阿斯巴甜的生产与应用

随着工业生产技术的发展及人民生活水平的提高,一方面食糖的生产量已满足不了不断增长的市场需要;另一方面人们认识到食糖摄入过多对人体健康有着不良的影响。因此,20世纪万年代以后,用生物技术或化学合成法开发出一系列甜味物质,成为食品添加剂的一个主要门类。甜味利按其性质可分为两大类：1类是提供热量,参加新陈代谢的营养性甜味剂,如大豆低聚糖、木糖醇、麦芽糖醇、和氢化淀粉水解物等等。另1类是具有甜味,但不参加新陈代谢,不提供热量的非营养性甜味剂。上述几种营养性甜味剂的甜度都不及蔗糖,因此尽管味质较好,但使用时会增加产品的成本,国内推广存在一定的困难,仅在糖尿病患者专用食品及防龋食品中得到应用。对于非营养性     

甜味剂的甜度及影响因素

甜味剂的甜度及影响因素于世水天津开发区康惠食品添加剂有限公司３００４５２ｌ前言甜味剂是指能赋予食品甜味的一种调味剂,按营养成份可分为营养型和非营养型;按来源渠道可分为天然型和人工合成型。但不管如何分类,其甜度是人们最关心的指标,也最容易引起歧义。弄清...     

非营养性高倍甜味剂的现状及发展

甜味剂是很重要的一类食品添加剂,尤其是非营养性高倍甜味剂的品种越来越多,应用越来越广.介绍了目前常用的几种人工合成的以及天然的非营养性高倍甜味剂的特性,并分析了高倍甜味剂的发展趋势.     

新型甜味剂及其在食品工业中的应用

传统食品工业主要使用单糖和非功能性双糖作为甜味剂,如蔗糖、葡萄糖、乳糖、麦芽糖和果糖等。这些糖类物质含有较多的热量,如摄入量过多,易引进肥胖症、糖尿病、心血管病、高血压、龋齿等疾病,不利于身体健康。因此,开发、利用新型甜味剂有着广阔的前景。近年来,食品工作已开发研制出许多新型甜味剂,按性质和作用可分为两大类,一是功能性新型甜味剂;二是高甜度的新型甜味剂。这两类新型甜味剂,都是低热值、不会引起龋齿和血糖升高,弥补了传统甜味剂的不足,有些产品已在食品工业中得到了广泛的应用。     

人工合成甜味剂的特点及其发展趋势

甜味剂是一类能赋予食品甜味的食品添加剂,按其来源可分为天然甜味剂和人工合成甜味剂,其中人工合成甜味剂又分为磺胺类、二肽类、蔗糖衍生物三类。人工合成甜味剂由于在人体内不进行代谢吸收、不提供热量或因为其用量极低而热量供应少且甜度是蔗糖的几十倍至几千倍,又被称为非营养型甜味剂或高倍(高甜度)甜味剂。目前,我国经全国食品添加剂标准化技术委员会审定,由卫生部批准实施的食品添加剂使用卫生标准GB2760中允许使用的人工合成甜味剂共计7种,其中在市场上比较常见的有糖精钠、甜蜜素、安赛蜜、阿斯巴甜、三氯蔗糖等。     

甜味剂的发展现状和影响

甜味剂是目前广泛应用的食品添加剂。概述了一些天然的非糖类甜味剂、低热量功能性甜味剂和化学合成高倍甜味剂的种类和应用,以及它们对人类生活的影响。     

食品用复合甜味剂

文章介绍了食品用甜味剂及其复配的相关知识,指出复合甜味剂是市场发展的必然结果,高品质、营养性、安全性是未来甜味剂的发展趋势.     

几种新型的低热值高甜度甜味剂

<正> 甜味剂一般有糖类和非糖类之分。糖类中最普遍的砂糖,葡萄糖、麦芽糖、果葡糖浆等经人体摄入后会被吸收并产生热量,称之为热值性甜味剂。非糖类中的糖精、天冬甜精、甜菊苷及一些糖醇等,由于其不被人体代谢吸收,或即使参与代谢也因其甜度高、量极少而基本不产热,被称为非热值性或低热值性甜味剂。 近年来,其中糖类物质的过剩摄取引起的肥胖、糖尿病,高血脂症、龋齿等在一些     

我国功能性高倍甜味剂的发展现状与前景

甜口味剂是食品添加剂和动物饲料等行业中的一项重要产品,在世界范围内其应用量在各类食品添加剂中一直排在前列,特别是无热量.非营养性高倍甜味剂或功能性高倍甜味剂,是各国科学家研究最多的一个领域.近二十年来,肥胖症、糖尿病和龋齿等人群高发病的产生都被认为与饮食习惯及膳食结构尤其是与蔗糖摄入过多有密切关系.     

