蔗糖酯和蔗糖脂肪酸多酯的合成与发展

介绍了食品乳化剂蔗糖酯和蔗糖脂肪酸多酯,重点综述了蔗糖酯和蔗糖脂肪酸多酯的合成方法,包括溶剂法、无溶剂法和相转移催化法等不同的合成方法,并对蔗糖酯和蔗糖脂肪酸多酯的发展作出了建议。     

高效液相色谱法测定蔗糖-6-乙酯

蔗糖-6-乙酯是制备三氯蔗糖的关键中间体,建立一种准确、快速的分析方法测定蔗糖-6-乙酯是这种甜味剂生产质控关键。采用高效液相色谱-蒸发光散射法(high performance liquid chromatography-evaporative light scattering detector,HPLC-ELSD)检测蔗糖-6-乙酯,使用ZORBAX SB-Aq色谱柱,以甲醇水溶液(V(甲醇)∶V(水)=5∶90)为流动相,流速为0. 8 m L/min,蒸发光漂移管温度为85℃,氮气流速为1. 5 L/min。同时对内标法及外标法检测蔗糖-6-乙酯进行了方法学验证。实验表明,2种方法的线性范围均为1. 10～11. 03 g/L,线性相关系数均在0. 99以上,其中外标法的RSD值均小于3. 0%,而内标法的RSD值均小于2. 0%,并且内标法的检出限和定量限均低于外标法,分别为31. 04及103. 46μg/m L。2种方法均能检测蔗糖-6-乙酯,其中内标法略优于外标法。该研究建立的方法可用于蔗糖-6-乙酯的含量检测,并为蔗糖酯的检测分析提供了参考。     

蔗糖脂肪酸酯的制备及应用研究进展

蔗糖脂肪酸酯简称蔗糖酯,是一种良好的表面活性剂,被普遍应用于食品工业。蔗糖酯的合成方法主要包括化学法和酶法,对蔗糖酯的化学合成法进行了详细介绍,概述了酰氯酯化法及酯交换法的操作步骤、优选工艺及优缺点,并与酶法进行了对比。概述了蔗糖酯的结构、理化性质、应用及工业发展现状,以期为蔗糖酯的工业化生产提供参考。     

旋光法测定蔗糖脂肪酸酯中的游离蔗糖

建立了采用旋光法测定蔗糖脂肪酸酯中游离蔗糖的方法。结果表明:蔗糖在0.001～0.05g/mL范围内与旋光度呈良好的线性关系,其线性回归方程为:y=133.38x(g/mL)+0.001,R=0.99999;该方法精密度、稳定性良好。与国标法相比较,旋光法具有简单、快速、易于操作等优点。     

三种TBA方法用于测定腌腊肉制品脂肪氧化程度适用性的研究

本文研究了亚硝酸钠和蔗糖对TBA试验的影响,比较了这两种物质对三种不同的TBA方法(蒸馏法、酸萃取法和样品直接反应法)用于腌腊肉制品脂肪氧化程度测定的适用性。研究发现,亚硝酸钠在酸性或加热条件下与丙二醛反应,导致吸光值降低;此外,TBA在常温下就可以和亚硝酸钠反应生成不可逆产物,利用此反应能够消除亚硝酸钠对吸光值的影响。蔗糖对TBA反应的影响与溶液pH值有关,当反应液的pH值小于2时,蔗糖与TBA反应生成的黄色物质(吸收峰450nm)就会叠加到532nm的吸收峰上,导致吸光值偏高;当反应液的pH值大于2时,蔗糖不会对吸光值产生影响。在三种不同的TBA试验方法中,样品直接反应法受亚硝酸钠和蔗糖的影响不显著(P>0.05)。蒸馏法和酸萃取法试验中TBA值都会随亚硝酸钠含量的增加而降低,随蔗糖含量的增加而升高。     

