Abstract:In 1960s, ethyl hexanoate in Maotai Baijiu (liquor) distilled from fermented grains in cellar bottom was successfully isolated by paper chromatography, which marked the beginning of aroma and flavor study of Baijiu in China. In recent years, with the development of separation and identification technology, researches on aromas from Baijiu had rapidly developed in China. The research status, new trends, new discoveries, and new technology of aromas in Baijiu were summarized, and the research methods were proposed in this study. The general research ideas could consist of four steps, including extraction, separation, identification, and confirmation of active aroma compounds. The application of extraction and Osme techniques in liquor aroma study were presented, while the evaluation of direct injection and liquid-liquid extraction quantitative methods for Baijiu compounds were described. Moreover, the recombinate and omission tests for aroma compounds were also introduced. Finally, the direction of future study on the Baijiu aroma substances was pointed out.

Abstract:In order to evaluate the appropriate values of vitamins in infant and follow-up formula standard of China, this study has taken the vitamins in current national standard as the research objects. The vitamins content data of human milk was inquired and the reference of vitamins for infants and young children, the vitamins intakes, and the health effect of lack/excess were discussed. The commercial products content and other information which had published in recent years has been collected. Moreover, the international organization and other national standards were compared. Based on the analysis, the revision of vitamins appropriate values of China formula standards were recommended. The paper included all the vitamins in infant and follow-up formula standards, proposed suggestions for revision of some vitamins content (including vitamin A, vitamin D, vitamin B₁, vitamin B₂, niacin, folic acid, and pantothenic acid), and put forward the upper limit of the vitamins which have not a maximum in current standards. The results are expected giving proper suggestions to the vitamins content revision in national formula standards of China, so that further ensuring the nutrition and health of infants and young children.

Abstract:The appropriate values of minerals of infant and follow-up formula in China were studied to ensure the safe and nutrition of infants and young children and to refer the infant and follow-up formula standard revision. All 12 minerals in GB standards were studied considering the EU method on nutrients evaluation. The data on seven aspects, such as mineral composition requirements in GB standards, Chinese human milk, mineral recommended dietary intakes, mineral dietary intakes, health consequence, international standards, and the compositional distribution on commercial products, were collected and analyzed, and the adequate value of mineral composition on GB standards were suggested. The results showed that most mineral composition requirements in GB 10765 and GB 10767 could meet the nutritional requirements of infants and young children, while some mineral composition requirements as sodium, iodine, and manganese were suggested to be revised. The extra composition requirements on iron, zinc and phosphorus for soy-based formula were recommended, and the maximum requirements for each mineral composition were proposed to be developed. To sum up, some mineral composition requirements in infant formula and follow-up formula were suggested to be revised.

Abstract:This study investigated the contamination level of Staphylococcus aureus of retail edible mushrooms in China. 699 retail edible mushroom samples were collected from 39 cities in China during 2011 to 2016,3 samples (4.72%) were positive for Staphylococcus aureus and the geometric mean was 9.75 MPN/g. A total of 39 isolates were analyzed.For antibiotics susceptibility tests, all isolated strains were resistant to 22 kinds of different antibiotics, such as ampicillin, and only sensitive to linezolid and rifampicin. Seven isolates were resistant to cefoxitin and carried mecA gene, confirmed as methicililin-resistant Staphylococcus aureus (MRSA).Polymerase chain reaction(PCR) analysis of 18 SE genes showed that 4-6 kinds of enterotoxin genes carried by 60% isolated strains, and sei gene was the most frequently detected, followed by sem,seg,seq,sec,seb,sen.This study reflects the potential risk of Staphylococcus aureus contamination of retail edible mushrooms in China and these isolate strains had virulence potential and drug tolerance, which should be drawn public attention.

Abstract:In order to figure out the growth of Salmonella in fresh pork, the mentioned Salmonella strains were used to make a mixture (10³~10⁴CFU/mL) and artificially contaminate the fresh pork samples. Firstly, the growth dynamics models of Salmonella at different constant temperatures were established. After the internal and external validation, the established growth prediction model was proved highly reliable which can be used to predict the growth of Salmonella in pork. In addition, the change of storage temperature during the fresh pork bought by customers was simulated. According to the equivalent growth time theory, the growth prediction model of Salmonella in pork under the fluctuating temperature was established. After validation of the reliability, the growth of Salmonella under fluctuating temperatures exactly drew from the model. The results demonstrated that the pork should be consumed or preserved at the low temperature as soon as possible to reduce the high risk of food safety owing to the growth of Salmonella.

