一种新型二肽甜味剂的合成及表征

以3-环己基-L-丙氨酸、Boc-L-天冬氨酸-4-苄酯为原料合成二肽L-天冬氨酰-3-环己基-L-丙氨酸-1-甲酯(Ⅰ),以3-羟基-4-甲氧基苯甲醛为原料经过Witting反应、H2还原和DIBAL-H还原三步反应合成3-羟基-4-甲氧基苯丙醛(Ⅱ),然后Ⅰ与Ⅱ在氢气、Pd/C催化作用下进行还原氨化反应,得到目标产物N-[3-(3-羟基-4-甲氧基苯基)丙基]-α-L-天冬氨酰-3-环己基-L-丙氨酸-1-甲酯(Ⅲ),总产率为47%。产物的结构采用IR、~1HNMR、~(13)CNMR和HRMS进行表征,并验证其甜度约为蔗糖的25000倍。合成终产物的最佳工艺条件为:n(Ⅱ)∶n(Ⅰ)=1∶1,Pd/C催化剂用量为反应物总重的10%,体积分数80%的甲醇水溶液为溶剂,反应温度35℃,反应时间20 h。     

Oral and intestinal digestion of oligosaccharides as potential sweeteners: A systematic evaluation

The utilisation of oligosaccharides by oral microorganisms and intestinal enzymes are important factors in determining their effectiveness as alternative sweeteners. In this study, classes of naturally occurring sugars were assessed using in vitro models for oral and intestinal digestibility, in order to test the influence of chemical structure on functional properties. Amongst the classes of sucrose isomers, α-glucobioses, β-glucobioses and sucrose-based oligosaccharides, structures were identified that were not utilised by the common oral bacterium Streptococcus mutans, and would therefore contribute to the non-cariogenic potential of a sweetener. Analysis of the rate and products of digestion by a rat glucosidase mixture was used to determine the relative intestinal digestibility. The results showed that oligosaccharides containing a (1 → 6)-β-Glc group, including gentiobiose and gentiobiitol, together with melezitose, a sucrose-derived oligosaccharide containing a α-Glc-(1 → 3)-Fru moiety were resistant to digestion by both S. mutans and mammalian intestinal enzymes, highlighting their potential as dietary sugar substitutes.     

Sugar replacement in sweetened bakery goods

This review presents the state‐of‐the‐art concerning the application of natural and artificial high‐intensity sweeteners, fructans and bulking agents such as polyols as sugar replacers in sweet‐baked goods and their effects on product characteristics. The recent much publicised attention given to weight gain of the population and its consequences on the occurrence of diet‐related diseases in developed countries has influenced the food manufacturers attempts to provide the consumer with reduced energy products. The replacement of sucrose in sweet bakery products by alternative natural or artificial sweeteners can be a challenging issue. Sucrose as a main ingredient in sweet bakery products contributes, aside from providing sweetness, to numerous processing and product characteristics. Intense sweeteners have a high sweetness compared with sucrose but lack in their contribution to the body of the product, whereas the replacement of sucrose with bulking sweeteners may result in products with a similar body but a lack in taste and flavour.     

湿法烟气脱硫技术的应用概述

分析了湿法烟气脱硫的基本原理、脱硫剂的要求、脱硫的类型、工艺和主要的设备。重点分析了石灰石/石灰—石膏法湿法烟气脱硫技术的应用。     

D-阿洛酮糖酶法生产的研究进展

稀有单糖D-阿洛酮糖是D-果糖的C-3差向异构体,主要通过D-塔格糖3-差向异构酶或D-阿洛酮糖-3-差向异构酶对D-果糖进行异构化获得。D-阿洛酮糖不仅可以作为食品添加剂和膳食补充剂,而且具有改善胰岛素抵抗、增强抗氧化和降血糖控制等多种生理功能。因此,D-阿洛酮糖作为传统高能量糖如蔗糖、果糖等的健康替代品,具有重要的研究价值。作者综述了D-阿洛酮糖的理化性质、来源、体内代谢、生理功能、应用和最新生产技术,讨论了D-阿洛酮糖生产中存在的问题及解决方案。针对低废物生成、低能耗、高糖产量等特点,提出了一种绿色、可循环利用的D-阿洛酮糖生产工艺技术。     

三氯蔗糖的安全性研究进展

三氯蔗糖是一种非营养合成甜味剂,目前已广泛应用于饮料、食品、医药等行业,为评价其使用的安全性,国内外相关学者对其急性和慢性毒性、致癌性、生殖毒性等方面进行了大量研究,就三氯蔗糖在体内的吸收代谢、毒性以及国内外批准使用情况等方面进行了综述。     

三氯蔗糖的制备及新的甜受体模型

１′,６′－二氯－１′,６′－二脱氧－β－Ｄ－呋喃果糖基－４－氯－４－脱氧－α－Ｄ－吡喃半乳糖苷（俗称三氯蔗糖,其商品名为Ｓｕｃｒａｌｏｓｅ）是一种新型甜味剂。该甜味剂品味好,甜度高,其甜味完全接近蔗糖,而且加工性能优良,它对温度和ｐＨ稳定,也不会给食品口味、色泽、组织带来不利影响,是糖精、乙酰磺胺钾及二肽酯类的阿斯巴丹和阿里甜等甜味剂不可替代的优良甜味剂,具有广泛的市场开发前景。本文还提出了一种新型甜受体模型以识别和探求新的甜味分子。     

几种糖醇类甜味剂在调配型酸乳饮料中的应用研究

对几种糖醇类甜味剂在调配型酸乳饮料中的应用与蔗糖进行了对比研究，发现结晶麦芽糖醇、液体麦芽糖醇均可作为良好的蔗糖替代品生产无糖调配型酸乳饮料。     

甜味剂甘草酸的不同提取方法研究

根据甘草酸的物理化学性质制定了四种不同的提取方法,对其进行高效液相色谱分析。由进样峰面积测出甘草酸的含量,确定最佳提取方法。结果表明,氨:乙醇:水提酸沉法提取的甘草酸含量为最高,为工厂的大规模生产甘草酸提供理论依据。