酶-物理法提取木薯渣中膳食纤维的工艺研究

对干木薯渣进行物理粉碎,再用α-淀粉酶和糖化酶(中温淀粉酶60℃~70℃)、脂肪酶和风味蛋白酶除去木薯渣中的淀粉、脂肪和蛋白质,得到纯净的木薯膳食纤维并用超声波辅助脱色;通过单因素试验得到了木薯渣化学成分去除率和膳食纤维脱色的最佳工艺条件。化学成分去除的最佳工艺条件为:当α-淀粉酶和糖化酶的质量比1∶6,用量为0.6%,酶解pH=7,酶解时间为120 min,酶解温度为60℃时,淀粉去除率最高;当脂肪酶用量0.21%,酶解pH=7,酶解时间90 min,酶解温度为50℃时,脂肪去除率最高;当风味蛋白酶用量0.6%,酶解pH=4,酶解时间150 min,酶解温度为35℃时,蛋白质去除率最好。脱色的最佳试验条件为:当H2O2浓度为10%,漂白时间40 min,超声功率为60 W,漂白温度50℃时,漂白效果最好。     

双酶法提取小麦麸皮膳食纤维的工艺研究

以小麦麸皮为原料,采取双酶提取法制备小麦麸皮膳食纤维,通过正交实验得出最佳提取条件为:α-淀粉酶添加量为0.6%,α-淀粉酶酶解pH为6,α-淀粉酶酶解温度为70℃,碱性蛋白酶添加量为0.3%,碱性蛋白酶酶解pH为9,碱性蛋白酶酶解温度为55℃,此时小麦麸皮膳食纤维提取率为71.94%。     

正交试验优化酶法提取菜籽皮不溶性膳食纤维工艺

目的：以菜籽皮为原料,研究不溶性膳食纤维的酶法提取工艺条件。方法：采用淀粉酶和蛋白酶酶解菜籽皮,以不溶性膳食纤维得率为指标,通过正交试验优化最佳工艺条件。结果：淀粉酶加酶量0.7%,料液比1:20、pH5.5、温度40℃、酶解时间60min,在此条件下菜籽不溶性膳食纤维得率为81.24%;蛋白酶的添加量0.7%、料液比1:20、pH7.5、酶解温度40℃、酶解时间60min,在此条件下菜籽不溶性膳食纤维得率为77.13%。结论：确定了影响膳食纤维提取的主要影响因素,得到了菜籽皮不溶性膳食纤维酶解法提取的最佳条件。     

荞麦膳食纤维的研制

报道了以荞麦为原料,对荞麦壳申膳食纤维的提取及脱色工艺进行的研究.采用化学法和酶法分别制备荞麦膳食纤维,并对所得膳食纤维进行脱色.通过试验分别得到,化学法提取荞麦壳膳食纤维最佳工艺为:pH 5.0,反应温度为55℃时,NaOH质量分数为4%,水解时间60min;酶法提取荞麦壳膳食纤维最佳工艺为:pH 7.0±0.2时,蛋白酶质量分数为0.2%,反应时间60 min.两种方法比较得出,酶法提取效果较好.脱色最佳工艺为:pH 11,H2O2体积分数为4%,温度为90℃,反应时间为90 min.     

酶法提取花生粕不溶性膳食纤维的研究

以花生粕为原料,采取酶法提取花生粕中的不溶性膳食纤维,探讨α-淀粉酶、木瓜蛋白酶最佳酶解条件。结果表明:α-淀粉酶的最佳酶解条件为温度60℃,时间30 min,pH4.0,酶量2%;木瓜蛋白酶的最佳酶解条件为温度80℃,时间2 h,pH7.0,酶量11%,花生粕不溶性膳食纤维的提取率达到37.72%。     

胡萝卜渣膳食纤维提取工艺及其性能特性研究

通过水提醇沉法提取胡萝卜渣水溶性膳食纤维(CRSDF),通过外加淀粉酶和蛋白酶提取胡萝卜渣水不溶性膳食纤维(CRIDF),采用均匀设计优选提取工艺条件;通过测定CRIDF的膨胀性、持水力、结合水力、阳离子交换容量、结合脂肪能力及吸附胆酸钠能力来了解其性能特性.CRSDF提取的最佳工艺参数为时间60 min,液料比40:1(mL/g),pH值1.5,温度80%;提取率为70%.最佳酶解条件,淀粉酶为加酶量0.60%,时间60 min,pH值7.0,温度75℃;中性蛋白酶为加酶量0.30%,时间60 min,pH值7.0,温度70℃.利用胡萝卜渣提取膳食纤维得率较高,理化性能较好,有良好的发展前景.     

影响麦麸膳食纤维得率的因素分析

以麦麸为原料,采用生物法制备膳食纤维。正交实验结果表明,提取膳食纤维的最佳工艺参数为:混合酶制剂的用量为0.2%,α-淀粉酶∶糖化酶=1∶3,酶解时间30min,混合酶解温度65℃;蛋白酶用量为0.3%,酶解时间60min,酶解温度60℃。在此工艺条件下,纤维素得率为66.26%,成品呈淡黄色,气味淡。其溶胀性达6.88ml/g,持水力为7.3581%。     

酶法提取高品质浒苔膳食纤维工艺

以浒苔为原料,对浒苔膳食纤维提取和漂白工艺条件进行探讨;通过正交试验设计确定酶法提取膳食纤维和漂白的最佳条件。酶法提取膳食纤维的最佳条件,蛋白酶处理的温度为25℃、pH5、用酶量1%、时间为60min;α-淀粉酶处理的温度为30℃、pH6、用酶量0.1%、时间为20min;最佳漂白条件,漂白液浓度0.80%、pH6、漂白时间10min。在此条件下,提取率为40.22%、膨胀力为45.13mL/g、持水力为2171%。产品可作为高品质膳食纤维及理想的食品添加剂。     

茭白壳膳食纤维提取工艺及性能的研究

以芟白壳为原料,采用化学法制备可溶性膳食纤维和不溶性膳食纤维.正交实验结果表明,可溶性膳食纤维提取的最佳工艺条件为:pH2.0、温度80℃、时间90min.不溶性膳食纤维提取的最佳工艺条件为:碱解时NaOH浓度1.0mol/L、料液比1:20(g/mL)、温度60℃、时间60min;酸解时pH3.0、温度60℃、时间120min,其溶胀性为4.34mL/g,持水力为8.11g/g.     

双酶法分离提取米糠膳食纤维的研究

米糠是稻谷加工的副产物之一,其中米糠膳食纤维含量高达35%~50%,是理想的膳食纤维来源。实验研究了双酶法分离提取米糠膳食纤维的最佳工艺条件,并对所提膳食纤维的基本成分进行了分析。根据正交实验结果表明,提取米糠膳食纤维时,除淀粉的最佳条件为:耐高温淀粉酶,酶解时间3.5 h,酶解温度75℃,酶用量20μL;除蛋白的最佳条件为:碱性蛋白酶,酶解时间2.5 h,酶解温度60℃,酶用量2%。在最优条件下分离提取得到的米糠膳食纤维:总膳食纤维、不溶性膳食纤维和可溶性膳食纤维纯度分别为87.26%、68.23%和3.99%。根据扫描电镜结果显示,不溶性和可溶性膳食纤维表面均具有明显的蜂窝状结构。     

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.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.