衰减全反射傅里叶变换红外光谱测定米粉中硒代甲硫氨酸的含量

利用衰减全反射傅里叶变换红外光谱法测定米粉中硒代甲硫氨酸含量,以期探寻一种快捷、绿色环保的食品中硒含量的测定方法。通过采用添加硒代甲硫氨酸制备样品,衰减全反射中红外光谱仪采集红外光谱,TQ Analyst分析软件进行偏最小二乘法建模并验证,结果表明,选择1 600～650 cm－1作为样品的红外光谱分析波段,用导数对原始红外光谱处理后,采用留一和留多两种方法均获得良好的预测效果。比较而言,一阶导数处理后的留一模型,计算简单且预测效果更好。留一模型的决定系数RC 2 均大于0.997,因子数均为6,校正均方差为1.76～1.9,留一验证预测决定系数RP2为0.986 8,预测均方差为3.27,相对分析误差为8.612 9,预测值相对偏差在20%以内的占92.91%,10%以内占82.27%。     

衰减全反射中红外光谱测定马铃薯中可溶性蛋白含量

傅里叶变换衰减全反射红外光谱法是一种快速无损绿色的分析技术,结合化学计量学和数学建模可对混合物进行定性、定量分析。本研究利用衰减全反射中红外光谱建立测定马铃薯中可溶性蛋白含量的方法,以满足选育高蛋白质含量马铃薯的快速测定,提高快速鉴定育种品系品质的目的。采用平滑降噪和导数基线矫正的方法预处理数据,选择1 700～600 cm~(-1)波段作特征光谱,提取主成分并逐步回归建模。结果表明7点平滑后一阶导数处理数据,能较准确地测定马铃薯中可溶性蛋白的含量,对于验证集的预测,其中70. 37%预测值偏差小于20%,对于鲜重蛋白质含量在5 mg/g以上的14个样品的预测,高达92. 86%预测值偏差小于20%,说明能准确快速鉴定高蛋白品系。     

衰减全反射红外光谱测定番茄酱中番茄红素

利用衰减全反射红外光谱法测定番茄酱中番茄红素,选择1 700~950?cm-1作为样品的红外光谱分析波段,用二阶导数对原始红外光谱降噪后,进行偏最小二乘法回归分析,建立了回归方程,模型决定系数R2为0.970。经验证,其相对预测均方根误差为3.78,预测值与真实值的线性拟合决定系数为0.959 8,能较准确测定番茄酱中番茄红素含量。     

基于负二阶导数红外光谱的反式脂肪酸的快速测定

建立了基于负二阶导数红外光谱的反式脂肪酸的快速测定方法。以三反油酸甘油酯和三油酸甘油酯混合标样系列为校正集,使用带有水平衰减全反射(HATR)附件的傅里叶变换红外光谱仪采集校正集样品在1 050～900 cm-1波段范围的吸收光谱,求二阶导数,乘以-10 000,得负二阶导数谱(-2D-HATR-FTIR)。以970～960 cm-1波段范围的最大峰高为X轴,以三反油酸甘油酯含量为Y轴,构建定标方程为Y=0.348 8X-0.918 5,相关系数0.999 5。在0.5%～60%范围,验证集样品反式脂肪酸含量预测值与实际指定值显著相关,验证相关系数0.999 0,相对残差的绝对值小于10%,表明方法定标模型预测性能良好。方法检测下限达0.5%,改善了现有红外光谱法的灵敏度,适用于较低含量反式脂肪酸的快速测定。     

黄海牡蛎中锌和硒含量的测定与健康保健食用量分析

采用原子吸收光谱法测定黄海海域牡蛎中有益元素锌的含量,通过催化动力学吸收光度法测试了有益元素硒的含量。以上两种方法均具有较高的灵敏度和准确度,样品的回收率分别在98.8%～101.0%和98.4%～100.8%之间,其变异系数分别为6.53%和2.98%,且操作过程简便快捷,适用于不同样品的对照性实验。黄海牡蛎中锌含量达162.68μg/g,硒含量达0.6464μg/g,测定结果表明,每天食用湿重100g左右的黄海牡蛎可满足人体内对生物锌和硒的需求。     

氢化物发生-原子荧光光谱法测定富硒麦芽中的硒含量

建立了氢化物发生-原子荧光光谱法测定富硒麦芽中硒的分析方法.研究了仪器的工作条件、试剂对硒测定的影响,探讨了消化试剂对样品消化的影响和共存离子的干扰及消除.在优化的工作条件下,硒的检出限(σ=3)为0.167μg/L,相对标准偏差(RSD)为1.203%,线性范围为0～100μg/L.应用该方法测定了不同富硒麦芽中的硒含量为11.729～32.746μg/g,加标回收率为94.1%～101.6%.     

