微胶囊技术及其在军用食品中的应用

介绍了微胶囊技术的技术特点及最新研究进展,结合军用食品的技战术特点,分析了微胶囊技术在现代军用食品领域的应用前景.     

烘烤大豆休闲食品的研制

以大豆为原料,经浸渍、分选、晾晒、烘烤等工艺生产了一种具有独特风味和高营养的休闲食品,为大豆资源的开发利用开辟了一条新途径。     

酶联免疫吸附技术在食品安全检测中的应用

酶联免疫吸附是将抗原抗体反应的高度特异性和酶的高效催化作用相结合发展建立的一种免疫分析技术.文中主要从农药残留、兽药残留、违禁药物、转基因食品、病原微生物、生物毒素以及其他成分等几方面,对该技术在食品安全检测中的应用进行了综述,并提出了存在的问题以及相应的解决办法.     

酸性食品中还原糖含量的测定

在 DNS 法测定还原糖含量的过程中,酸性食品中的非还原性二糖在加热预处理和煮沸滴定时可以水解为还原性单糖,从而影响还原糖含量的准确测定。本文建立了一个基于酸碱中和反应有效阻断二糖水解效应的改进方法,结果证实中和处理能显著提高酸性食品中还原糖测定的准确性。     

仿生技术与食品科学

食品仿生学是食品工程学与仿生学相结合的新生学科。该文对仿生技术在食品科学中的应用进行了综述,食品仿生学研究的主要内容:食品的模拟合成、食用资源的开发与利用、食品生产过程调挖优化、食品品质感官评价、生物材料、新装备的仿生设计等方面。     

抗衰老功能性食品研究进展

衰老已成为当今人们关注热点问题之一,该文介绍衰老理论学说、作用机理和本质及因衰老引发各种典型疾病,并对抗衰老功能性食品开发及其前景进行展望。     

乳清蛋白在运动营养中作用

该文通过对乳清蛋白成分介绍,阐明乳清蛋白对于运动营养益处,主要表现为提高免疫力、抗氧化、防止损伤与疲劳等方面,并指出运动饮料将成为乳清综合利用一个重要方向。     

Hot topic: application of support vector machine method in prediction of alfalfa protein fractions by near infrared reflectance spectroscopy

The object of this study was to explore the potential for support vector machine (SVM) to improve the precision of predicting protein fractions by near infrared reflectance spectroscopy (NIRS). Generally, most protein fractions determined in Cornell Net Carbohydrate and Protein System (CNCPS), especially the neutral detergent insoluble protein (NDFCP) and acid detergent insoluble protein (ADFCP), could not be accurately predicted by the commonly used partial least squares (PLS) method. A recently developed chemometric method, SVM, was applied in NIRS prediction of alfalfa protein fractions in this study. Two hundred thirty alfalfa samples were scanned on a near infrared reflectance spectrophotometer, and analyzed for crude protein (CP), true protein precipitated in tungstic acid (TCP), borate-phosphate buffer-insoluble protein (BICP), NDFCP, and ADFCP. These 5 laboratory proteins and the CNCPS protein fractions A, B1, B2, B3, and C were predicted by NIRS using the PLS and SVM methods. According to PLS-NIRS regression, CP, TCP, BICP, A, and B2 obtained the determination coefficient of prediction of 0.96, 0.91, 0.94, 0.94, and 0.93, and the ratios of standard deviation of prediction samples: standard error of prediction samples (RPD) values were 5.07, 3.31, 3.98, 3.96, and 3.91. Neutral detergent insoluble protein, ADFCP (fraction C), B1, and B3 were predicted with of 0.75, 0.83, 0.30, and 0.62, and RPD values of 1.98, 2.42, 1.20, and 1.62; Calibrated by the SVM-NIRS method, values of CP, TCP, BICP, NDFCP, ADFCP(C), A, and B2 achieved 0.99, 0.97, 0.97, 0.90, 0.93, 0.97, and 0.97, respectively. The RPD values of those fractions were 8.68, 8.26, 6.11, 3.08, 3.69, 5.97, and 5.81, respectively. The and RPD values of fractions B1 and B3 were 2.67 and 0.87 (B1) and 2.51 and 0.75 (B3) directly predicted by SVM-NIRS model. In this study, the chemical analysis results of B1 and B3 were also correlated with calculated results from TCP-BICP and NDFCP-ADFCP, which were predicted by SVM-NIRS models. The B1 protein fraction achieved and RPD values of 0.87 and 3.61, whereas values for B2 were 0.75 and 2.00. Data suggested that use of SVM methods in NIRS technology could improve the accuracy of predicting protein fractions. This study showed the potential of increasing the NIRS prediction accuracy to a level of practical use for all protein fractions, except B3.     