相转移催化合成大豆油蔗糖多酯初步研究

以大豆油和蔗糖为原料,十六烷基三甲基溴化铵为相转移催化剂,采用两步法合成大豆油蔗糖多酯。初步筛选了合适的助熔剂(脂肪酸皂),并确定了最佳工艺条件:蔗糖粒度120目,搅拌速率500 r/min,催化剂用量3%,反应温度130℃,n(乙酯)∶n(蔗糖)为12∶1,反应时间6 h。在最佳工艺条件下反应得到蔗糖多酯产率达到89.12%,酯化度6.8。对蔗糖多酯和大豆油的理化特性进行了比较,两者性质接近。最后借助薄层色谱(TLC)、红外光谱(IR)对产品结构做了初步鉴定,产品达到预期目标,可以作为普通食用油替代品。     

高效液相色谱法测定车厘子中果糖、葡萄糖及蔗糖含量

采用高效液相色谱法(HPLC)测定车厘子中果糖、葡萄糖及蔗糖的含量。测定方法：Shodex SUGAR系列KS-801(钠型)色谱柱(8 mm×300 mm,6 μm)、流动相为超纯水,流速0.8 mL/min,柱温80 ℃,示差折光检测器(RID)温度30 ℃,进样量20 μL,外标法定量。该法对果糖、葡萄糖和蔗糖测定的平均回收率分别为99.96%、100.30%、99.26%,相对标准偏差(RSD)分别为1.54%、0.49%、0.48%,检出限分别为3.50 μg/mL、4.88 μg/mL、7.50 μg/mL,果糖、葡萄糖和蔗糖的标准曲线相关系数均在0.999以上(n=5)。该法可快速准确的对果糖、葡萄糖和蔗糖定性、定量分析。结果表明,车厘子果肉中果糖、葡萄糖、蔗糖的含量分别为5.69%、5.83%、0.24%。     

响应面法优化蔗糖多酯的合成工艺

以油酸甲酯和蔗糖为原料,十六烷基三甲基溴化铵为相转移催化剂,采用两步无溶剂法合成蔗糖多酯。以蔗糖多酯收率和酯化度为指标,考察反应时间、反应温度、催化剂用量、反应物摩尔比对蔗糖多酯合成效果的影响,用响应面法对蔗糖多酯的合成工艺条件进行优化。实验结果表明,蔗糖多酯最佳合成条件为:反应时间5.1 h,反应温度139.5℃,催化剂用量2.86%,油酸甲酯与蔗糖的摩尔比10∶1。在最佳条件下,蔗糖多酯收率达到86.20%,酯化度为6.69。     

固相萃取-高效液相色谱法测定罐头中三氯蔗糖

目的建立固相萃取-高效液相色谱法测定罐头食品中三氯蔗糖含量的分析斱法。方法样品采用乙酸锌和亚铁氰化钾沉淀蛋白,经过HLB固相萃取小柱净化浓缩,再经C_(18)色谱柱分离,采用蒸发光散射检测器(evaporative light-scattering detector, ELSD)检测。结果该斱法在20.26～405.2μg/mL范围内以三氯蔗糖浓度的对数和相应峰面积的对数做标准曲线,相关性良好(r~2=0.9996)。平均加标回收率为99.6%～105.3%,检出限为0.48 mg/kg。结论该斱法准确、灵敏,能有效、快速的测定罐头食品中的三氯蔗糖。     

近红外旋光法检测食糖的蔗糖分

目的 建立一种近红外旋光法测定食糖的蔗糖分。方法 通过配制纯蔗糖溶液,确定在589.44 nm（589 nm）和880.00 nm（880 nm）波长下蔗糖溶液酸水解前后旋光度差值的比值,基于普通旋光法（国家标准）推导出近红外旋光法计算蔗糖分公式,并将测定结果进行比对。结果 在589 nm和880 nm波长下蔗糖溶液酸水解前后旋光度差值的比值为2.333,在蔗糖分为50%~100%时,近红外旋光法线性关系良好,回收率为98.9%~100.1%,相对标准偏差为0.043%~0.064%,与普通旋光法比对结果一致。结论 该方法灵敏、准确,具有良好的重复性和稳定性,应用范围广,可用于食糖的蔗糖分检测。     

