乳酸菌发酵法制备茶渣可溶性膳食纤维的工艺研究

以茶渣为原料,采用保加利亚乳杆菌和嗜热链球菌(1:1)混合菌为发酵菌种,研究以微生物发酵法制备茶渣可溶性膳食纤维(SDF)的最佳工艺参数.通过单因素实验,探讨了接种量、发酵温度、发酵时间和料液比等因素对发酵工艺的影响,利用L9(34)正交实验对茶渣SDF的制备工艺进行优化.结果表明:发酵法制备茶渣SDF的最佳工艺条件为:接种量为3％,发酵温度40℃,发酵时间25h,料液比1∶10(g/mL),在此条件下得到的茶渣SDF的平均得率可达10.99％.     

海鲜菇乳酸饮料生产工艺研究

以海鲜菇、绵白糖为主要原料,采用复合发酵剂(保加利亚乳杆菌和嗜热链球菌,质量比1∶1)对其进行发酵,研制海鲜菇乳酸饮料。采用单因素和响应面试验对影响饮料的主要因素进行优化。结果表明:当液料比10∶1(mL/g)、接种量6%、发酵时间13.86 h、发酵温度42.5℃时,海鲜菇乳酸饮料感官评分最高,为94.25分,在此条件下,海鲜菇乳酸饮料酸度适宜,口感较好。影响海鲜菇乳酸饮料感官评分因素由大到小依次为发酵温度接种量液料比发酵时间。     

生米制醋中液态酿酒工艺因素优化

对生米酿酒工艺中发酵的温度、糖化酶用量、活性干酵母用量、料水比、乌衣红曲用量、不同的糖化发酵剂、不同的大米原料进行了单因素的优化试验.确定最佳工艺因素为:发酵温度25℃～30℃,糖化酶用量0.45％(酶活5×104U),活性干酵母用量0.3％,料水比1∶2.5倍,乌衣红曲用量3％,糯米原料较优.并选择3个重要的单因素进行正交优化验证.液态生米酿酒原料出品率可达到300％(15％vol酒精度).     

基于响应面法优化红豆米酒发酵工艺的研究

以生料曲为糖化发酵剂,红豆、红米为原料混合发酵进行生料酒的酿制。在单因素试验的基础上,选取物料比(红豆∶红米)、料液比、接种量及发酵温度为影响因素,以感官评分为响应值,采用Box-Behnken中心组合试验设计建立数学模型,进行响应面分析。结果表明,红豆米酒最优的酿造工艺条件为:物料比1∶2.9(g∶g)、料液比1∶3(g∶mL)、接种量2.1%、发酵温度29℃,在此条件下红豆米酒的感官评分为90.9分。     

响应面分析法优化山杏仁多肽发酵制备工艺条件

以山杏仁饼为原料,经脱脂后通过黑曲霉发酵制备山杏仁多肽,对发酵工艺条件进行了优化.在单因素实验的基础上,采用四因素三水平的响应面法对影响山杏仁多肽含量的4个主要因素,即液料比、初始pH、接种量和发酵温度进行分析优化.结果表明,山杏仁多肽发酵制备工艺的最佳条件为:初始pH6.4,液料比12∶1,接种量10.5％,发酵温度30℃.在此条件下,测得山杏仁多肽含量为4.768 mg/mL,与理论预测值的相对误差为1.058％.     

木薯生料发酵制备燃料乙醇的工艺条件研究

试验对木薯生料发酵制备乙醇的工艺条件进行了优化研究,对影响发酵过程的生料淀粉水解酶用量、料液比、发酵初始pH和发酵温度四个因素在单因素试验的基础上进行了正交试验优化,得到最佳发酵条件为生料水解酶用量4 mL/kg,料液比1∶3.5,初始pH4.5,发酵温度37℃,根据优化条件进行验证试验,总糖消耗率与淀粉利用率分别为83.29%和79.80%,但与低温水解发酵工艺相比尚有一段距离。     

薯莨保健酒的研制

以糯米和薯莨为原料生产薯莨保健酒,通过单因素试验选取原料配比、料液比、酵母添加量、发酵温度为主要因素,采用Box-Benhnken响应面分析法对选取的主要因素进行回归分析,确定了发酵产薯莨保健酒的最优工艺条件为:A(原料配比)薯莨:糯米为1:0.3,B(酵母接种量)为0.4%,C(料液比)为1:0.6,D(发酵温度)为30℃。     

正交试验优化咂酒半固态发酵工艺的研究

为了优化咂酒半固态发酵工艺,该试验以青稞为原料,基于单因素试验结果,以黄曲麸曲用量、发酵用水量、前发酵温度和后发酵时间为考察因素,设计了4因素3水平正交试验。结果表明:咂酒半固态发酵工艺最佳条件为:麸曲用量10%、料液比1∶2.0(w/v)、前发酵温度27℃、后发酵时间为7d。在此条件下所产咂酒口感好、酒体醇厚、质量优异。     

发酵法制备刺梨果渣可溶膳食纤维的工艺优化

为研究刺梨果渣可溶性膳食纤维的发酵工艺,该文以保加利亚乳酸杆菌与嗜热链球菌1:1混合菌种为发酵剂,在接种量、发酵时间、发酵温度、pH和料液比5个单因素实验的基础上,利用正交实验对可溶性膳食纤维的制备工艺进行优化。结果表明:该法制备刺梨果渣可溶性膳食纤维的最佳工艺条件为:接种量12%、pH6.0、发酵时间48 h、料液比1:25、发酵温度40℃。在此条件下明显提高了刺梨果渣可溶性膳食纤维的比例,其得率为16.81%,经发酵法制备的刺梨果渣膳食纤维持水力和膨胀力均高于刺梨果渣。     

甘薯淀粉传统工艺优化

采用极差分析法,对甘薯淀粉生产发酵条件各因素的K、k及R值(极差)的大小进行分析.结果表明,料液比是影响淀粉得率的最主要因素,其次为发酵时间,最后是发酵温度、分离时间.通过单因素试验和L9(34)4因素3水平正交试验,以淀粉得率为标准,确定甘薯淀粉发酵最佳工艺为:料液比1 ∶ 5、分离时间12h、发酵温度为15℃、发酵时间48h.     

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.