This experiment aimed to determine and evaluate the nutrient content and hematological parameters of the blood in Bactrian camels (camel blood). The total protein content of the blood in Alashan Bactrian camel was determined using BCA protein concentration kit. The contents of amino acids, fatty acids and minerals in the blood were determined by liquid chromatography and mass spectrometry. The blood parameters were measured using an automatic blood cell analyzer. The results showed that the total protein content of camel blood was 78.45%±1.49%. There were 34 amino acids after the hydrolysis of camel blood, with the lysine content being the highest (27.82±1.86 g/L), followed by arginine (23.60±4.17 g/L) and aspartic acid (22.41±1.26 g/L). The essential amino acids in camel blood accounted for 41.01% of the total amino acids, with the ratio of essential amino acids to non-essential amino acids as 0.69, which conforms to the reference protein pattern proposed by FAO/WHO. A total of 19 fatty acids were detected in camel blood, and among which, glutaric acid had the highest content (1900.70±571.02 μg/mL), followed by oleic acid (1342.00±194.12 μg/mL) and eicosapentaenoic acid (11.22±5.24 μg/mL, the lowest). The saturated fatty acids accounted for 60.89% of all the fatty acids in camel blood, and monounsaturated and polyunsaturated fatty acids were responsible for 21.32% and 17.05%, respectively, with long chain, medium chain and odd carbon fatty acids accounting for 47.50%, 52.50%, and 36.13%, respectively. The camel blood was rich in all kinds of minerals needed by the human body, among which the content of sodium was the highest (5300±2300 mg/kg), followed by potassium (1600±100 mg/kg), iron (452.00±35.75 mg/kg), phosphorus (300±20 mg/kg), calcium (90.71±6.03 mg/kg), magnesium (39.40±2.26 mg/kg), zinc (12.43±1.17 mg/kg), copper (0.65±0.06 mg/kg), manganese (54.78±12.32 μg/kg) and chromium (10.21±0.89 μg/kg). The contents of red blood cells, white blood cells and hemoglobin in camel blood were higher than those of cattle and sheep, and the distribution of immune cells was also inconsistent with that for most livestock.

Abstract:A rapid method for the analysis of saponins based on UPLC/Q-TOF-MS/MS was established by using Bupleuri radix with Turtle Blood processed products as raw materials. The analysis was performed on an Acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) by gradient elution. The mobile phase consisted of 0.01% formic acid solution (A)-acetonitrile (B) at a flow rate of 0.3 mL/min, and the injection volume was 2 μL, the column temperature was at 40 ℃.The mass spectrometer was operated in negative mode. Results showed that the compounds with a mass error of less than 5×10-6, a correct isotope distribution and fragment ion were used as the target compounds, using the established screening database. Combined with software Formula Finder, Mass Calculators and other functions, online databases (Human Metabolome Database, PubChem, MassBank, ChemSpider, etc.), and two stage fragmentation rule, a total of 44 saponins were separated and identified in Bupleuri radix with Turtle Blood, including epoxy ether type, isophthalene type,12-ene-type and 12-ene-28-carboxylic acid type saikosaponins. In conclusion, the results demonstrate that UPLC/Q-TOF-MS/MS method is quick, accurate, and efficient for the identification of saponins in Bupleuri radix with Turtle Blood, and provides a feasible method for the selection of quality control indicators and the efficacy of active compounds in Bupleuri radix with Turtle Blood.

Abstract:In order to detect bovine-derived components in meat products quickly and effectively, real-time fluorescence quantitative PCR and digital PCR were used to detect bovine-derived components in meat products. Firstly, the specific primers and probes were designed by multiple sequence alignment according to the specific region of beef single replication genome, then the standard genomic DNA was extracted by phenol-chloroform method. Real-time fluorescence quantitative PCR and digital PCR reaction conditions were established. The purity and concentration of DNA template were determined and the extracted DNA solution was free of impurities. On this basis, the fluorescence quantitative analysis of bovine-derived components was constructed. The specificity, anti-interference and bovine-derived components in meat products were detected by standard curve of PCR. The results showed that both primers and probes have fluorescence signals for beef. The two methods have bovine origin specificity, the detection values are basically consistent with the actual sample values. The two methods have good anti-interference ability. When there are other meat disturbances, the bovine origin can still be accurately monitored. The maximum errors of the two methods were 3.8% and 4%, respectively. The bovine origin components in different meat products can be quantitatively detected. The bovine origin components in 10 beef balls of samples can not be detected by all methods, which verifies the market. Fake meat does exist. It showed that the proposed method can accurately and rapidly detect bovine-derived ingredients in meat products, and is suitable for the detection of meat products in the market. It is of great significance to protect the rights and health of consumers.