纺纱牵伸胶辊胶圈应用技术概要

阐述棉纺牵伸胶辊、胶圈的应用技术和牵伸原理,重点探讨了胶辊、胶圈的牵伸工艺特性及其合理配置、胶辊制作、周期管理、质量管理、使用管理、产品缺陷与其机械波分析、纺纱环境和挡车工操作水平对纺纱性能的影响,提出胶辊、胶圈有关机件的质量要求等。     

Religious slaughter: Evaluation of current practices in selected countries

As part of the project “Religious slaughter (DIALREL): improving knowledge and expertise through dialogue and debate on issues of welfare, legislation and socio-economic aspects”, this paper discusses an evaluation of current practices during Halal and Shechita slaughter in cattle, sheep, goats and poultry. During religious slaughter, animals are killed with and without stunning by a transverse incision across the neck that is cutting the skin, muscles (brachiocephalic, sternocephalic, sternohyoid, and sternothyroid), trachea, esophagus, carotid arteries, jugular veins and the major, superficial and deep nerves of the cervical plexus. In this report, the restraint methods, stunning, neck cutting, exsanguination, slaughter techniques and postcut handling in the abattoir were assessed for religious slaughter. Information about the procedures used during religious slaughter in Belgium, Germany, Italy, the Netherlands, Spain, the UK, Turkey and Australia was collected by means of spot visits to abattoirs. To standardize the information gathered during the spot visits three guidelines were designed, one for each species, and translated into the national languages of the countries involved. The document included questions on the handling and restraint methods (stunning, neck cutting/exsanguination/slaughter techniques and postcut handling performed under religious practices) and for pain and distress of the animal during the restraint, neck cutting and induction to death in each abattoir. Results showed differences in the time from restraining to stun and to cut in the neck cutting procedures and in the time from cut to death.     

Human risk assessment and TEFs

The concept of toxic equivalency factors (TEFs) has been developed to facilitate risk assessment and regulatory control of exposure to complex PCDD, PCDF and PCB mixtures. Recently the European Centre for Environment and Health of the World Health Organization (WHO-ECEH) and the International Programme on Chemical Safety (IPCS) jointly reevaluated the TEFs of PCDDs, PCDFs and dioxin-like PCBs for mammals and derived consensus TEFs for birds and fish (Stockholm, 1997). From a mechanistic point of view it can be concluded that, although the quantitative response will vary depending on the congener involved, the occurrence of a common mechanism (binding to the Ah receptor) legitimates the use of the TEF concept across species. But there also is criticism regarding the TEF concept. Pharmacokinetic differences between species can significantly influence the TEF value, and uncertainties due to additive or nonadditive interactions, to differences in species responsiveness and to differences in the shape of the dose response curve might hamper the derivation of consensus TEF values. In this context it should be noted, however, that using TCDD alone, as the only measure of exposure to dioxin-like PCDDs, PCDFs and PCBs, would severely underestimate the risk from exposure to these compounds. Therefore, it can be concluded that, for pragmatic reasons, the TEF concept remains the most feasible approach for risk assessment purposes, in spite of the uncertainties associated with its use.     

浅析我国液体牛奶市场消费状况

分析了2001年全国液体牛奶的市场状态和消费结构。在对液体牛奶的市场分析中，叙述了各知名品牌的市场占有率变化；消费者对最佳品牌的认同情况；市场集中度的变化趋势以及WTO对中国液体牛奶市场的影响等。在对液本牛奶的消费分析中，着重阐述了消费者的购买决策影响因素、购物场所的选择、消费频次、饮用类型、饮用时段、饮用场合、饮用目的等方面观点。     

纸质文献保存和修复方法专利技术综述

通过对纸质文献保存和修复领域专利技术文献的收集、分析、标引和梳理,分析了该领域专利技术分布及专利申请情况,分别探析了脱酸、修补、加固、装裱4种技术的专利技术演进路线,最后对该领域专利技术进行了总结。     