香气增甜的作用机制及评价方法研究进展

食品减糖比较常见的方法是使用非营养性甜味剂,但非营养性甜味剂会带来不受欢迎的苦味或金属味及安全风险。研究表明,在某些食物中加入香气物质可以增强人体对食品的甜味感知,即利用香气增甜作用达到食品减糖效果。从气味物质种类、甜味剂浓度2个方面总结了对香气增甜作用有重要影响的因素;从正鼻途径和后鼻途径的嗅觉感受机制、脑神经及味觉感受机制、心理感受机制3个方面阐述了香气增甜的作用机制,总结了分子模拟在分析甜味剂与味觉受体结合、释放过程的应用;归纳了评价香气增甜作用大小的感官分析方法,并比较描述性感官分析法、时间强度法和感觉时间支配分析法3种感官分析方法的差异性;对香气增甜作用在食品工业中的应用现状进行了汇总;对香气增甜研究方向以及分析气味增强味觉作用机制的方法提出展望,以期为香气减糖的研究提供新思路。     

储藏期与储藏压力对稻谷籽粒压缩特性的影响研究

利用质构仪压缩稻谷籽粒的短轴来测定稻谷籽粒的压缩特性。测定的稻谷储藏在不同的时间与压力下。实验结果表明:当储藏时间为60 d且储藏压力由0 kPa增加到300 kPa,稻谷籽粒的破坏力由81.6 N减小到73.8 N,破坏能由8.10 mJ减小到6.27 mJ,破坏应变由0.139减小到0.117,表观接触弹性模量由171.3 MPa减小到57.7 MPa,最大接触应力由40.8 MPa减小到19.1 MPa。当稻谷储藏压力为77、100、139、200 kPa且储藏时间由0～60 d,稻谷籽粒的破坏力由81.6 N分别减小到79.6、79.1、78.2、77.0 N;破坏能由8.10 mJ分别减小到7.55、7.35、7.08、6.85 mJ;破坏应变由0.139分别减小到0.131、0.128、0.126、0.121;表观接触弹性模量由171.3 MPa分别减小到136.0、121.8、110.6、83.3 MPa;最大接触应力由41.2 MPa分别减小到35.0、32.5、30.3、15.0 MPa。结果表明储藏压力与储藏时间对稻谷籽粒的压缩特性有重要的影响。     

The effect of storage pressure on the mechanical properties of paddy grains

To investigate the effect of storage pressure and storage time on the mechanical properties of paddy grains, an experimental study was carried out to determine the mechanical properties of paddy grains compressed at minor axis orientation using the Texture Analyzer. The paddy grains were stored under different pressures and for different time. The results showed that as the storage pressure increased from 0 to 300 kPa, the rupture force of paddy grains stored for 60 days decreased from 81.58 to 73.78 N, the rupture energy from 8.10 to 6.27 mJ, the rupture strain from 0.1392 to 0.1168, the apparent contact modulus of elasticity from 171.32 to 57.68 MPa and the maximum contact stress from 40.84 to 19.11 MPa. All of the mechanical properties of the paddy grains exhibited a linear relationship with storage pressure. As for the paddy grains stored under the pressures of 77, 100, 139, 200 kPa, as the storage time increased from 0 to 60 days, the rupture force of the paddy grains decreased from 81.58 to 79.58 N, 81.58 to 79.12 N, 81.58 to 78.21 N and 81.58 to 76.96 N; the rupture energy decreased from 8.10 to 7.55 mJ, 8.10 to 7.35 mJ, 8.10 to 7.08 mJ and 8.10 to 6.85 mJ; the rupture strain decreased from 0.1392 to 0.1309, 0.1392 to 0.1283, 0.1392 to 0.1257 and 0.1392 to 0.1213. The apparent contact modulus of elasticity decreased from 171.32 to 135.97 MPa, 171.32 to 121.77 MPa, 171.32 to 110.59 MPa and 171.32 to 83.32 MPa; the maximum contact stress decreased from 41.16 to 35.00 MPa, 41.16 to 32.45 MPa, 41.16 to 30.32 MPa and 41.16 to 14.97 MPa, respectively. The results revealed that both storage pressure and storage time have a significant effect on the mechanical properties of paddy grains.     

