功能性棉型织物服用性能的模糊综合评判

研究功能性棉型织物综合服用性能优劣的模糊评价方法。对几种不同规格的功能性棉型织物的透气量、悬垂系数、折皱回复角、回潮率、透湿量、芯吸高度等性能进行了相关测试,采用模糊数学综合评判方法对测试数据进行处理分析,通过对权系数和标准化值的计算求算出综合评判值,得到了功能性棉型织物综合服用性能优劣的排序。指出:利用此分析过程对织物整体性能进行评估,既兼顾到织物的综合服用性能,又考虑到各性能权重分配上的差异,分析方法简单、合理、可靠,且评判结果较好。     

Discussion on the determination of sail residue in silk fibroin solution with a water quality testing pen北大核心CSCD

the salt residue is one of the quality indexes of silk fibroin products.The products with low salt residue are not only healthier for human body, hut also more stable in exterior qualities, such as color and smell.Instrumental analysis and chemical analysis are currently methods to accurately determine salt residues in silk fibroin products, but they still need to be supplemented by real-time and quick detection methods in practical production.This paper discusses the determination method with a water quality testing pen and investigates the response of the water quality pen to the changes in the concentration of a variety of solutions, and associates with application examples.The results show that the TDS measured by the water quality pen is highly linearly correlated with the changes in the concentrations of CaCU , NaCl, and fibroin-CaCU solutions.The principle and method of the TDS water quality testing pen have an application prospect in the field of real-time and rapid approximate evaluation of salt residue in silk fibroin solution. © 2021 China Silk Association. All rights reserved.     

澳洲金鲈鱼种肌肉中氨基酸与脂肪酸组成的分析

目的研究澳洲金鲈肌肉中营养成分组成。方法采用色谱法和常规分析化学法检测出澳洲金鲈鱼种肌肉中蛋白质、脂肪、氨基酸和脂肪酸等含量,并对肌肉中氨基酸与脂肪酸组成进行分析和评价。结果澳洲金鲈鱼种肌肉中含有17种氨基酸(未测色氨酸),在必需氨基酸中含量最高的是赖氨酸,含量最低的是蛋氨酸,必需氨基酸占氨基酸总量的39.67%;第一限制性氨基酸是蛋氨酸和胱氨酸;氨基酸比值系数分为78.55%;必需氨基酸指数为89.64%;澳洲金鲈的蛋白质营养符合E/T应为40%左右和E/NT应为60%以上的参考蛋白质模式标准。澳洲金鲈含有22种脂肪酸,含量最高的是油酸,亚油酸次之;不饱和脂肪总量为64.4%。结论澳洲金鲈具有营养价值高、味道鲜美等特点,可以作为我国优良品种引进及产业化开发的淡水鱼。     

仿瓷餐具中两种聚合起始物迁移量的关联研究

目的 了解我国仿瓷餐具中三聚氰胺和甲醛迁移情况以及两者迁移是否存在关联,为以后进行危险性评估奠定基础.方法 采用分光光度法测定模拟物中甲醛的迁移量,高效液相色谱法测定模拟物中三聚氰胺的迁移量,迁移实验条件为90℃,30 min,模拟溶剂为3％乙酸.结果 41个样品中,有28个样品检出三聚氰胺,其中最大值为0.85 mg/dm2,最大迁移量约为欧盟限量标准的17.0％,所有样品的三聚氰胺迁移量均未超过欧盟的限量值;41个样品中,全部检出甲醛,其中最大迁移量为270.56 mg/dm2,约为欧盟限量标准的108.2倍,有22个样品超过欧盟的特定迁移量规定,超标率达53.66％;41个样品中有27个样品甲醛与三聚氰胺的迁移量的比值大于6,最大比值为10 033.0,是文献中所提供最大比值6的2 090.2倍.结论 仿瓷餐具中甲醛的迁移值异常高而三聚氰胺的迁移量为未检出时,其不为三聚氰胺-甲醛(密胺)餐具的可能性极大.目前市售的仿瓷餐具的安全性值得进一步的关注.     