乙烯基类聚合物鞣剂共单体种类配比与应用性能相关性的研究

采用单因素二次回归正交试验研究了乙烯基类聚合物鞣剂共单体种类、配比与应用性能的相关性,通过比较不同共单体及其不同配比的乙烯基聚合物鞣剂复鞣革样与对比革样的性能,得到了不同共单体对鞣剂应用性能的贡献。结果表明：含极性基团的共单体有利于复鞣革样抗张强度、耐湿热稳定性的提高,但影响革样的柔软性和革样胶原纤维的柔韧性;共单体丙烯酰胺对复鞣革样的丰满性具有特殊的贡献,鞣剂分子中引入丙烯酸酯类共单体有利于复鞣     

丹蒽醌对氧化脱胶苎麻纤维理化性能的调控

为解决苎麻氧化脱胶中纤维容易被过度氧化而性能受损的问题,在氧化脱胶液中添加了具有纤维素和半纤维素保护效果的试剂 1,8-二羟基蒽醌（丹蒽醌）,并通过调节1,8-二羟基蒽醌的用量实现了对苎麻纤维理化性能（强伸性能、聚合度、半纤维素含量、制成率等）的调控。结果表明,1,8-二羟基蒽醌用量越高,纤维中半纤维素含量、制成率越高;但纤维强伸性能随1,8-二羟基蒽醌含量先升高后降低;当1,8-二羟基蒽醌的用量为2 %时,脱胶的综合效果最佳,此时纤维的断裂功、聚合度、半纤维素含量、制成率比不使用1,8-二羟基蒽醌时分别提高了41.0%、2.0%、17.3%、7.0%;此外,使用1,8-二羟基蒽醌后,脱胶废水的COD值降低了40%,大幅度提高了氧化脱胶工艺的环保性。     

貂绒纤维的基本性能

通过貂绒纤维与山羊绒、骆驼绒纤维的对比,着重就貂绒的形态结构、密度、长度、细度、摩擦性能、卷曲、强力以及纤维的保暖性能等进行了研究。研究表明:貂绒纤维不同于山羊绒纤维,貂绒纤维含有髓质层,进而使得纤维的密度和断裂强度比山羊绒和驼绒小;而对于貂绒的其他基本性能:长度、细度、卷曲度和保暖性等均与山羊绒纤维类似,但与驼绒纤维却有着较大差异。由此可知,貂绒纤维与山羊绒纤维有类似的优良性能,在毛纺上有很高的利用价值。     

Effect of common and new gums on the quality,physical, and textural properties of bakery products: A review

Hydrocolloids (gums) have a good functional characteristic such as emulsifying, gelling, solubility, and textural improvement. In the bakery products, hydrocolloids were used to improving dough performance, bread and cake characteristics, sensorial quality, and extension the products shelf life. Several studies reported the potential use of hydrocolloids in breads, biscuits, cakes, and pasta formulation. The present review summarized the effect of the most common and new hydrocolloids (xanthan, guar, Arabic, carrageenan, karaya, alginate, acacia, methylcellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, locust bean, balangu seed, wild sage seed, basil seed, and cress seed gums) on the rheological, physicochemical, textural, and quality characteristics of bakery products. Gums addition improved volume and porosity of the breads and cakes. Gums influence on the gelatinization and retrogradation of starch and decreased the retrogradation of starch. In the bakery products, hydrocolloids were used to improving mixing and increasing the shelf life of the products through moisture preservation and avoidance of syneresis in some frozen foods. This study summarized the influence of the most common and new hydrocolloids on the rheological, physicochemical, textural, and quality characteristics of bakery products. Addition of seeds gum to the breads, biscuits, cakes, and pasta formula led to an increase in the viscosity of the batter. Also, the firmness of bakery products showed that they became softer with increasing gum levels.     

粗纺羊绒制品外观疵点成因分析

对山羊绒粗纺针织制品常见的外观疵点搓板纱、粗细条纹、松紧捻、薄厚档、云斑纱、毛粒、色差、油污纱、异色毛等进行分类汇总,详细介绍了这些疵点在织物上的表现形式,从纺纱的角度分析了疵点产生的原因,并提出了具体的解决措施,在实际生产中有较强的可行性.此外,着重介绍了搓板纱的表现形式、产生原因和解决措施.对粗纺羊绒针织纱外观质量问题进行了总结,对粗纺企业有一定的参考价值.