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。     

新型天然低热甜味剂——非洲竹芋甜素

简述了 非洲竹 芋甜素的 结构、理 化性质、制取方法和安全 性, 并对它 在食品 中的应用 和发展进行了探讨。     

UV-induced Persulfate Oxidation of Organic Micropollutants in Water Matrices

ABSTRACT

The efficacies of UV photolysis, UV-activated persulfate (UV/PS), and combined UV/Fe²⁺-activated persulfate (UV/PS/Fe²⁺) systems for degrading of different organic micropollutants in ultrapure water and groundwater were examined and compared. The studied micropollutants belonging to the different classes involved an artificial sweetener acesulfame K (ACE), beta-lactam antibiotic amoxicillin (AMX), and endocrine disrupting compound 4-nonylphenol (NP). Among the studied systems, the UV/PS/Fe²⁺ process showed the highest performance both in degradation and in mineralization of ACE (UVA-induced systems; k_app = 0.126 1/min and 80.3% TOC removal) and AMX (UVC-induced systems; k_app = 1.383 1/min and 85.4% TOC removal), followed by the UV/PS process. In the case of NP trials, the application of UVC/PS systems was the most promising, and after careful adjustment of oxidant concentration, it demonstrated a considerable improvement in the target compound degradation (at a NP/PS molar ratio of 1/4 k_app = 0.024 1/min) compared with the UVC photolysis (k_app = 0.016 1/min). Irrespective of the applied UV-induced treatment process, the efficacy of target compounds degradation was lower in groundwater as compared with ultrapure water trials.     

紫苏葶和乳酸薄荷酯滴丸在卷烟中的应用研究

为改善卷烟抽吸时容易产生的干燥感,增加卷烟的生津感和甜润感,提高卷烟抽吸舒适性,采用化学合成方法并选用合适的复配比例,制备得到具有较好清甜味的新型甜味剂———紫苏葶和乳酸薄荷酯复配物。将该甜味滴丸添加到卷烟滤棒中,通过烟气气流的带动缓慢释放出其中的甜味物质。对添加有该种滴丸的卷烟各项理化指标及烟气中甜味剂转移率进行测试评价。结果显示:在卷烟滤棒中添加0.15 mg/支的该新型甜味剂,烟气较协调,而且烟气变细腻柔和、有较强的清甜味,刺激性降低。烟支外观和常规理化指标均能满足产品要求,烟气中甜味剂有效成分转移率达到2.5‰以上。     

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。     

Redesigning a sweet protein: increased stability and renaturability

Monellin is one of two natural proteins from African berrieswith potent sweet taste. Monellin is the smaller of the two,and consists of two peptides. The protein loses sweetness whenheated above 50°C under acidic pH. Based on the crystalstructure of monellin we have fused the two chains into a singlechain using several different linkers copied and ‘transplanted’from the same molecule. One of the newly designed proteins isas potently sweet as the natural one, is more stable upon temperatureor pH changes, and renatures easily even after heating to 100°Cat low pH.     

纽甜的应用及研究进展

介绍了新一代强力甜味剂——纽甜的特性、应用及其研究进展,重点讲述了其前体3,3-二甲基丁醛目前所采用的一些合成方法。      

无糖软儿梨含片生产工艺研究

对具有营养保健功能的无糖软儿梨含片的加工工艺进行了初步研究,结果表明,采用软儿梨浓缩膏6%、甜味剂75%(山梨糖醇:木糖醇:结晶麦芽糖醇为3∶0.5∶0.5)、低聚异麦芽糖18.5%、柠檬酸0.5%等基本原料配比,以50%乙醇溶液作润湿剂,0.5%硬脂酸镁作润滑剂,经混合、造粒、干燥、压片等工艺,制成了低糖、低热量、具有保健功能的无糖软儿梨含片.     

高甜度蔗糖衍生物的研究(Ⅰ)——三氯蔗糖及其制备原理

三氯蔗糖是一种全新概念的食品甜味剂,具有甜度高、甜味特性好、安全性高等突出优点,代表着当前强力甜味剂的最高成就.目前全世界仅英国Tate&Lyle公司有生产,但其生产技术尤其是核心步骤与工艺参数秘而不宣.本文首先讨论蔗糖卤代衍生物的增甜原理,及通过全基团保护法制备三氯蔗糖的原则.     

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.