国产小麦品种麸皮结构层的定性和定量分析方法

选取6种代表性中国小麦,对麦麸结构层进行手工剥离、显微观测和特征组分分析,从而建立国产麦麸结构层的定性和定量分析方法。结果表明,国产小麦中麸皮的平均比例为18%,外果皮、中间层和糊粉层分别占22%、31%和47%;通过光学和荧光显微镜可定性判定麦麸结构层;麦麸中间层中烷基间苯二酚(ARs)的含量达11.9 mg/g,分别是外果皮和糊粉层中含量的110倍和230倍,而糊粉层中总磷的平均含量为28.7 mg/g,超过外果皮和中间层中含量的20倍。因此,ARs和磷可分别作为中间层和糊粉层的标示物,外果皮可通过计算获得。结合显微观测和标示物定量的方法,可实现全麦产品中麦麸及其结构层的添加量的快速分析。     

小麦麸皮结构层干法分离的初步研究

研究了干法分离麦麸结构层。首先对小麦麸皮进行微粉碎,通过粒径分析出麦麸粉体的粒径分散性最好的粉碎时间,利用旋振筛对此时的麦麸进行筛分,得到粒径不同的4种麦麸粉体,然后对各个麦麸粉体进行荧光定性和生化标示物定量研究。结果表明,筛分后,外皮层和中间层集中在200目筛上物的麦麸中,约占78.9%,麦麸糊粉层的细胞壁主要集中在200目筛下物和325目筛上物中,比例达41.7%,而小颗粒的麦麸糊粉层细胞内容物则集中在325目筛下物。研究初步表明,通过微粉碎和筛分的方法可以对不同麦麸结构层进行富集,为麦麸的深加工提供了一种简单的干法分离途径。     

酶法制备小麦麸皮戊聚糖的研究

采用α-淀粉酶和碱性蛋白酶分别降解小麦麸皮中的淀粉和蛋白质成为可溶性组分,通过水洗过滤分离将其除去,以制得小麦麸皮戊聚糖。在淀粉的分离提取中,通过实验分析得出最佳参数为:料液比1:12(g/ml)、加酶量0.08g、酶解时间25min、酶解温度95℃。小麦麸皮中淀粉的含量从18.6%降至0.5%以下。在蛋白质的分离提取中,通过实验分析得出最佳参数为:酶解时间4h、酶解温度40℃、固液比5%(g/ml)、加酶量1.0%。酶解后小麦麸皮中蛋白质残留量仅为0.62%。经过去淀粉和蛋白质的小麦麸皮中戊聚糖含量为34.51%。     

微粉碎对燕麦麸皮营养成分及物理特性的影响

以燕麦麸皮为原料,研究了微粉碎对麸皮营养成分及物理特性的影响.结果表明微粉碎可以提高燕麦麸皮总膳食乡维含量,但对麸皮蛋白质、脂肪、水分及灰分含量影响不大;微粉碎还可以改善燕麦麸皮的物理特性,在粒度为250～125μm时燕麦麸皮持水力最强;在180～150 μm时麸皮膨胀力最大;在150～125μm时麸皮水溶性最佳.     

不同来源小麦麸皮营养成分及酚类物质含量的比较

本文收集国内9个小麦主产省12个小麦麸皮样品,对蛋白质、总淀粉、脂肪、膳食纤维和戊聚糖,及不同形态酚类物质(游离型、可溶共价结合型、束缚型)等组分含量进行测定,采用数学统计方法对样品间组分差异和各组分相关性进行统计分析。结果表明:麸皮三大主要营养成分总膳食纤维、蛋白、总淀粉平均含量分别为47.30、19.85和16.90%,总淀粉和膳食纤维变幅较大,变异系数(CV)分别达到19.94和8.75%,蛋白变幅较小,CV值仅为3.16%,戊聚糖作为麸皮中主要膳食纤维,平均含量达到31.57%;总酚含量4470.37~5521.30μg GAE/g,73.9~79.1%为束缚型酚酸;束缚型阿魏酸在单体酚中占主导地位,含量高达2677.4~3401.8μg/g;,以下组分间存在极显著相关性(p0.01),其中膳食纤维及碱解束缚型酚酸(BBPA)与总淀粉呈极显著负相关,戊聚糖及BBPA与膳食纤维极显著正相关,戊聚糖与BBPA极显著正相关,酸解束缚型酚酸(ABPA)与总酚极显著正相关。     

