响应面分析法优化草鱼的干腌工艺

优化了草鱼干腌工艺条件,为腊鱼生产提供理论依据.以腌制后鱼肉盐溶性蛋白含量、氯化钠含量、盐卤蛋白质含量为指标,通过单因素实验及响应面分析法,研究不同腌制条件(时间、温度、加盐量)对终产品-腊鱼品质的影响,并建立感官评定结果与测定指标的数学模型,以优化干腌工艺条件.结果表明,鱼肉中氯化钠的含量及盐卤中蛋白质含量与腌制时间、温度和加盐量呈正相关;腌制时间、温度对鱼肉盐溶性蛋白含量有一定影响.采用响应面分析法建立感官评定与腌制条件的数学模型,曲面回归方程拟合性好.对感官评定结果的影响:加盐量＞腌制温度＞腌制时间.其中,腌制时间和腌制温度对腊鱼感官评定结果的影响显著.通过响应面交互作用分析与优化,最佳腌制条件:腌制温度为9.3℃,腌制时间6d,加盐量11.70％,所得腊鱼的感官评分值与模型预测值基本相符.     

响应面分析法优化海鳗的湿腌工艺

目的:优化鳗鱼肉湿腌工艺条件,为鳗鲞生产提供理论依据。方法:以腌制后鱼肉盐溶性蛋白含量、氯化钠含量、盐卤中蛋白质含量为指标,通过单因素试验及响应面分析法,研究不同腌制条件(时间、温度、盐度)对鳗鱼肉品质的影响,并建立感官评定结果与测定指标间的数学模型,以优化湿腌工艺条件。结果表明:1)鱼肉氯化钠含量及盐卤中蛋白质含量与腌制时间、温度和盐水浓度呈正相关;腌制时间、温度对鱼肉盐溶性蛋白含量有一定影响。2)采用响应面分析法建立感官评定与腌制条件的数学模型,曲面回归方程拟合性好。对感官评定结果的影响:盐水浓度极显著,腌制时间较显著,而腌制温度不显著。3)通过响应面交互作用分析与优化,最佳腌制条件:腌制时间0.91h、温度9℃、盐度13.50%,所得鳗鲞的感官评分值与模型预测值基本相符。结论:腌制时盐水浓度对鳗鲞感官评定结果的影响极显著,鳗鱼肉湿腌的最适盐度为13.50%。     

响应面分析水酶法提取茶叶籽油工艺优化研究

茶叶籽作为茶叶生产副产物,富含油脂及茶皂素等成分.试验采用中性蛋白酶进行水酶法提取茶叶籽油工艺研究,单因素试验探索酶量、作用温度、作用时间、料液比等对油得率影响,并对副产物茶皂素得率进行测定;在此基础上开展中心组合试验,进行响应面分析对油脂提取工艺进行优化.研究结果表明回归方程为:Y=-65.950+3.011X1+1.522X2+10.167X3+5.685X4+0.167X1X3-0.108X1X4+0.0433X2X4-0.300X3X4-0.166X12-0.0157X22-1.059X32-0.797X42,最佳提取条件为酶量10.83 mL、酶解温度53℃、料液比1∶5.19、酶解时间3.30 h,验证试验油得率为26.053％,为茶叶籽资源开发提供了理论指导.     

酸浸草鱼腌制工艺研究

目的：改善腌鱼的口感，缩短腌制时间，减低盐含量，提高腌制品安全性；方法：以草鱼为原料，通过感官评定，比较几种不同酸（食醋、柠檬酸、乳酸）的处理效果；并以细菌总数，挥发性盐基氮为主要指标，研究腌制液浓度、液固比（W：V）、腌制时间、加酸量等对产品品质的影响；结果：食醋的处理效果优于其它2种酸；液固比为2：1、腌制时间2h、腌制液浓度10％、食醋添加量3％时，产品具有良好口感，盐含量为8％，细菌总数少于20000CFU／g，TBVN指数小于60mg／100g.符合低盐安全的要求。     

高盐大头菜脱盐因素的研究

传统腌制大头菜一般采用高盐腌制,制成的大头菜盐含量在15%～20%,口感太咸,不利于身体健康,使其生产和销售都在一定程度上受到了限制。该试验以含盐量和感官评分为评价指标,研究了料液比、脱盐时间、脱盐温度、换水次数4个因素对高盐大头菜脱盐效果的影响,最终得出最佳脱盐工艺条件为料液比1∶3（g∶mL）,脱盐温度20 ℃,脱盐时间15 min、换水次数2次。在此条件下,脱盐后大头菜含盐量为4.12%,且感官评定效果最佳。 关键词：中图分类号：TS255.3 文章编号：0254-5071（20１6）07-0135-04 doi：     

