Abstract:Food emulsifier is one of the most consumable food additives, which occupies a very important position in food production and food processing. 49 kinds of food emulsifiers and food additives with emulsifying function approved by National Standard for Food Safety-Standard for the Use of Food Additives (GB 2760—2014) are introduced. The preparation, properties, and application research progress of domestic food emulsifiers are overviewed. Safety evaluation about 114 kinds of food emulsifiers and food additives with emulsifying function by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) is summarized. The research hot issues and development trend of global food emulsifiers are prospected.

Abstract:In this review, standards for veterinary drug residue limits in animal products among Codex Alimentarius Commission, European, USA, Japan, and China are introduced. Comparisons among the above standards are made from veterinary drugs species, target tissue classes, and maximum residue limits(MRL) index values. Furthermore, some measures and advice for improving veterinary drugs maximum residue limits standards in China are raised.

Abstract:Animal products have a very high nutritional value among food components. Bacillus cereus is a common foodborne pathogen in animal foods. This paper reviewed the recent studies on the progress of modeling of Bacillus cereus and its application on the risk assessment. The latest studies about growth models and inactivation models established in foods such as meat, milk and dairy products, eggs and egg products are summarized. Moreover, the interface models and risk modeling application under dynamic environment are also reviewed. As a conclusion, some prospects of Bacillus cereus modeling are analyzed, which might be referred for further studies.

Abstract:In the present study, rice wine was obtained in terms of mixed fermentation of brown rice and glutinous rice by distiller's yeast and yeast. Then, the fermented fruit beverage with pleasant flavor and strong antioxidant activities was obtained by adding mixed fruits (green apple, guava, navel orange, and mango) and acetic acid bacteria. The optimum fermentation conditions were obtained. The ratio of brown rice and glutinous rice was 1∶1 by adding 0.80% distiller's yeast at 30℃ for 3d, and then the mixture was treated with 0.06% yeast at 28℃ for 7d. After that, the mixed fruits were added into rice wine at the ratio of 2∶1, which were fermented by adding 0.30% acetic acid bacteria at 33℃ for 4d. The total sugar, alcohol content, titratable acidity, and pH value of the fermented fruit beverage were 4.62%, 4.41%, 3.00%, and 3.49, respectively. The high total phenol content (1420.14mg/L) of the fermented fruit beverage exhibited strong DPPH radical scavenging capacity (10.14mmol/L) and oxygen free radicals of absorptive capacity (16.65mmol/L).

Abstract:China is one of the largest fruit and vegetable producing countries in the world, but the current situation of fresh sales is severe. Since the increasing of people's living standards and the health awareness, the probiotic lactic acid bacteria fermentation technology has been applied in developing new fermented fruit and vegetable drinks. It has become the main direction of the current fruit and vegetable drinks producing. The experiment researches the ways of screening the probiotic lactic acid bacteria and the processing technology of composite fruit and vegetable juice fermented beverage, main contents and conclusions are as follows. By evaluating the ability of bile and acid resistance of different species of lactic acid bacteria, 5 species which can better adapt to the human gastrointestinal environment have been screened and applied to the rapid fermentation of a mixed drink. The combination of mixed juice was determined through the sensory evaluation. Through orthogonal test, the optimum fermentation conditions were decided. The monoxenie fermentation was conducted under the optimal fermentation conditions. Test results showed that the pH of five kinds lactic acid bacteria fermentation products have reduced significantly while the acidity increased. The acid conversion in fermented juice took place after one week storage. The results of mixed strain fermentation showed that the acidity of the mixed fermentation product was almost as twice as the monoxenie fermentation products, acid conversion occurred after two weeks in a refrigerator.

Abstract:To identify Leuconostoc mesenteroides BD3749 at the subspecies level and to explore the application prospect of this strain in food industry, BD3749 was identified at the subspecies level by molecular biology and biochemistry techniques. The growth of BD3749 in tomato juice supplemented with sucrose was investigated through dynamic monitoring of OD₅₉₅ and pH as well as the remnant amount of sucrose. The productivity of exopolysaccharide (EPS) was determined to evaluate the potential of BD3749 to serve as dietary supplement. The effect of oxygen stress on the amount of EPS was analyzed and the growth condition was optimized accordingly for EPS production. BD3749 was assigned to be L. mesenteroides subsp. mesenteroides based on these studies. Furthermore, BD3749 grew well in tomato juice supplemented with sucrose, and EPS produced was mainly insoluble EPS (iEPS). Subsequently, the effect of oxygen on EPS production was analyzed and the condition was optimized accordingly for EPS production. In the optimized content of oxygen, 14.5g/L iEPS was achieved after 48h fermentation. BD3749 is a strain of L. mesenteroides subsp. mesenteroides, which is generally regarded as safe and can be applied in food industry. With the excellent fermentation performance, BD3749 is a strain of high potential in food industry.

