真空油炸苹果脆片预处理工艺优化

为优化苹果脆片预处理工艺,在单因素试验的基础上,采用均匀设计法,以破碎力、含油量、L*值、感官评分、综合评分和电子鼻检测挥发性成分为指标,对数据进行多元回归分析。结果表明:破碎力经二次逐步回归分析,达到极显著(P<0.01),相关系数到达0.960,模型拟合度好;经一次逐步回归分析,感官评分、L*值和综合评分达到显著水平(P<0.05),含油量达到极显著水平(P<0.01);浸渍液配比和漂烫温度影响产品感官评分和L*值;浸渍液配比、漂烫温度、漂烫时间和冷冻时间4个因素影响产品含油量和综合评分;经偏最小二乘法回归分析,得到模型预测最佳工艺为:麦芽糖添加量14%、蔗糖添加量5%、麦芽糊精添加量15.7%,漂烫温度98℃,漂烫时间2 min,冷冻时间3 h。在此工艺条件下,样品的破碎力为53.1 N、感观评分为83.0、含油量为17.2%、L*为89.9、综合评分为89.6,且样品风味品质最佳。     

响应面-主成分分析法优化马铃薯挂面工艺

本文以小麦粉、马铃薯全粉为主要原料,豆腐柴叶为辅料,采用单因素和Box-Behnken实验设计,响应面和主成分分析法优化马铃薯挂面加工工艺。结果表明:第1~第3主成分累计贡献率达到86.10%,足以描述马铃薯挂面质构、感官、烹调损失率和干物质吸水率综合反应的挂面品质。以主成分分析得到的规范化综合评分为响应值建立的二次多项式回归模型回归效果显著,拟合度较好(p0.0001,R2=0.9699)。偏最小二乘法回归分析预测马铃薯挂面最佳综合评分工艺参数为:马铃薯全粉添加量31%,豆腐柴汁液添加量9%,醒发时间31 min,醒发温度25℃,理论综合评分值达到0.9194,该条件下马铃薯挂面规范化综合评分达0.9116,与模型预测值接近,表明以主成分分析得到的规范化综合评分为响应值建立的回归模型具有良好的预测能力。     

不同预处理对马铃薯片浸渍速率及感官品质的影响

采用理化测定和感官评定相结合的方法考察了烫漂、冷冻、微波干燥、烫漂+冷冻四种预处理方式对马铃薯片在麦芽糊精溶液中的浸渍速率及感官品质的影响。结果表明,以45%的糊精溶液为浸渍液,在45℃下进行浸渍,烫漂+冷冻的预处理方式浸渍速率最大,在30min时即已达最大浸渍量的80%,基本满足工艺要求;经此处理浸渍后的薯片外形平整饱满,色泽浅黄半透明,质感厚实。烫漂+冷冻的预处理方式可作为马铃薯脆片加工中浸渍工序的最佳预处理措施。     

添加辅料对压差闪蒸联合干燥马铃薯复合脆片品质的影响

以马铃薯和胡萝卜为主要原料,分别添加蔗糖、麦芽糖醇、大豆蛋白等不同辅料,采用压差闪蒸联合干燥工艺加工再造型马铃薯复合脆片,探究不同辅料对再造型马铃薯复合脆片品质的影响。结果表明:各类辅料对复合脆片的色泽、质构、感官评价、微观结构等品质均有显著影响,具体表现为大豆蛋白显著提高脆片的L*值、ΔE值,蔗糖、蔗糖和大豆蛋白复合辅料均显著提高脆片的脆硬度并形成了较好的孔隙结构;感官评价结果表明,分别加入蔗糖和麦芽糖醇的马铃薯复合脆片消费者偏爱度较高。采用主成分分析法提取了3个主成分,并对所得到的马铃薯复合脆片品质指标进行综合分析,结果显示加入10%~13%(m/m)麦芽糖醇的马铃薯复合脆片不仅感官品质较佳,脆硬度较好,且相比添加其他辅料维生素C含量损失较少。综合考虑,麦芽糖醇可作为辅料添加用于改善再造型马铃薯复合脆片品质。     