丝状真菌发酵小麦麸皮中酚类物质抑制胰脂肪酶活性和HepG2细胞内甘油三酯沉积的作用

探讨了2种食品加工中常用的丝状真菌(米根霉和米曲霉)固态发酵小麦麸皮后,其总酚含量的变化,研究了发酵前后小麦麸皮中酚类物质对脂肪酶活性和Hep G2细胞内甘油三酯沉积的抑制作用。结果表明:发酵能显著提高小麦麸皮的总酚以及其抗氧化性(P0.05)。发酵后的小麦麸皮酚类物质抑制胰脂肪酶以及Hep G2细胞内甘油三酯沉积的活性均显著增强(P0.05)。未发酵、米根霉和米曲霉发酵的小麦麸皮乙酸乙酯萃取物抑制胰脂肪酶活性的IC50值分别是1.35、0.78和0.85 mg/m L。在90μg/m L质量浓度条件下,未发酵、米根霉发酵和米曲霉发酵小麦麸皮的乙酸乙酯组分对Hep G2细胞内甘油三酯沉积的抑制率分别为14.4%,26.2%和20.5%。     

响应面法优化小麦麸皮中总酚含量的测定

响应面法优化小麦麸皮中总酚含量的测定,主要考察的因素有筛分孔径、福林试剂含量、Na_2CO_3质量分数和反应温度。450~900 nm波长扫描结果确定750 nm作为多酚含量检测波长。单因素试验及响应面试验结果表明:各个单因素对总酚含量的影响从大到小的顺序依次为福林试剂含量、筛分孔径、反应温度、Na_2CO_3质量分数;小麦麸皮中总酚含量测定的最佳条件为筛分孔径9.23XX、福林试剂含量5.39 m L、Na_2CO_3质量分数14.24%、反应温度29.36℃。在此条件下,测定的小麦麸皮中总酚含量为2.044 81 mg/g。     

冲击粉碎米糠的成分变化研究

采用机械冲击粉碎对米糠进行粉碎、分级，米糠超微粉平均粒径达到7μm 以下，细胞充分破壁；并分析了其成分蛋白质、氨基酸、V_(B1)和 V_(B2)含量的增加，膳食纤维含量减少的机理。对现有的几种膳食纤维测量方法做了对比讨论。     

牡蛎壳超微粉碎工艺及粉体性质

为了探索钙添加剂的超微粉碎加工工艺及粉体性质,将牡蛎壳清洗、干燥、初步粉碎后进行超微粉碎.确定牡蛎壳超微粉碎的最佳工艺参数为:进料速度0.0625g/s,气流压力:进料压力、粉碎压力为0.56MPa,进料粒度150μm,粉碎一次.由超微粉碎得到的粉体,更易溶解于水,而且在水中的分散速度更快.     

小麦麸皮加工成食品的探讨--麸皮面粉、糊粉层面粉

介绍了发达国家低碳面粉(低碳水化合物面粉)的产生和市场的形成。探讨了可作为低碳面粉组合的麸皮面粉的制作工艺、设备。阐述了小麦籽粒的组成,减少小麦面粉碳水化合物含量的方法,麸皮面粉的主要质量指标:细度、色泽、卫生和口味;麸皮水热处理、研磨、筛分、细度测量和低碳面粉、全麦面粉的配制;从红麦麸皮提取糊粉层、微研磨和配制高蛋白面粉的方法。最后提出新产品应进行制作食品试验。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status