Abstract:Three strains 138#,233# and 366# were isolated from infected strawberry, blueberry and cherry fruit. All the fungal pathogens were identified as Botrytis Nees by morphological characterization and rDNA ITS analysis. The results obtained by the analysis of both morphological characterization and rDNA ITS sequence showed that strains 138# and 366# belonged to the same species and were closely related to B. cinerea (KJ937044.1). In contrast, strain 233# had a close phylogenetic relationship with B. elliptica (EU519207.1). The biolog microbial identification system with FF microplate was applied for 95 different carbon and nitrogen sources utilization tests of three pathogens, and the result of the carbon metabolic fingerprinting showed that three strains had 67 carbon sources in common, including fifty-six optimal carbon sources, one available carbon source and ten unavailable carbon sources. In addition, metabolic profiling revealed that three fungi were all closely related to B. cinerea Pers. BGA and 233# was the nearest to B. cinerea Pers. BGA.

Abstract:The objective of this study was to investigate the endophytic bacterial communities in the seeds of three rice (“Shen 08S”, “He 620S” and “16A007”) in maturity stage. Experimental results showed that the parental seeds of hybrid rice had diversity of the bacterial community structure at maturity stage. The endophytic bacterial communities in “Shen 08S” included 40 OTUs, they were belonged to Firmicutes,Proteobacteria,Actinobacteria and Bacteroidetes, among them, the abundance of the first dominant bacterium Rhizobium was 15.83%, the second and third dominant bacterium was Bacillus, the third dominant bacterium was Sphingomonas and Curtobacterium; The endophytic bacterial communities in “He 620S” included 20 OTUs, they were belonged to Firmicutes,Proteobacteria and Actinobacteria, the abundance of the first dominant bacterium Curtobacterium was 25.33%,the second and third dominant bacterium was Microbacterium and Pantoea, respectively; the endophytic bacterial communities in “16A007” included 24 OTUs, belong to Firmicutes,Proteobacteria and Actinobacteria, the abudance of the first dominant bacterium Pantoea was 35.00%, the second and third dominant bacterium was Micrococcus and Pseudomonas, respectively.From this study, we found that the endophytic bacteria species in the seeds changed with seed maturation, and the seeds in maturity stage were richer in endophytes resources, which can lay the foundation for the development of new microbial inoculants, and the endophytic bacterial community structure has certain relevance in the seeds of hybrid rice which are genetically related.

Abstract:To evaluate the processing quality of saline plum and provide the theoretical basis of lightly saline storage without oxygen, fresh furong plum and furong plum treated by lightly salting without oxygen by various salt concentration treatment (10,2.5,5°Bé) and traditional high salinity treatment (23°Bé) were used as the research. The processing quality indexes during the storage including texture and structure parameters, physicochemical indexes and sensory evaluation were evaluated by the principal components and hierarchical cluster analysis method. PCA (principal component analysis) showed that the 3 PCs represented 83.08% of the total variance could be extracted up by 11 quality indexes, which reflected the directly feeling, viscous feeling, and chewing feeling, respectively. Moreover, 21 samples were divided into three main types in hierarchical cluster analysis, which were group 1(fresh plum), group 17 with high salinity treatments (salinity 23°Bé, salting for 4 months), group 21 (salinity 23°Bé, for 5 months), and the other 18 groups. To compare the plum conserve with raw materials processed by lightly salting treatment (salinity 10°Bé) without oxygen and high salinity treatment, the hardness and chewiness of the former was lower than the latter, while no significant differences were obtained in the other quality and texture parameters. Meanwhile, the processing quality of lightly salting without oxygen was similar to the high salinity treatment.

Abstract:In this study, a method for simultaneous determination of benzoic acid, sorbic acid, saccharin sodium and acesulfame in food by HPLC was established. The samples were extracted by water, precipitated protein by potassium ferrocyanide and zinc acetate, adjusted pH with ammonia water and centrifuged. Agilent ZORBAX SB-Aq column was applied with mobile phase consisting of methanol and 0.02mol/L ammonium acetate solution by gradient elution with a flow rate of 0.7mL/min. Targets were detected by diode array detector detection with detection wavelength of 230nm and a double qualitative determination of retention time and spectra was performed. The spectral scanning range was 200~400nm. Benzoic acid, sorbic acid, saccharin sodium, and acesulfame K could be effectively separated within 14min. A good linear relationship was obtained in the range of 1-100μg/mL. The linear correlation coefficient was greater than 0.9998. The average recoveries ranged from 88.5% to 98.4% and the precision less than 5%. The detection limits ranged from 1mg/kg to 2mg/kg. The method has wide application range, high sensitivity, and good accuracy, and is suitable for the detection of benzoic acid, sorbic acid, saccharin sodium, and acesulfame in various foods.

Abstract:Based on the recent published literatures, this paper briefly states the commonly used pesticides in China’s tea production, compares their domestic and international maximum residue limits, summarizes the relevant main detection techniques, concludes the application and characteristics of sample pretreatment technologies ,such as solid phase microextraction, liquid phase microextraction, dispersive solid phase extraction, and analytical methods in the analysis of pesticide residues in tea samples, including gas chromatography, liquid chromatography, mass spectrometry, immunoassay. The future development trend about the analysis of pesticides in tea is also prospected. This review provides a reference for the further study on analytical methods of pesticides in tea.