基于水平衰减全反射傅里叶变换红外光谱的食品中反式脂肪酸的测定

目的:建立基于水平衰减全反射傅里叶变换红外光谱的食品中反式脂肪酸的快速测定方法.方法:负二阶导数水平衰减全反射傅里叶变换红外光谱法(-2D-HATR-FTIR).使用带有水平衰减全反射(HATR)附件的傅里叶变换红外光谱仪,采集三反油酸甘油酯标样在l 050～900 cm-1波段范围的吸收光谱,并求得负二阶导数谱.根据反式脂肪酸中孤立的反式双键在966 cm-1处的特征吸收与混合标样中反式脂肪酸的含量符合比尔定律的原理,构建定标方程.根据定标方程测定食品样品中反式脂肪酸含量.结果:在试验条件下,定标方程为Y=3 359.2X-0.6175,相关系数0.9997,检出限0.27％,回收率78.06％～112.65％.食品中反式脂肪酸含量最高接近50％.结论:建立一种新的快速测定食品中反式脂肪酸的方法,该法准确可靠,快速、简便,克服了现有红外光谱法灵敏度低的缺点,适用于食品中较低含量反式脂肪酸的快速测定.     

蜂蜜中还原糖组分的近红外光谱应用研究

为探索快速测定还原糖含量的方法,提出了用傅立叶变换近红外光谱技术结合偏最小二乘法(PLS)建立近红外光谱与蜂蜜还原糖含量的数学模型并进行预测。通过光谱扫描还原糖含量在61.3%～75.22%范围的蜂蜜样本,选择11992.1～7494.6cm-1波数范围、二阶导数、及10个因子数进行光谱预处理,偏最小二乘法(PLS)交叉验证。结果表明,模型的校正决定系数(Rcal)、校正均方差(RMSEE)、交叉验证决定系数(RCV)、交叉验证均方差(RMSECV)分别为99.71%、0.27%、98.44%、0.45%。用该模型对验证集样本进行预测并统计分析,表明预测值与测定值无显著差异。因此,用该方法快速准确定量分析大批蜂蜜中的还原糖含量具有重要意义。     

禽蛋硒的含量检测及其营养特性

检测禽蛋硒的含量并探讨其作为硒来源或富硒食品的可能性。采用微波消解仪消解样品,氢化物发生原子荧光光谱测定禽蛋的硒含量,方法检测限为1.6μg/100 g,回收率为91.3%¹04.1%,精密度为1.6%104.1%,精密度为1.6%³.8%。4种禽蛋的硒含量在13.33.8%。4种禽蛋的硒含量在13.3²3.6μg/100 g,蛋黄的硒含量在26.623.6μg/100 g,蛋黄的硒含量在26.6³2.5μg/100 g,每种禽蛋蛋黄的硒含量约为蛋清硒含量的4倍;4种禽蛋的硒含量从大到小依次为鹅蛋、鹌鹑蛋、鸭蛋、鸡蛋;鸭蛋、鸡蛋硒的营养素参考值%均大于15%,是硒来源,或含有硒食品;鹅蛋、鹌鹑蛋硒的营养素参考值%均大于30%,是高,或富含硒的食品;4种禽蛋蛋黄的营养素参考值%均大于30%,是高,或富含硒食品。     

ATR-FTIR结合化学计量学鉴别猪牛羊革的研究

利用衰减全反射傅里叶变换红外光谱(ATR-FTIR)技术采集猪、牛、羊革样品的红外光谱信息,分析皮革红外光谱特征。通过化学计量学对光谱数据进行处理,选择合适的光谱区域和预处理方法,建立定性鉴别皮革种类的判别分析模型(Ⅰ和Ⅱ)及方法。根据计算得到的马氏距离,由模型I对样品"牛/羊"和"猪"革种类进行判别,然后由模型Ⅱ进一步对"牛"和"羊"革种类进行判别。通过验证集样品对模型性能进行评价,结果表明模型Ⅰ对猪革判别正确率为100%;由于牛、羊革的光谱信息极为相似,模型Ⅱ判别正确率有所降低。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.