Abstract:A method based on isotope dilution (ID), dispersive solid phase extraction (DSPE) couple with UHPLC-MS/MS was presented for determination of 8 phenols, including 4,4’-Isopropylidenediphenol (BPA), 4, 4'-(1-methylpropylidene) bisphenol (BPB), 4,4'- (2,2-Dichlorovinylidene) bisphenol (BPC), 4, 4'-methylene diphenol (BPF), 4, 4'-Sulfonyldiphenol (BPS), 4,4'- (Hexafluoroisopropylidene) diphenol (BPAF), 2,4-Dihydroxybenzophenone (UV-0) and 2,4-Dihydroxybenzophenone (TH1790) in bakery food and raw material (Flour, Flour-improving Agent, Egg Yolk filling et al.). Target compound was extracted by acetonitrile, and purified by C18 dispersion adsorbent (for high oil content such as egg yolk filling, extra fats were removed beforehand by hexane). A total of 8 targets were separated on a C18 column by gradient elution with acetonitrile-ammonium hydroxide as mobile phase, ionized with negative electrospray ionization (ESI -), detected under the schedule of multiple reaction monitoring (schedule-MRM) mode, and quantified with internal standard method. A favorable linearity was acquired in the concentration range of 1.0~200.0 μg/L with the correlation coefficients (R2) better than 0.999, and the limits of detection (LODs) were ranged from 0.5 to 5.0 μg/L. The spiked average recoveries presented 82.10%~113.20%, with the relative standard deviation (RSD, n = 6) of 2.70%~9.50%. These methods are rapid, sensitive and suitable for the determination of 8 Phenols in bakery food and raw material.

Abstract:In order to improve the accuracy of mushroom toxicity discrimination and eliminate individual differences, a method of mushroom toxicity discrimination based on broad learning system was proposed in this work. Firstly, the correlation between each characteristic of mushroom and its toxicity was explored. The results showed that the odor and color of mushroom were the most distinguishing characteristics. These results were consistent with the experience of manual discrimination. Then, broad learning system was established and trained. By comparing performance in diverse sample sizes of different methods, it was found that when the sample size is larger than 1000, the classification accuracy of the broad learning system was higher than 99.5%. Compared with BP-neural network, the proposed method was of high-accuracy and fast-training. Finally, according to the incremental learning algorithm of broad learning system, when the performance of the system does not meet the requirements, the system can be updated quickly by increasing the hidden nodes, and the accuracy can be improved from 98.55% to 99.99% without retraining the whole network. It was possible to discriminate the toxicity of mushrooms in real time. Therefore, compared with other methods, this method of mushroom toxicity discrimination based on broad learning system has the advantages of high accuracy, short training time, rapid discrimination and easy expansion.

Abstract:In this work, primers and probes were designed based on the specific fragment of Ipomoea batatas beta-amylase gene (β-AMY), and a droplet digital PCR method for detection of sweet potato was established. The specificity, sensitivity and adaptability of this method were tested. The results showed that the established method was specific to the detection of sweet potato components. The limit of quantitation (LOQ) and limit of detection (LOD) were 2.53 copies/μL and 0.67 copies/μL, respectively. According to the established linear relationship between copy number concentration (copy number/μL) and the sweet potato quality (mg), the quantitative analysis of 5% and 25% of the sweet potato mass percentage was performed, and the sweet potato content converted according to the linear relationship was 4.15% and 21.33%, respectively. The recovery rates were 83.06% and 85.31%, respectively, and the RSD values were between 6.33% and 6.95%. It showed that this method can accurately quantify sweet potato components with a mass percentage of 5% or more and it indicated that ddPCR method had strong potential in quantifying sweet potato. This method can provide technical support for market supervision of sweet potato and its products.

Abstract:In this study, the quality of Longsnout catfish pieces was quantitatively evaluated based on multiple indicators. The whiteness, tenderness, thawing loss, trimethylamine content, K value (freshness) and TBA (thiobarbituric acid) content were measured for catfish meat samples; the values determined above were normalized by standard deviation. The standardized values were obtained: the whiteness was normalized and the value was recorded as Zx1, the tenderness was normalized and the value was recorded as Zx2, the thawing loss was normalized and the value was recorded as Zx3, the trimethylamine content was normalized and the value was recorded as Zx4, and the K value was standardized and the value was recorded as Zx5, and the normalized thiobarbituric acid content was recorded as Zx6. The mathematical model was established by principal component analysis, and the standardized value was substituted into the evaluationmodel y=-0.095×Zx1+0.168×Zx2+0.34×Zx3+0.342×Zx4+0.313×Zx5+0.328×Zx6, where y is the quality evaluation result of e-commerce catfish meat. The quality of catfish meat was related to thawing temperature and storage time, the lower the thawing temperature, the better the quality of catfish meat, the shorter the storage time, the better the quality of the catfish meat, the obtainedy value determined the quality of the e-commerce catfish meat: y≥1, the quality of the fish is extremely poor, -1