二次回归正交旋转组合设计优化苏麻饼粕中植酸的提取工艺

在单因素实验的基础上,采用二次回归正交旋转组合设计,研究了饼粕粒径(X1)、盐酸浓度(X2)、浸提时间(X3)、浸提温度(X4)及料液比(X5)5个因素对苏麻饼粕中总植酸得率的影响,并用DPS7.05分析软件建立了5个因素与植酸得率之间的回归模型:Y=2.48748+0.11968X1+0.11318X2+0.00821X3+0.04922X4+0.05354X5+0.05193X12-0.02435X22+0.01836X32-0.00272X42-0.00605X52,得出了各因素对植酸总得率的影响顺序为:饼粕粒径>盐酸浓度>料液比>浸提温度>浸提时间。从模型可知,当饼粕粒径为120目、盐酸浓度0.63mol/L、浸提时间20min、浸提温度51℃、料液比1∶8条件下的植酸得率最高,可达3.13%,验证实验结果与理论值基本一致。     

两种方法提取桦褐孔菌多糖工艺研究

对桦褐孔菌进行多糖提取,利用热水浸提和微波浸提进行比较,使用响应面分析法对其数据进行分析.试验结果表明,微波浸提优于热水浸提,微波浸提时各项影响程度:功率(X1)＞水料比(X2)＞时间(X2),其最佳工艺条件为:功率720 W、提取时间32 min、液料比1:80(V:W).在该条件下的响应面模型预测的多糖含量为22.66%.比热水浸提比较时间缩短了3.2倍,桦褐孔菌多糖得率在最优工艺平行比较中提高了21.72%.     

响应曲面法化儿茶素的浸提条件

以信阳毛尖茶叶沫为原料,优化儿茶素的浸提务件,考察乙醇浓度、时间、温度和液料比对浸提儿茶素的影响.采用响应曲面法建立回归模型为:Y=0.500429-0.047625X1 0.021625X3-0.012054X21 0.03775X1X3-0.0325X2X3,优化得到最佳浸提条件为:乙醇浓度70%、浸提时间20min、浸提温度80℃和液料比15:1(mL:g).     

酶法提取白酒糟中酚酸物质工艺

采用二次回归正交旋转组合设计对酶法提取白酒糟中酚酸类物质的工艺进行研究。考察了加酶量(X1)、反应时间(X2)、pH值(X3)和液料比(X4)4个试验因素对总酚酸产率(Y)的影响,并得到回归模型:Y=1.28321+0.04783X1+0.03728X2+0.12048X3+0.05152X4-0.05027X12+0.01514X22+0.00099X32-0.03790X42+0.02000X1X2+0.03000X1X3+0.00250X1X4。其最佳工艺条件为:加酶量10mL/100g、酶解时间150min、pH6.6、液料比25:1,得到的最高总酚酸产率为1.51%。实测值与模型预测值偏差为0.67%。高效液相色谱分析表明酶解前后反式阿魏酸含量变化极其显著。     

响应面优化柠檬蜡伞多酚类物质的提取工艺研究

柠檬蜡伞(Hygrophorus lucorum Kalchbr.),又称小黄蘑,是一种外生菌根食用真菌.以柠檬蜡伞为试验材料,对柠檬蜡伞多酚的水浴提取工艺进行了研究.在单因素实验的基础上,采用Box - Behnken设计和响应面分析法对影响提取效果的4个主要因素即提取温度(X1)、提取时间(X2)、乙醇浓度(X3)和液料比(X4)进行了优化,建立了各因子与多酚得率之间关系的数学模型为:Y=12.32 +0.54X1 +0.31X2+0.088X3 +0.28X4 -0.10X1X2 -0.33X1X3 -0.047X1X4 -0.21X2X3 -0.25X2X4 +0.15X3X4 -0.92X12 -0.24X22- 1.07X32 -0.29X42.根据上述回归模型通过Design Expert 7.1.0软件分析得出多酚的最佳提取工艺条件为:提取温度53℃,提取时间45 min,乙醇浓度60％,液料比36 mL/g,提取2次;在此条件下,柠檬蜡伞多酚的得率可达12.46+0.07 mg/g (n=3);与模型预测值(12.50mg/g)相比,差异不显著(P＞0.05).试验结果可为柠檬蜡伞多酚类成分的进一步研究提供科学依据.     

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.