微生态制剂在乳制品中的应用研究进展

微生态制剂具有调整人体肠道微生态平衡、提高免疫力、抗肿瘤、抗衰老等多种功能,是生产功能型乳制品的重要元素.微生态制剂在乳制品中的应用对丰富乳制品功能、引导健康饮食、促进乳业发展等都具有十分重要的意义,研究和开发益生菌、益生元和合生元乳制品将成为乳制品发展的主导方向.本文介绍了微生态制剂在乳制品中的应用情况,重点阐述了微生态制剂应用于乳制品中的关键技术.     

固相萃取-高效液相色谱法测定乳制品中三氯蔗糖

建立乳制品中三氯蔗糖的固相萃取高效液相色谱检测方法.采用0.2％乙酸水溶液沉淀蛋白,提取三氯蔗糖,然后通过C18固相萃取柱进行净化浓缩后,采用高效液相色谱-蒸发光散射检测仪进行检测,该方法0.1～0.8g/L范围内以三氯蔗糖进样质量的对数和相应峰面积的对数做标准曲线,R2为0.9991,相关性良好,加标回收率在94％～102％之间,检出限为2.0mg/L(RSN=3).     

气相色谱-质谱法检测乳与乳制品中20种邻苯二甲酸酯

建立了乳与乳制品中20种邻苯二甲酸酯气相色谱-质谱联用仪分析方法.样品用正己烷提取后,采用DB-5MS(30m×0.25mm,0.25μm)石英毛细管柱分离,在进样口温度280℃,传输线温度280℃,离子源温度230℃条件下20种邻苯二甲酸酯完全分离.该方法各组分的相关系数均大于0.9990,线性范围0～10μg/mL,样品加标回收率为80％～109％.邻苯二甲酸二异壬酯、邻苯二甲酸二异癸酯化合物检出限分别为1.0、0.5mg/kg,其他化合物均为0.05mg/kg.该方法具有简单易行,快速准确,灵敏度高等优点.     

世界茶叶拍卖市场发展概况

拍卖市场拥有完整的、详尽的整套制度安排,茶叶拍卖已成为国际茶场上最主要的贸易方式。世界茶叶拍卖市场交易中心主要集中在印度、斯里兰卡和肯尼亚等产茶国,中国作为产茶大国,急需改变国内茶叶销售方式,建立国家茶叶拍卖市场,进而构建社会主义市场经济条件下新型茶叶经济关系的突破口,促进茶叶贸易持续稳定发展。     

Effect of germination on total phenolic compounds,total antioxidant capacity,Maillard reaction products and oxidative stress markers in canihua (Chenopodium pallidicaule)

Germination of cereals/pseudo-cereals has been suggested as an effective method to increase antioxidant compounds. However, this process could also lead to high reducing sugar levels and subsequent Maillard reaction products. The aim of this work was to determine the time course effect of canihua (Chenopodium pallidicaule) germination on: 1) antioxidant capacity, 2) extractable and non-extractable phenolic compounds content, 3) Maillard reaction products and 4) oxidative stress markers. Germination increased antioxidant capacity, phenolic compounds and Maillard reaction products, including advanced glycated end products while it decreased oxidative stress markers. All parameters exhibited a similar time course pattern with a maximum at 72 h. In addition to the increase in phenolic compounds and antioxidant capacity, canihua germination produced advanced glycated end products. The impact on human health of these compounds in germinated seeds deserves future attention.     

鹿产品检测的研究进展

鹿产品是珍贵的中药材,目前市场上存在着严重的以假充真,以次充好的现象,科研工作者对鹿产品的检测做了大量的研究工作。作者回顾了近年来鹿产品检测方面的研究进展,分别从性状检测、显微检测、理化检测及分子检测等几种主要检测方法进行综述,为鹿产品检测的进一步研究提供了参考依据,同时提出了鹿产品检测中存在的问题及进一步研究方向。     