Twenty-five years of total antioxidant capacity measurement of foods and biological fluids: merits and limitations

This review summarises 25 years of investigations on antioxidants research in foods and biological fluids and critically analyses the merits and limitations of using the total antioxidant capacity (TAC) measurement in the metabolomic era. An enormous bulk of knowledge was produced regarding the antioxidant capacity of foods and large TAC databases were developed. A direct link between a food TAC value and any health benefit is erroneous and has led to several cases of consumer deception. However, the striking epidemiological evidence associating a high dietary TAC with some disease prevention and the availability of well-constructed TAC databases deserve attention and must be taken into account to establish the usefulness of measuring TAC in both foods and biological samples. The in vivo TAC measurement, usually performed in plasma, is influenced by many external factors, such as dietary habits, as well as environmental and behavioural factors, which are integrated towards homeostatic control by fine physiological mechanisms with high inter-individual variability. Therefore, plasma TAC cannot be considered as a unique biomarker of individual antioxidant status. However, the combined evaluation of plasma TAC with known markers of disease, individual metabolism, inflammation and genetics, as well as with markers of gut microbiota composition and activity, may lead to the identification of populations that are more responsive to food/diet TAC. In this framework, the appropriate use of TAC measurement both in food and in vivo can still provide support for the interpretation of complex phenomena and be a tool for sample screening when making a quick decision toward in-depth research investigations. © 2018 Society of Chemical Industry     

Additional modules for versatile and economical PCR-based gene deletion and modification in Saccharomyces cerevisiae

An important recent advance in the functional analysis of Saccharomyces cerevisiae genes is the development of the one-step PCR-mediated technique for deletion and modification of chromosomal genes. This method allows very rapid gene manipulations without requiring plasmid clones of the gene of interest. We describe here a new set of plasmids that serve as templates for the PCR synthesis of fragments that allow a variety of gene modifications. Using as selectable marker the S. cerevisiae TRP1 gene or modules containing the heterologous Schizosaccharomyces pombe his5⁺ or Escherichia coli kan^r gene, these plasmids allow gene deletion, gene overexpression (using the regulatable GAL1 promoter), C- or N-terminal protein tagging [with GFP(S65T), GST, or the 3HA or 13Myc epitope], and partial N- or C-terminal deletions (with or without concomitant protein tagging). Because of the modular nature of the plasmids, they allow efficient and economical use of a small number of PCR primers for a wide variety of gene manipulations. Thus, these plasmids should further facilitate the rapid analysis of gene function in S. cerevisiae. © 1998 John Wiley & Sons, Ltd.     

食品中还原糖含量测量的不确定度评估

根据JJF1059-999《测定不确定度的评定与表示》和GB／T5009．7——2003食品中还原糖含量的测定原理，建立不确定度的数学模型。系统分析并计算食品中还原糖测量全过程的不确定度各分量、结果标准不确定度及扩展不确定度．此方法适用于评估食品中还原糖含量的不确定度。     

我国与CAC、美国、欧盟食用香料安全性 评价的比较研究

目的:探寻我国在食用香料安全性评价中存在的不足,提出改进与完善该评价体系的建议.方法:搜集我国、CAC、美国和欧盟现行有效的食用香料安全性评价体系与暴露评估方法的相关资料,对其进行比较研究.结果:CAC、美国、欧盟和我国在有关食用香料安全性评价机构、暴露评估方法和安全性评价程序等方面不尽相同.结论:我国在暴露评估方法及暴露量数据、安全性评价程序、毒性资料数据库建立等方面存在一些不足,建议进一步完善我国对食用香料的安全性评估,并进行使用效果评价,建立较为完善、便于查询的毒性资料数据库等.     

应用模糊数学方法评价水牛乳Mozzarella干酪发酵剂

以发酵剂的产酸性能、黏度大小、双乙酰含量、pH4.6可溶性氮含量、滋味等五项为评价指标,应用模糊数学综合评价方法评价水牛乳Mozzarella干酪发酵剂中球菌与杆菌比例。结果表明,Lb.与St.以1∶1.2的比率混合时,模糊概率达0.83,菌种的综合品质最好,且与其它比率的菌种在统计学上存在显著差异(p<0.05)。