响应面法优化火龙果酒发酵工艺及其鸡尾酒的调配

以火龙果汁为主要原料,采用响应面法优化火龙果酒的发酵工艺,对起始糖度、起始pH值、发酵温度、菌种接种量等因素进行单因素试验,在此基础上进行响应面优化设计。结果表明,火龙果酒发酵的最佳工艺条件为起始糖度22.6%、起始pH值3.6、发酵温度15℃、酵母接种量1.0%,在此优化条件下,火龙果的感官评分为88.64分。再以火龙果酒为基酒,配以火龙果汁15%、白糖水25%,调配出品火龙果鸡尾酒。该饮品口感较佳,营养丰富,含有维生素、微量元素,具有一定的保健功效。     

不同酵母发酵的火龙果酒抗氧化活性及颜色变化

研究4种不同酵母发酵的火龙果酒在发酵过程中总酚、甜菜苷、抗氧化活性和颜色的变化规律。结果表明,在发酵过程中,4种酵母发酵火龙果酒的总酚、甜菜苷含量均呈下降趋势;L*值、a*值均升高,b*值降低。酵母RC212发酵的火龙果酒的多酚含量最高为272.5 μg/mL,其对DPPH自由基清除率IC50最低为22.98%;酵母R2发酵的火龙果酒的羟自由基清除率、总还原力IC50最低,分别为8.84%、28.52%,并且甜菜苷含量最高为581.4 mg/L。酵母RC212与酵母R2发酵的火龙果酒在抗氧化物质含量、抗氧化活性及红色素稳定性方面均优于酵母DV10与酵母D254发酵的火龙果酒。     

红芯火龙果酒酿酒酵母的筛选

以筛选适宜的酿造火龙果酒的酵母为研究目标,采用产于广西和浦县的第3代红皮红肉火龙果为原料,对经初选后得到的4种商业酵母(R2、RC212、D254、DV10)分别进行耐SO2能力、发酵糖能力和耐糖能力的研究.分析不同SO2浓度和糖浓度下酵母的降糖能力和酵母菌的生长繁殖情况,并通过综合评价筛选出酵母R2为较适合红芯火龙果酒发酵的酵母.     

4种商用酿酒酵母发酵火龙果酒的发酵动力及成分变化

4种商业酿酒酵母R2、D254、DV10和RC212用来评估其对红芯火龙果酒的发酵动力及发酵过程中产生的非挥发性以及挥发性成分的影响。结果表明,不同酵母对火龙果酒发酵及成分的影响不同。RC212酵母与R2酵母具有更快的发酵速率;R2酵母发酵的火龙果酒酒精度为11.47%vol、甜菜苷含量为581.44 mg/L、多酚含量为272.52μg/m L,显著高于其他3种酵母发酵的火龙果酒。清汁发酵的火龙果酒主要有机酸为苹果酸和琥珀酸,带渣发酵的则为琥珀酸、苹果酸和柠檬酸。挥发性香气成分中,醇类物质最为丰富,次之的酯类和羰基类物质相当。除醇类物质外,D254发酵的火龙果酒酯类物质最为丰富,其次是R2发酵的火龙果酒。综合考虑,R2酵母及采用清汁发酵较适合红芯火龙果酒的酿制。     

偶联协酵法生产红心火龙果酒工艺初探

采用多菌协联发酵等前沿加工技术,使用新鲜红心火龙果为发酵原料,通过挑选、清洗、破碎榨汁以后添加实验室自筛的火龙果酒酵母和生香酵母,采用多菌协联发酵,所得的产品口味纯正、香气突出浓郁、回味协调丰盈的火龙果酒。     

响应面法优化二次发酵红曲火龙果酒发酵工艺

红曲火龙果酒是以火龙果为原料,采用酵母一次发酵、红曲二次发酵制得发酵酒。在单因素试验基础上,应用Box-Behnken中 心组合试验设计建立一次发酵、二次发酵数学模型进行响应面分析,优化火龙果酒发酵工艺。结果表明,红曲火龙果酒一次发酵优化 条件为发酵时间5.3 d,发酵温度29.3 ℃,酵母接种量0.024%,加糖量17.4%,此条件下制得一次发酵样品感官评分为86.8分。 二次发酵 优化条件为发酵时间62 h,发酵温度30.2 ℃,红曲米添加量9.2%,此条件下制得的红曲火龙果酒成品总酯含量为15.42 g/L,感官评分 为91.1分。     

火龙果酒酿酒酵母的筛选

为筛选出适合酿造火龙果酒的菌种,分别对10种商业酿酒酵母进行发酵能力进行综合评价和筛选。结果表明:在发酵温度25℃、菌种添加量0.01%的条件下,适合红芯火龙果酒发酵的菌种为F15酵母,所得的酒体红色,香味浓郁,具有明显的火龙果香气及酒香。     

基于混菌发酵改善火龙果酒品质

为了使火龙果酒的品质得到更好地提升,该研究采用酿酒酵母、库德里阿兹威毕赤酵母和植物乳植杆菌发酵火龙果酒,分析火龙果酒发酵过程中的理化指标及风味物质。研究发现,酿酒酵母、库德里阿兹威毕赤酵母和植物乳植杆菌联合发酵（Zw组）能显著提高糖的利用率,减少甜菜红素和酚类物质的损失,生物降酸能力也很好。利用液相色谱-质谱法检测发酵样品的有机酸,结果表明,火龙果酒中主要的有机酸为乳酸和乙酸,而柠檬酸的相对含量最低。相对于其他发酵组,Zw组（10.28%）有机酸相对含量较低,说明植物乳植杆菌有良好的降酸能力。利用气相色谱-质谱法检测发酵样品的香气成分,共检测出63种香气成分,Zw组发酵样品中醇类物质的种类和浓度明显提高,果香味与花香味增强。感官评价结果表明,Zw组在色、香、味方面得分最高,酸甜适中,颜色鲜亮。因此,利用酿酒酵母、库德里阿兹威毕赤酵母和植物乳植杆菌联合发酵,有利于改善火龙果酒的口感,增加其香气复杂度,提高品质。该研究首次利用酿酒酵母、非酿酒酵母和植物乳植杆菌联合发酵火龙果酒,可为火龙果酒品质控制和技术开发提供必要的理论基础。     

火龙果酒酿酒酵母的筛选

为筛选出适合酿造火龙果酒的菌种,分别对10种商业酿酒酵母进行发酵能力进行综合评价和筛选。结果表明:在发酵温度25℃、菌种添加量0.01%的条件下,适合红芯火龙果酒发酵的菌种为F15酵母,所得的酒体红色,香味浓郁,具有明显的火龙果香气及酒香。     

响应面法优化仙人掌果-红心火龙果酒发酵工艺

该试验以仙人掌果、红心火龙果为原料制作复合果酒,并优化最佳发酵工艺条件。通过单因素和响应面试验探讨仙人掌果果肉质量与红心火龙果果肉质量比、焦亚硫酸钾添加量、发酵温度、初始糖度、酵母接种量对仙人掌果-红心火龙果酒发酵产酒精量及感官评分的影响。结果表明,仙人掌果-红心火龙果酒的最佳发酵条件为：果肉质量比1∶1,焦亚硫酸钾0.03%,发酵温度24 ℃,初始糖度22 °Bx,酵母接种量0.03%,此条件下制得仙人掌果-红心火龙果酒的酒精度11.89%vol,感官评分为95.5分。果酒清澈色泽鲜艳,酒香醇厚协调,具有典型果香。     

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.