当代博物馆展陈设计表现形式的研究

为了能充分发挥博物馆的功能及满足人们对历史文化的需求,博物馆的展陈设计发挥着重要作用。同时,为了能适应世界经济的快速发展,也为了博物馆趋于可持续和完美化,当前还存在的一些问题必须解决,因此高科技的使用、多样化功能的使用、节能环保的利用等多元化元素逐渐的被引入到博物馆中。这是博物馆的需要,也是时代的需求。     

抗运动性疲劳营养补剂的研制

在体育训练和比赛中,运动员不论是在力量、速度、耐力和灵巧等方面都体现了强度大、难度高的特点,精神紧张,体力大量消耗,机体的各个系统都会发生不同的变化和反应,运动时体内激素分泌增加,物质代谢加强,能源物质被大量消耗,酸性代谢产物积聚加快,导致机体内环境发生一系列的变动。特别是在大运动量训练和激烈的比赛中,疲劳是不可避免的。这时机体对营养素的需求量必然发生某些改变。为了适应大运动量和高强度的专业化训练,仅靠平衡膳食是无法满足专业训练所消耗的大量能源物质,必须使用功能性的运动营养补剂来帮助运动员提高耐久力以及恢复体力和运动能力,以帮助运动员承受更大的训练压力和适应更大的额外训练应激,此外,运动营养补剂还可以帮助运动员提高自身内源性物质的合成水平。     

Catalysts of lipid oxidation in meat products

In emulsions consisting of refined lard, egg white and corn starch haemoglobin, initially a mixture of the oxy and met forms, at levels similar to the haemoprotein contents found in fresh meat, was a far more powerful catalyst of lipid oxidation, as measured by TBA number, than inorganic iron compounds at levels appropriate to those found in meat. This was true over the pH range 4·5 to 7·5. When added and evenly distributed to exhaustively washed muscle fibres (WF), at levels appropriate to those found in meat, haemoglobin was again a powerful catalyst, but all forms of inorganic iron appeared to have little prooxidant activity. The rate of oxidation of the lipid was very dependent on the haemoprotein concentration, being maximal in the range 10(-4) to 10(-5) M. This equates to an approximate unsaturated lipid to haem molar ratio of several hundred to one, similar to the values reported for model linoleate haem systems. In heated systems the haemoprotein again appeared to be a more effective catalyst than inorganic iron at levels appropriate to those found in meat. It is concluded that the conflicting results as to the roles of haem pigments and inorganic iron in lipid oxidation found in the literature are due, at least in part, to the difficulty of evenly dispersing the catalysts in the washed fibres, especially if heat or freezing leads to subsequent phase separation, and that H(2)O(2), formed by autoxidation of the oxypigments, may be necessary for ferric haem pigments to be effective catalysts.     

Evolution in the surface modification of textiles: a review

The development of technical textiles allows the introduction of new, interesting and original multi-functionalities in textiles through development of the architecture of fibres, yarns and fabrics, their morphology and surface functionalization without altering their physico-chemical proprieties. This issue of Textile Progress reports different techniques used to impart new functionalities to the surfaces of textiles during the last decade. Following a short, context-setting historical introduction, the preparatory processes which need to be applied to textile matrices to make them clean and ready for functionalization are examined prior to a comprehensive review of techniques and research related to the development of functional textiles ranging from the more-traditional techniques through to more-recent developments. The challenge now is to bring new performance features to bear whilst maintaining environmental sustainability, chemical toxicological acceptability, high performance and cost effectiveness. In this context, the review reports on developments in the use of polymerization, nanotechnologies, plasma treatment, electrospinning, microencapsulation and sol gel techniques to impart novel properties to a textile surface such as water-repellent, flame-retardant and antibacterial properties.     

