高温蒸煮结合酶解改性豆渣膳食纤维

采用高温蒸煮结合纤维素酶酶解的方法,改性豆渣不溶性膳食纤维,制备水溶性膳食纤维。以水溶性膳食纤维的得率为考察指标,分别对高温蒸煮改性、高温蒸煮结合纤维素酶酶解改性工艺进行研究,并应用正交试验设计法优化高温蒸煮结合纤维素酶酶解改性工艺。结果显示,在优化的高温蒸煮结合纤维素酶酶解改性的反应条件下,即固液比为1:20 g/mL、酶解温度为45℃、酶底比为0.3%、酶解时间为4 h、pH值为5.0时,改性后水溶性膳食纤维的得率为31.89%,明显高于单独采用高温蒸煮法(130℃、60 min)改性的水溶性膳食纤维得率(10.85%)。     

复合纤维素酶法制备玉米水溶性膳食纤维

以玉米皮水不溶性膳食纤维为原料,对复合纤维素酶法制备水溶性膳食纤维(SDF)进行了研究。采用六偏磷酸钠及高温蒸煮等处理方法强化酶解过程以提高水溶性膳食纤维得率。结果表明,高温蒸煮有助于提高玉米皮水溶性膳食纤维得率,条件为121℃,3 h。在单因素实验的基础上,采用L9(34)正交实验对复合纤维素酶法制备水溶性膳食纤维的条件进行优化。结果表明,玉米水溶性膳食纤维的较佳提取条件为:复合纤维素酶的添加量2%,底物浓度40 g/L,酶解温度55℃,pH4.0,酶解11 h。在此条件下,玉米SDF得率达到10.37%。     

生物酶法改性玉米皮渣膳食纤维工艺研究

该研究以玉米皮渣为原料,经处理后获得不溶性膳食纤维,采用生物酶法对膳食纤维进行改性处理,主要研究双酶酶解工艺对水溶性膳食纤维得率的影响。结果表明,木聚糖酶和纤维素酶酶解玉米皮渣可显著提高可溶性膳食纤维得率,最佳的酶解条件为纤维素酶添加量为30 mg/g底物、木聚糖酶添加40 mg/g底物、料液比1∶12（g/mL）、酶解时间90 min,在该条件下,水溶性膳食纤维得率为2.996%。     

双酶改性制备玉米皮水溶性膳食纤维的工艺研究

以玉米皮超声提取天然水溶性膳食纤维后的副产物——不溶性玉米皮渣为试材,应用木聚糖酶和纤维素酶组合酶解制备水溶性膳食纤维,采用单因素和正交试验组合研究确立一套由水不溶性膳食纤维改性制备水溶性膳食纤维制备工艺。结果表明,最佳工艺参数为纤维素酶添加量40mg/g 底物、木聚糖酶添加量40mg/g 底物、料液比1:14(g/ml)、酶解时间90min,水溶性膳食纤维得率为5.96%。     

豆渣可溶性膳食纤维酶法制备工艺及其品质分析

为了获得高得率的豆渣可溶性膳食纤维,以碱处理豆渣制备可溶性膳食纤维后剩余的不溶性残渣为原料,采用纤维素酶对其进行酶解改性。通过单因素试验和响应面优化试验,研究了不同酶解条件对豆渣可溶性膳食纤维得率的影响。结果表明:对豆渣可溶性膳食纤维得率的影响因素依次为加酶量>酶解时间>酶解温度>酶解pH,最佳酶解工艺条件为:加酶量1.80%,酶解时间3.5 h,酶解温度48℃,酶解pH4.8。在此条件下,豆渣可溶性膳食纤维得率可达到7.64%,且其品质符合国家粮食行业标准规定的指标。扫描电镜结果表明,酶法制备的豆渣可溶性膳食纤维的颗粒较小,呈现蜂窝状,有利于其水合特性的提高。     

酶法制备豆渣水溶性膳食纤维

采用酶法从豆渣中提取水溶性膳食纤维,对四种纤维素酶进行了筛选,并确定了最佳酶制剂.研究了料水比、纤维素酶的添加量、反应时间、反应温度和溶液pH 5个因素对水溶性膳食纤维提取量的影响,通过单因素和正交实验,确立了制备水溶性膳食纤维的最佳工艺条件.在此工艺条件下,水溶性膳食纤维的得率为10.45%.     

玉米皮水溶性膳食纤维的酶法制备

本研究采用复合纤维素酶和木聚糖酶对经过处理的玉米皮进行酶解,制备玉米皮水溶性膳食纤维(SDF),通过单因素和正交试验确立了一套最佳制备工艺。结果表明,复合纤维素酶和木聚糖酶混合改性制备SDF的最佳工艺参数为:酶添加量0.8%、酶解温度58℃、酶解pH 5.5、酶解时间8 h,SDF得率为13.82%。本方法中,玉米皮表面蛋白和淀粉杂质去除比较充分,产品纯度和得率高,工艺简单,适应工业化生产,得到的SDF产品黏度低、持水力及溶胀性好。     

木聚糖酶改性玉米麸皮膳食纤维粉工艺研究

以玉米麸皮为原料制备膳食纤维粉,采用木聚糖酶对其进行改性,以提高膳食纤维品质。通过木聚糖酶法,可溶性膳食纤维得率为27.49%;其最适反应条件为:木聚糖酶添加量25.7 U/g、酶解时间1.96 h、酶解温度56.09℃、酶解pH 4.68。     

酶法制取玉米水溶性膳食纤维的研究

采用纤维素酶和木聚糖酶对脱去淀粉和蛋白质的玉米皮进行处理, 以得到水溶性膳食纤维.通过正交试验探究酶解过程的最佳工艺条件,从而提高不溶性膳食纤维的转化率.结果表明,在温度为45℃、pH值为4.8、料液比为1:12、酶解时间为8h、纤维素酶和木聚糖酶的添加量分别为1%和0.3%时,转化率最高,可以达到6.57%.其中,纤维素酶的添加量对试验影响显著性最大.     

以大豆皮为原料酶法制备水溶性膳食纤维工艺研究

研究了以大豆皮为原料酶法制备水溶性膳食纤维（SDF）的工艺,并对影响SDF得率的主要因素进行了探讨。结果表明,影响SDF得率的主要因素依次为酶解时间、pH、酶添加量、酶解温度;通过正交试验得到优化工艺条件为酶解时间18h,pH4,酶添加量2．5％,酶解温度50℃。在优化条件下,SDF得率为11．84％,纯度高达76．08％。     

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.