Abstract:The composition and anti-tumor bioactivity of the exopolysaccharide monosaccharide was carried out by adding Rhizoma gastrodiae alcohol extract to the liquid fermentation system of Grifola frondosa. The HPLC was applied to analyse the monosaccharide composition of exopolysaccharide samples and results showed that the crude exopolysaccharide samples were composed of glucose, mannose, and a small amount of galactose. Whereas the mannose, rhamnose, glucose, galactose, arabinose, fucose etc were the main monosaccharide composition of pure exopolysaccharides. Furthermore, the addition of Rhizoma gastrodiae alcohol extract had a significant change in the content of the monosaccharide component of the exopolysaccharide, but did not produce the new monosaccharide component of the polysaccharide. In the sample of pure exopolysaccharides, the monosaccharide molar ratio of mannose:rhamnose:glucose:galactose, arabinose:fucose was 13.8∶3.9∶5∶3.7∶1∶1.7, while the pure exopolysaccharides fermented with Rhizoma gastrodiae monosaccharide mole ratio was 12.7∶3.2∶5.6∶3.5∶1∶1.6. The results about of the biological activity Grifola frondosa exopolysaccharide on mice macrophage (RAW264.7) showed that the pure exopolysaccharides fermented with Rhizoma gastrodiae had obvious activation on macrophage. The pure exopolysaccharides and exopolysaccharides obtained by fermentation with Rhizoma gastrodiae had certain activation on macrophage. The activation of macrophages by crude exopolysaccha-rides was not significant. In vitro, four polysaccharide samples showed no inhibitory effect on human hepatoma HepG 2 cells.

Abstract:The purpose of this study was to quickly and accurately identify honey and syrup using physical and chemical parameters. Using 17 kinds of honey and 10 kinds of syrup from the northern area as materials, the physical and chemical parameters, such as water content, protein content, molecular weight range, and monosaccharide content ratio, were used to analyze the similarities. In order to improve the resolution of fructose and glucose, an aminopropyl column was applied in this study. The results showed that pH value, polyphenol content, and flavones content were not different. The water contents of 17 kinds of honey were 15.13%-19.88% while the water contents of 10 kinds of syrup were 22.13%-28.50%. The ratios of fructose and glucose of different honey samples and syrup samples were 0.95-1.50 and 0.13-2.80. The protein contents of honey samples were 1.12-5.09μg/g and the molecular weight range was 45.0-116.0kDa. However, the syrup did not have protein. The combination of protein content determination and protein molecular weight assays enhance the persuasiveness of identifying true and false honey through proteins. The moisture content, relative content of fructose/glucose, protein content and molecular weight of protein can be used as indicators of adulteration, and provide the theoretical basis for the identification of honey adulteration.

Abstract:Acanthopanax senticosus is a kind of medicine and food homologous resource peculiar to north China. In order to promote the use of Acanthopanax, Acanthopanax fermentation was made into Acanthopanax senticosus fermentation tea. The solid-state fermentation was applied to deal with Acanthopanax senticosus by using Aspergillus oryzae, Aspergillus oryzae, and Candida utilis for the very first time. The optimum conditions were obtained through the response surface method based on flavonoid contents and sensory scores of tea. Moreover, the antioxidant capacities of Acanthopanax senticosus before and after fermentation were also compared. The results showed that best addition ratio of Aspergillus oryzae, Monascus, and Candida utilis 1∶2∶1, inoculation amount 15%, moisture content 51%, the fermentation temperature 36℃, and the fermentation period 4.5 days. Under these conditions, the sensory quality of obtained Acanthopanax senticosus fermented tea was excellent and the content of flavonoids was 32.37%, which was higher than that of unfermented Acanthopanax senticosus. Meanwhile, the antioxidant activity of Acanthopanax senticosus increased after fermentation.