Processing of materials derived from sweet sorghum for biobased products

Sweet sorghum (Sorghum bicolor (L.) Moench) is particularly suitable as a feedstock for a variety of bioprocesses, largely because of its high yields of both lignocellulosic biomass and fermentable saccharides. Sweet sorghum is less economically important for refined sugar production than other sugar crops, e.g., sugar beet and sugarcane, but can produce more raw fermentable sugar under marginal conditions than those crops. In this review, the agronomic requirements of sorghum (viz., water, soil, and nutrient requirements), cultural practices, and plant morphology are discussed from a bioprocessing perspective. Historically, sugar extraction from the plant in the form of juice has been of primary interest; these methods, along with modern developments are presented. Recently, the direct yeast fermentation of sorghum juice for ethanol production has been studied. Additionally, the bagasse resulting from the juice extraction has been used for a variety of potential products: forage, silage, combustion energy, synthesis gas, and paper. The bagasse contains high levels of relatively low crystallinity cellulose, along with relatively labile lignin, and so is itself of interest as a fermentation feedstock. Whole sorghum stalk, and its bagasse, have been subjected to studies of a wide array of pretreatment, enzymatic hydrolysis, and fermentation processes. The potential fermentation products of sweet sorghum are wide ranging; those demonstrated include ethanol, acetone, butanol, various lipids, lactic acid, hydrogen, and methane. Several potential native products of the plant, in addition to cellulose for paper production, are also identified: waxes, proteins, and allelopathic compounds, such as sorgoleone.     

Effect of Microbial Transglutaminase,Dietary Fiber,and Low-Salt Levels Upon Heat-Induced Meagre (Argyrosomus regius) Gels

The effects of microbial transglutaminase (MTGase; 5 g/kg, w/w) and dietary fiber (40 g pea fiber/kg product and 20 g carrageenan + 20 g konjac flour/kg product) on heat-induced meagre (Argyrosomus regius) gels with 25 and 10 g salt/kg, w/w were analyzed.

MTGase addition increased the magnitude of texture variables. Inner pea fiber had an increasing effect on gel texture. The combination of carrageenan and konjac hardened meagre gels (from 22.2 ± 1.4 to 47.3 ± 4.5 N) and enhanced water-holding capacity. Salt reduction with MTGase ensured a gelling quality similar to that of gels from Alaska pollock surimi.     

Antioxidant Potential of Water Hyacinth (Eichornia crassipes): In Vitro Antioxidant Activity and Phenolic Composition

The aims of the present study were (a) to extract and quantify the main phenolic acids and tocopherols from the petiole, leaves, and flowers of Eichornia crassipes; (b) to evaluate the antioxidant capacity of the extracts in four in vitro systems (1,1-diphenyl-2-pycryl-hydrazyl [DPPH] radical scavenging ability, iron chelating activity, reducing power, and prevention of oxidation in a liposome model system); and (c) its effectiveness in retarding lipid peroxidation in fish oil by accelerated stability test. Significant differences were observed in total and individual phenolic contents and in the antioxidant activities of extracts from the various parts of E. crassipes. Out of the 11 phenolic acids analyzed, ethanolic extracts contained high amounts of gallic, protocatechuic, gentisic, and p-hydroxybenzoic acid, whereas, water extracts contained less amounts of a varied number of phenolic acids. Ethanolic extracts of flower, which contained the highest total phenolic content, were found to have high DPPH radical scavenging activity and reducing power. However, ethanolic extracts of leaf exerted a high Fe²⁺ chelating activity and also inhibited lipid peroxidation process both in liposomes and fish oil. Our results demonstrate that E. crassipes, an underutilized aquatic weed, could be a potential natural antioxidant source for food, feed, and pharmaceutical applications.     

Study of Photo and Thermoluminescence Properties to Identify Irradiated Dried-Fishery Products

ABSTRACT

Radiation-specific luminescence properties in irradiated dried-fishery products (pollack, little pollack, clams, and shrimp) were investigated at different dose levels (0–10 kGy). Photostimulated luminescence (PSL) analysis of whole samples was effective for dried clams and shrimp, while low PSL sensitivity was observed in dried pollack and little pollack. Thermoluminescence (TL) analysis was conducted after isolation of silicate minerals, in which the two methods of mineral isolation—density separation and acid hydrolysis—were compared. Irradiated samples were easily distinguishable through the strong TL glow curves, with maximum peaks in temperature range of 150–250°C. TL ratios (TL₁/TL₂) were < 0.1 for nonirradiated samples, while > 0.1 for irradiated. There was a clear effect of applied irradiation dose, with a negligible effect of the method used for mineral separation. The mineral composition showed that feldspar and quartz minerals were mainly responsible for the well-characterized luminescence behavior upon irradiation.