不同预处理方法对真空冷冻干燥香菇脆片感官品质的影响

利用漂烫超声浸渍、漂烫真空浸渍、漂烫调味液煮、熏蒸超声浸渍、纤维素酶解5种不同预处理方法处理香菇,再用真空冷冻干燥工艺将其制成即食脆片,对香菇脆片感官品质特性(包括水分含量、色泽、质构)以及微观结构等进行比较。结果表明:与其他4种预处理方法相比,经过纤维素酶解处理后的香菇制备成冻干脆片水分含量为3.59%、?E为107.35±2.16、硬度为718.20 g、脆度为0.92 mm、感官评分为8.1±0.2,其感官品质最佳,纤维素酶处理有助于香菇脆片形成疏松多孔结构。     

马铃薯面条的配方优化

为提高马铃薯的综合利用价值,以低筋面粉、马铃薯泥为主要原料,基于单因素和Box-Behnken试验设计,采用主成分分析法和响应面优化马铃薯面条配方。结果表明,马铃薯泥添加量为15%、食盐添加量3.6%、和面时间15 min时最优;在此条件下获得的马铃薯面条的综合得分值为0.774 5,与理论综合评分值0.781 7接近。由主成分分析得到的规范化综合评分为响应值建立的二次多项式回归模型效果显著,且拟合度较好(p0.001,R~2=0.951 2)。试验表明,响应面结合主成分分析法优化主成分分析法对马铃薯面条的品质的综合优化具有较好的效果。     

真空低温油炸紫香芋脆片预处理工艺优化

研究真空油炸紫香芋脆片的预处理工艺。在单因素试验基础上,对主要影响因素进行正交试验设计,系统研究了切片厚度、漂烫条件、冷冻条件等影响真空低温油炸紫香芋脆片质量的预处理因素,获得了真空低温油炸紫香芋脆片的最佳预处理工艺:切片厚度3 mm;漂烫温度90℃,漂烫时间4 min;在-30℃的冷冻环境中,冷冻18 h较为合适;在-0.094 MPa~-0.098 MPa的真空度条件下,95℃真空油炸15 min。真空油炸紫香芋脆片最大程度地保存了紫香芋的营养价值,经测定花青素含量为1.38 mg/g,脂肪质量分数为15.49%,破碎力为437.3 g。产品带有清晰的纹理,口感酥脆,无渣感,无油腻感。     

变异系数法评价预处理方式对黄秋葵热风干燥品质特性的影响

目的：改善黄秋葵干制品品质。方法：以复水比、收缩率、维生素C含量、干燥时间和感官评分为指标分析不同预处理方式对黄秋葵干制品品质的影响,并采用变异系数法对其指标进行综合加权评价。结果：烫漂和超声波预处理可显著提高干制品的复水比(P＜0.05);收缩率受烫漂的影响最大;3种预处理组的维生素C含量均低于照组,其中超声波处理组的损失最小;烫漂和超声波预处理可缩短样品的干燥时间;超声波和护色预处理样品的感官评分明显高于烫漂预处理的样品(P＜0.05)。变异系数法综合评价表明：超声预处理的黄秋葵品质最好,护色预处理次之,烫漂预处理综合评分最低;超声波预处理温度为20 ℃时所得干燥样品综合评分最高,为0.907。结论：超声波预处理在黄秋葵热风干燥中是一种较优的预处理方式。     

响应面法优化马铃薯鲜料热干面工艺

以新鲜马铃薯为原料研制非油炸方便型马铃薯鲜料热干面,可以避免马铃薯营养物质的破坏和特有风味的流失。通过研究马铃薯泥、变性淀粉及蛋清粉添加量对面条蒸煮品质、质构特性和感官评分的影响,利用响应面和主成分分析法,建立马铃薯鲜料热干面综合品质的评价方法。马铃薯鲜料热干面的最佳工艺配方为:小麦粉89.7%,马铃薯泥添加量42%,变性淀粉添加量8.5%,蛋清粉添加量1.8%。该条件下制得的面条综合品质最佳,回归模型预测的规范化综合评分达到0.924,与实际值0.931接近,表明以规范化综合评分为响应值建立的回归模型具有良好的预测能力。     

响应面法优化甘薯脆片干燥工艺

为探究甘薯脆片热泵干燥最佳工艺,在单因素试验基础上,以烘干温度、烘干时间、切片厚度、汽漂时间为影响因素,以含油率及感官评分为响应值,用Box-Behnken试验设计建立响应面分析模型。结果表明,甘薯脆片烘干最佳工艺为:烘干温度74℃、切片厚度2.7 mm、汽漂时间3 min,烘干时间为3.5 h,在此优化条件下,甘薯脆片油炸后感官评分为88.75分,含油率为7.84%,在此条件下得到的产品色香味俱全。     

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.