Abstract:The total flavonoids were extracted from corn silk. The IC₅₀ of ·OH and DPPH radical scavenging of purified total flavonoid were 0.155mg/mL and 0.049mg/mL.The total flavonoids were added to dried pork slices and the antioxidant activity of total flavonoids were evaluated by the POV value, TBA value, and e-nose.BHT and phytic acid were used as the positive control. After 26 days storage, the result showed that POV values of dried pork slices with or without total flavonoids addition were 1.625meq/kg and 3.75meq/kg. The e-nose result showed that the similarity of the odor of the pork preserved with or without total flavonoids was 94.95%. In a conclusion, total flavonoids from corn silk can be used as a natural antioxidant in food.

Abstract:Maillard reaction is a key factor to form the characteristic flavor of chicken crisp floss. To optimize the processing technology of chicken crisp floss to improve product quality, the single factor experiment and orthogonal experiment were used to optimize the processing parameters of cooking time, sugar content, and frying time. The water content, ash content, and color difference of product were detected. The effect of processing technologies on Maillard reaction in the process was also investigated. The results showed that the frying technologies distinctly affected the Maillard reaction. Cooking time of 30min, sugar content of 6%, and frying time of 15min could improve the value at OD₄₂₀, and the ash content and water content of chicken crisp floss were 5.45% and 9.00%. In addition, the analysis of color difference showed that change of black and white color was not distinct. However, red and yellow color was darken. Increased cooking time decreased the protein content and nutritional value of product. Therefore, the processing parameters of chicken crisp floss can affect the Maillard reaction process and impact the product quality.

Abstract:Extraction of peanut oil with SFE-CO₂ was studied by combining methods of uniform design and BP neural network. Taking peanut after being semi-baked and crushed as raw materials, four factors, including extraction pressure, temperature, time, and CO₂ flow rate, were tested at ten levels of each factor. Using the experimental data of uniform design as training samples, a neural network prediction model for SFE-CO₂ extraction of peanut oil was established. The extraction process was predicted, and the relationship between the experimental factors and the oil yield rate was analyzed. Therefore, the better technological condiitions were determined. A 4-9-1 neural network model was established. The prediction value of the oil yield was close to the experimental value, and the relative error (absolute value) was less than 2%. The neural network model could predict the trend of peanut oil yield under the influence of various parameters. Under the conditions of the extraction pressure 30MPa, temperature 40.5℃, time 125min, and the CO₂ flow rate 187L/(h·kg), the expected value of peanut oil yield was 47.5%. The method provides a reliable theoretical basis for the prediction and control of SFE-CO₂ extraction of peanut oil.

Abstract:In order to investigate the influence of Auricularia polytricha powder (APP) addition to Chinese steamed bread (CSB). The CSB with different amounts of APP addition with 0,2.5%, 5.0%, 7.5%, and 10.0% was made. Textural properties were studied using texture profile analysis, and sen-sory evaluation of CSB was performed according to a nine-point hedonic scale. The results showed that with the increase addition of APP, the dough fermentation performance decreased. The texture profiles of dough and CSB have significant changes. The hardness, chewiness, and gumminess of dough and CSB increased and the elasticity, cohesiveness and resilience of dough and CSB decreased. More APP adding led to a significant decrease in the specific volume and the sensory score of CSB (p<0.05). The hardening speed of CSB accelerated significantly (p<0.05), while the pH change was not significant. When addition amount was 5.0%, the assessor’s opinions of CSB were the highest. It could be concluded that the optimum amount of APP addition was not more than 5.0% in making CSB.

Abstract:The traditional food safety monitoring usually adopts the manual monitoring mode,which has the characteristics of low efficiency, poor timeliness, and incomplete data. In order to realize the sharing of resources and information in the process of food safety monitoring, this study designed and developed a food safety monitoring and control system based on the multi-source and big data under the support of Beijing education science and technology innovation platform.The system was designed mainly based on Eclipse's development environment, Java EE development platform, My SQL background database and Java language. The system has many functions including datas' storage, update, fast transmission,share and monitoring in real time. Finally, the pesticide residue experiment was taken as an example, and the analytical spectrum of the system was compared with the spectral waveform collected by Opus. The results were consistent. The experimental results show that the system has the advantages of simplifying manual labor, improving scientific research efficiency, realizing resource sharing, and convenient access.