Abstract:The cherries from different regions of Jilin Province contained five heavy metals: lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu) and zinc (Zn). In this experiment, the contents of five metals were determined by atomic absorption spectrometry. First, by using a series of standard solutions and setting up instrument parameters, linear equations and correlation coefficients were obtained, and the precision, recovery and the heavy metal content of test samples were determined. The experimental results show that the content of heavy metals varied among the different regions, with that for the Changbai mountain area lower than those for Changchun, Jilin, Siping, Baicheng and Tongliao areas. Moreover, the heavy metal content in Nanking cherries from the different planting environments also differed, with heavy metal content for the urban cherries slightly higher than that for the wild cherries. The limits of lead, cadmium, zinc, copper and chromium were 0.1, 0.05, 5, 10 and 0.5 mg/kg, respectively. The heavy metal content of the tested cherries was lower than the national standard. The results of this experiment showed that the cherries are safe to eat as a homolog of medicine and food.

Abstract:In this work, a novel monoclonal antibody against histamine derivative was obtained, and an indirect competitive enzyme-linked immunoassay (ic-ELISA) was developed for the analysis of histamine in aquatic products. The histamine hapten was prepared via three steps of chemical reactions, and then, the hapten was conjugated to carrier proteins of BSA and OVA by the active ester method to form immounogen and coating antigen, respectively. The results of UV scanning showed that histamine haptens were successfully conjugated with carrier protein. Histamine antiserum was prepared by immunizing New Zealand white rabbits, and then purified by caprylic acid-ammonium sulfate method. Under the optimized conditions, The IC50 of this developed ic-ELISA was 0.91 ng/mL, and negative cross reactions (CR) of antibody to Histidine, n-acyl histidine, 3-methyl histamine and other histamine analogues and their derivatives were observed, indicating the good specific method. The calibration curve of this ic-ELISA had a linear detection of 0.1~8.1 ng/mL, with the detect limit detection of 0.10 ng/mL. The average recoveries of histamine in fortified aquatic products were in the range of 98.9~130.1%. Therefore, the established ic-ELISA in this work is a practical method for determination of histamine residues in aquatic products.

Abstract:In this work, the food samples of the functional food (Jiangzhong Hou Gu Mi Xi), Leshi potato chips, steamed cake (Gang Rong), small bread (Haushi Lactobacillus yoghurt) were studied, and the corresponding counterfeit samples were selected. The anti-counterfeiting detection of food quality was carried out by fractional calculus method. Ninety true and false samples were obtained in the market. The fractional differential operators and fractional derivatives of the functions were obtained by fractional calculus. The high frequency edge information of the original gray value of the two-dimensional food code was enhanced, while the distribution envelope of the gray histogram was maintained. The basic integrity of the texture details of the two-dimensional food code image was guaranteed so as to realize different analysis. The difference of fractional calculus between true and false two-dimensional codes of food. The results showed that the total initial detection accuracy of the fractional calculus method was as high as 95.56% in the initial classification detection and 88.89% in the cross-validation, which can provide technical support for anti-counterfeiting detection of food quality and provide a theoretical foundation for maintaining the market order of food quality.

Abstract:To detect clenbuterol (CL), a β-Agonist,a visual and rapid method based on aptamer and gold nanoparticles (AuNPs) was established in this study. The aptamer (DNA1) conjugating with clenbuterol, and its complementary DNA (DNA2) were designed and synthetized, respectively. The aptamer-AuNPs probe (probe1) and aptamer complementary DNA-AuNPs probe (probe2) were also synthetized in present study. In the presence of CL, aptamer bound to the target, AuNPs maintained a free state, however, these AuNPs began to aggregate and change color from red to purple in a high concentration of salt. In the absence of CL, aptamer and its complementary DNA formed a stable network, keeping red color. Some parameters, such as the concentration of aptamer, aptamer complementary DNA and salt were optimized, respectively. The results showed that in the optimum conditions, clenbuterol had a good linear relationship ranging from 1 to 1000 ng/mL, with correlation coefficients (R2) 0.991. The visual detection limit was 1 ng/g, and the recoveries at three spike levels ranged from 83.5% to 101.8%.This newly developed method was simple, sensitive, and reliable. It was suitable to detect clenbuterol in actual samples.