Antibiotic resistance of Campylobacter jejuni and Campylobacter coli isolated from hog, beef, and chicken carcass samples from provincially inspected abattoirs in Ontario

Campylobacterjejuni is one of the most common causes of bacterial foodborne infection in the United States, and there are reports of resistance of Campylobacter spp. to antimicrobial agents used for the treatment of gastroenteritis. The purpose of this study was to determine the antimicrobial resistance patterns of Campylobacter spp. isolated from hog, beef, and chicken carcasses from provincially inspected abattoirs in Ontario. The agar dilution method was performed to measure antimicrobial resistance of the isolates. Antimicrobial resistance of Campylobacter isolates from hogs (n = 401), beef (n = 21), and chicken (n = 435) to ampicillin, azithromycin, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, gentamicin, nalidixic acid, streptomycin, and tetracycline was determined. Resistance of chicken, hog, and beef isolates was 14.3, 18.2, and 9.5% to ampicillin; 17.9, 67.3, and 38.1% to azithromycin; 0, 0.5, and 0% to chloramphenicol; 3.7, 1.2, and 0% to ciprofloxacin; 2.3, 46.6, and 4.8% to clindamycin; 6.7, 43.6, and 4.8% to erythromycin; 0.2, 0, and 0% to gentamicin; 5.1, 10.7, and 0% to nalidixic acid; 13.6, 57.4, and 4.8% to streptomycin; and 52.6, 44.1, 42.9% to tetracycline, respectively. The hog isolates had the greatest resistance to seven of the ten antimicrobials tested. Results of this study confirm the existence of antimicrobial resistance of Campylobacter to various antimicrobial agents,especially ciprofloxacin and erythromycin, commonly used for treatment of campylobacteriosis in humans.     

建立健全鲜活小宗农产品市场监测和调控机制的思考——基于山东省大葱、生姜的调查

通过对山东省大葱、生姜生产与流通情况的调查发现,鲜活小宗农产品市场存在供给不确定性增加,产销信息不充分、不对称,市场信息监测体系不健全,产销衔接能力不强等问题;提出了建立信息平台,探索调控思路,创新手段系统,开展试点工作,发展专业合作社,提升组织化程度,稳定葱姜生产,夯实供给基础,完善流通体系,创新产销衔接等政策建议。     

In vitro assessment of properties associated with the survival through the gastro-intestinal tract of staphylococci isolated from traditional sausage fermentation

Thirteen Staphylococcus sp. strains, previously isolated from spontaneous sausage fermentation, were in vitro examined for properties associated with their ability to survive through the gastro-intestinal tract. None of the strains were able to survive exposure to pH 1 or pH 2, while for most of them, a population reduction, ranging from 77.3% to 99.0% and a surviving population from 1.7 x 10(8) to 9.0 x 10(6) was observed after exposure to pH 3. None of the strains exhibited bile salt hydrolase activity or production of antimicrobial compounds, while all of them were resistant to pancreatin. Only S. cohnii cohnii LQC 5112 was found to be alpha-haemolytic, seven other strains were beta-haemolytic and the rest gamma-haemolytic. All strains were sensitive to erythromycin, ampicillin (but S. intermedius LQC 5023) and chloramphenicol while most of them were sensitive to tetracycline. On the other hand, most of the strains were resistant to novobiocin. Furthermore, their aptitude, not only to withstand, but to proliferate in the presence of bile salts, as well, even at an acidic environment and their ability to adhere to stainless-steel plates, indicate the need for an in vivo study.     

JDBC访问数据库的优化策略

数据库的访问方式直接影响网络应用系统的性能.为建立高性能的网络数据库应用系统,需要采用优化数据库处理的方法.优化数据库的访问,对提高网络数据库应用系统十分重要.优化要从连接开始,针对不同的应用,首先要选择合适的连接模型,以小型企业为例,一般选择模式4,在具体连接时,还可以使用连接池技术进一步改进连接性能.其次,在进行数据操作时还要使用预处理、存储过程以及优化过的SQL等来提高操作速度.使用PreparedStatement来处理SQL能大大提高系统的执行效率;在Java中利用CallsableStatement对象执行数据库中的存储过程,也具有很高的效率.