不同条件对蜂蜜发酵过程中高级醇生成的影响

为探究不同条件对酵母发酵蜂蜜过程中高级醇生成的影响,以蜂蜜、麦曲、酵母为原料,以高级醇含量为指标,通过单因素试验分别考察了发酵温度、酵母添加量、发酵时间、磷酸氢二铵添加量和发酵液糖度对酵母发酵蜂蜜过程中高级醇生成的影响。响应面优化结果表明,当麦曲添加量为4%,干酵母的加入量为0.2%,磷酸氢二铵添加量600 mg/L,起始发酵液的糖度为30.0%,pH为4.5,培养温度为34℃,培养时间为4 d,在此条件下得到高级醇的最低值43.72 mg/L。     

响应面法优化红曲调味酒的发酵条件

为探究不同条件对红曲调味酒发酵的影响,以蜂蜜、红曲、酵母为原材料,以高级醇含量为指标,通过单因素试验分别考察了发酵温度、发酵液pH值、酵母添加量、发酵时间、磷酸氢二铵添加量和发酵液糖度对酵母发酵蜂蜜过程中高级醇生成的影响。响应面优化结果表明,红曲调味酒的最佳优化条件为:培养温度为28℃,培养液pH为5,红曲米添加量为4%,酵母添加量为0.2%,糖浓度为25.4%,磷酸氢二铵的添加量为1000mg/L,培养时间为6d。     

葡萄冰酒干酵母R2发酵冰荔枝酒工艺条件的优化

以冻藏荔枝经低温榨取或低温浓缩后的荔枝汁为原料,利用葡萄冰酒干酵母R2发酵酿制冰荔枝酒,研究了发酵温度、接种量、SO2添加量、起始糖和酸含量、硫酸铵添加量等因素对发酵的影响。通过正交试验确定了冰荔枝酒最佳的发酵条件为发酵温度10℃、SO2添加量100mg／L、起始糖度330g／L、硫酸铵添加量600mg／L、起始酸含量为7．7g／L、接种量为375mg／L。可生产酒精体积分数为10％-12％的冰荔枝酒,产品呈金黄色,清亮透明,果香浓郁,丰满醇厚,甜润爽口,具有较好的类似于葡萄冰酒的品质。     

蜂蜜酒发酵工艺条件的优化研究

以蜂蜜、麦曲、酵母为原材料,以酒精度为指标,通过单因素实验分别考察了发酵温度、发酵时间、磷酸氢二铵添加量和发酵液糖度对酵母发酵蜂蜜过程中酒精度的影响。根据响应面优化结果进行验证实验,最终的优化条件如下：当麦曲添加量4.0%,酵母添加量0.2%,磷酸氢二铵添加量600 mg/L,发酵液糖度为32.0%,pH值为4.5,发酵温度为32.0 ℃,培养时间为6 d时,能得到酒精度的最高值13.6%。     

红心猕猴桃果酒酿造工艺研究

以红心猕猴桃为原料,研究其果酒的发酵工艺条件。采用单因素实验和正交实验,分别考察了果胶酶添加量、SO_2添加量、酵母菌接种量以及初始糖度等因素对果酒发酵的影响。结果表明,红心猕猴桃果酒的最佳发酵条件为:果胶酶添加量0.09 g/L、SO_2添加量0.09 g/L、酵母菌接种量1.5%、初始糖度210 g/L。由此得到的红心猕猴桃果酒呈淡红色,酒体醇厚,果香浓郁。     

响应面法优化牡蛎多糖低醇无花果酒发酵工艺

以山东荣成青皮无花果为原料,添加牡蛎多糖,制备低醇无花果酒。采用单因素试验及响应面试验设计,探究发酵时间、初始糖度、酵母菌接种量、牡蛎多糖添加量、发酵温度对其酒精度和感官评分的影响,并优化牡蛎多糖低醇无花果酒发酵工艺。结果表明,最佳发酵工艺为：发酵温度25 ℃,发酵时间7 d,初始糖度17 °Bx,pH 3.50,酵母菌接种量0.05%,牡蛎多糖添加量0.3%。在此优化条件下,牡蛎多糖低醇无花果酒酒精度为7.17%vol,牛磺酸含量为482 mg/L,Zn含量为13.3 mg/L,感官评分为94.2分。     

黄秋葵蔬菜酒发酵工艺研究

以黄秋葵为原料,添加果酒酵母发酵成蔬菜酒。实验对影响黄秋葵发酵酒品质的工艺条件进行了研究,通过对温度、糖度、接种量、柠檬酸添加量等因素进行单因素实验,选取合适的水平,以感官评分作为实验指标进行L_9(3~4)正交实验。将正交实验的结果进行极差、方差分析,结果表明,温度28℃、糖度18%、接种量0.135 g/L、柠檬酸添加量8 g/L为最佳工艺参数,接种量和发酵温度在实验的各因素中为显著因素。     

橘子酿造酒发酵工艺参数的探讨

以湖北本地橘子为原料,榨汁和调整糖度后,用果酒酵母发酵生成橘子酒,研究偏重亚硫酸钾添加量、发酵温度、接种量等因素对发酵周期和酒度的影响。单因素和正交实验得出柑橘发酵酒最佳工艺:偏重亚硫酸钾添加量为100mg/L,发酵温度15～20℃,活性干酵母接种量7%。     

荔枝酒中游离SO2与总SO2的关系研究

果酒中所添加的SO2以游离态和结合态两种形态存在,其中游离SO2主要起抑制杂菌、抗氧化等作用.在荔枝酒中,不管总SO2含量多少,游离SO2含量均在4～8 mg/L.本文探讨了荔枝酒中游离SO2偏低的原因,并研究了通过添加N源营养素来增加游离SO2的含量.实验结果表明,添加磷酸氢二铵或硫酸铵,能将酒中游离SO2占总SO2的比率从4.0%提高到17.5%左右,在总SO2一定的情况下,增加了游离SO2的量,为生产中减"S"提供理论依据.     

榴莲果酒发酵工艺优化及其香气成分分析

研究酵母添加量、初始糖度、SO_2添加量和pH值对榴莲果酒发酵的影响,确定果酒发酵的最佳工艺条件,并采用气相色谱—质谱(GC-MS)联用技术分析榴莲果酒香气物质。结果表明:榴莲果酒发酵的最佳工艺为酵母添加量0.7%,初始糖度28%,SO_2添加量60mg/L,pH值3.6。通过GC-MS对榴莲果酒香气成分进行分析,鉴定出22种香气成分,其中以醇类物质相对含量最高,酯类物质种类最多。     

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.