Microbial Assessment in School Foodservices and Recommendations for Food Safety Improvement

ABSTRACT:  This study evaluated microbial food safety in school foodservices. Five school foodservices were randomly selected, and samples from water, cooking utensils, tableware, foodservice surroundings, and linen were collected in summer and winter ( N = 420). Tap and drinking water samples were collected, samples of food contact surfaces were collected by swab-kit, and samples for foodservice workers' hands and gloves were prepared by glove juice method. Aerobic plate count (APC) and coliform bacterial populations were enumerated on plate count agar (PCA) and desoxycholate lactose agar, respectively. The presence of Escherichia coli , Salmonella , Listeria monocytogenes , and Staphylococcus aureus was also examined by biochemical identification tests. In addition, PCA agar for APCs and Baird-Parker agar for S . aureus were used to enumerate airborne microorganisms. Higher APCs (< 0 to 5.1 log CFU/mL) than acceptable level were generally observed in water samples, while low coliform counts were found in the samples. High APCs were enumerated in cooking utensils, foodservice workers, tableware, and foodservice surroundings, and coliforms were also found in the samples for both seasons. The presence of Salmonella was found from only 10% of plastic glove samples (summer), and the presence of L . monocytogenes was not observed in all samples. S . aureus was detected in some of water, cooking utensils, tableware, employees, and foodservice surroundings, and E . coli was observed in cooking utensils (10% to 20%; summer). No obvious airborne bacteria were detected. These results showed that sanitation practice in school foodservices should be improved, and the results may be useful in microbial assessment of school foodservices.     

Antioxidant effects of flavonoids used as food additives (purple corn color, enzymatically modified isoquercitrin, and isoquercitrin) on liver carcinogenesis in a rat medium-term bioassay

To clarify the effects of purple corn color, enzymatically modified isoquercitrin (EMIQ), and isoquercitrin (IQ), registered as natural food additives in Japan, on liver carcinogenesis in vivo, a medium-term bioassay was employed. A total of 100 male F344 rats were divided into 5 groups; groups 1 to 4 were given a single intraperitoneal injection of diethylnitrosamine (200 mg/kg b.w.) on day 1. From weeks 2 to 8, they were administered basal diet purple corn color, EMIQ, or IQ as containing test chemicals at doses of 1.0% (groups 1 and 5), 0.1% (group 2), 0.01% (group 3), or 0% (group 4) (experiments 1, 4, and 5). All rats were subjected to two-thirds partial hepatectomy at week 3 and were sacrificed at week 8. Purple corn color exerted no significant modifying effects on GST-P positive foci, preneoplastic foci, development in the liver. However, serum of rats treated with purple corn color provided evidence of antioxidant power significantly by potential antioxidant (PAO) test in vivo (experiment 2). And microarray analyses showed purple corn color to induce RNA expression such as P450 (cytochrome) oxidoreductase, phosphatidylinositol 3-kinase, and phospholipase A2 (experiment 3). Higher doses of EMIQ or IQ with strong antioxidant power in vivo by PAO test treated groups were correlated with smaller numbers of GST-P positive foci, with Spearman's rank correlation coefficients of P= 0.002 and P= 0.049, respectively (experiments 4 and 5). Therefore, the tested food additives may be effective as antioxidants in vivo and have chemopreventive potential against liver preneoplastic lesion development.