焙炒对米茶中丙烯酰胺和晚期糖基化终产物的影响

研究焙炒温度、时间、加水量和浸润时间对米茶加工过程中丙烯酰胺(Acrylamide,AA)和晚期糖基化终产物(Advanced glycation end products,AGEs)的影响。结果表明,随着焙炒温度升高和时间的增加,AA和AGEs含量增加,但是当温度高于200℃时AA含量会呈现降低趋势;随加水量增加和浸润时间延长,AGEs含量显著性减少(p0.05),米茶中的AA含量先降低,在加水量超过10%,浸润时间超过10 min之后升高。在190℃,加水量10%(w/w),浸润10 min,焙炒35 min最适加工条件下AA和AGEs含量分别为141μg/kg和360 AU/g,低于同类产品,正常食用对人体安全。     

米茶的焙炒工艺研究

以碎米为原料,经浸润焙炒等工序制得米茶,研究米茶焙炒工艺对米茶茶汤感官品质的影响。结果表明,米茶茶汤的色彩是在焙炒过程中形成的,茶汤以黄色为主,略带绿色,透明度较高。较长的焙炒时间和较低的加水量有利于增强茶汤黄绿色和色彩纯度,使感官品质增加。米茶茶汤的色泽、滋味、香气与红度呈显著的负相关,与黄度、彩度呈显著的正相关。适宜的工艺为,按碎米质量的5%加水浸润5 min,于150℃下焙炒40 min,用该工艺制作的米茶的汤汁清亮,具有浓郁的稻米焦香风味。     

微波处理对燕麦片品质的影响

本文研究了微波灭酶工艺与蒸煮灭酶工艺对燕麦片品质的影响,探讨了完全灭酶基础上微波时间对燕麦片营养品质、消化特性及糊化特性的影响。研究表明,与蒸煮30 min灭酶燕麦片相比,微波40 s灭酶燕麦片中粗蛋白含量、粗脂肪含量、β-葡聚糖含量和糊化温度均无显著性差异(P0.05),总酚含量显著增加了0.43 mg/g(P0.05),总淀粉含量显著增加了1.66%(P0.05),快消化淀粉含量显著增加了9.17%(P0.05),峰值黏度显著降低了14.0 cm·g(P0.05),回生值显著增加了11.9 cm·g(P0.05)。随着微波灭酶时间增加,微波燕麦片β-葡聚糖含量、总酚含量和蛋白质体外消化率均降低,粗脂肪和快消化淀粉含量增加;总酚含量及快消化淀粉含量随着微波时间增加呈显著变化,峰值黏度、最终黏度、破损值、回生值均随微波时间增加显著提高(P0.05)。微波灭酶时间对燕麦片品质的影响明显。     

米茶焙炒挥发性气味的形成与特征研究

以籼米为原料,经浸润、焙炒等工序制得米茶。采用电子鼻、顶空固相微萃取(HS-SPME)和气相色谱-质谱联用技术(GC-MS),研究焙炒过程中米茶挥发性成分的形成,为揭示谷物饮料的香气形成提供理论参考。大米的挥发性气味物质主要是己醛、壬醛等醛类,右旋萜二烯、酯类及烷烃类,随着焙炒时间的延长,挥发性物质种类和浓度逐渐丰富,米茶挥发性物质组成以醛、烷烃和杂环类为主,兼有较大比例醇、酯和酮类。焙炒米茶的香气成分主要是2-戊基呋喃、2-戊基吡啶和3-乙基-2,5-二甲基吡嗪等杂环物质。建立的基于电子鼻传感器的米茶香气成分预测模型具有很高的拟合精度。     

传统米茶和功能米茶成分分析的研究

研究分析了传统米茶和功能米茶的主要成分.结果表明,原料大米制成米茶后,碳水化合物和蛋白质的含量明显减少,粗纤维和谷物不溶性膳食纤维含量明显增加.糙米发芽后制成的功能米茶富含γ-氨基丁酸,而在传统米茶中未检出γ-氨基丁酸.     

蒸煮和焙炒整米苦荞茶香气成分分析及生产过程中主要化学成分的去向

为探索焙炒、蒸煮与重组造粒加工工艺对苦荞茶香气和营养成分的影响,跟踪检测3种工艺中各组分主要营养成分的流向分布,并采用固相微萃取结合气质联用技术对苦荞茶产品的挥发性香气成分进行对比分析。结果表明,不同工艺所得产物的营养功效成分存在显著性差异(P<0.05)。按蒸煮米工艺生产苦荞茶,蛋白质主要集中分布在黄粉中,含量为27.51g/100g;还原性糖含量从原料的0.69%降为产品的0.28%;功能性成分总黄酮主要分布在抛光粉和黄粉中,含量分别为4.98%和4.63%;由于总黄酮的流向分布使得苦荞茶成品的含量降为1.38%,按焙炒、造粒工艺生产苦荞茶,其中焙炒荞粒总黄酮仅为1.29%,用富含黄酮(4.56%)的苦荞皮粉重组的含茶荞粒,其总黄酮含量高达6.87%,两者混合后成品品质与风味显著优于按蒸煮米工艺生产的苦荞茶。从挥发性香气物质看,蒸煮米工艺苦荞茶以烷烃和烯类为主,而焙炒工艺苦荞茶则以醛类和烷烃为主,且还富含苯酚、醇类、醚类、酮类和酯类,这是焙炒苦荞茶风味优于蒸煮米苦荞茶的原因。     

发芽糙米焙炒过程中品质变化研究

为研究焙炒过程中发芽糙米品质的变化,将发芽糙米分别进行轻度、中度和强度焙炒,测定其主要成分、色泽和挥发性风味物质的变化。结果表明：3 种焙炒程度的发芽糙米中的还原糖、可溶性蛋白含量均显著低于未焙炒（P＜0.05）但三者之间差异不显著（P＞0.05）,γ-氨基丁酸（γ-aminobutyric acid,GABA）含量随焙炒程度增加而显著降低（P＜0.05）,强度焙炒的发芽糙米总酚显著高于其他两种焙炒（P＜0.05）。焙炒后直链淀粉和抗性淀粉含量均增加但3 种焙炒程度差异不显著（P＞0.05）。焙炒对总淀粉含量的变化影响不明显。a*、b*和ΔE值随焙炒程度增强逐渐增加,而L*值逐渐降低。采用顶空固相微萃取和气相色谱-质谱联用对未焙炒及不同焙炒程度发芽糙米风味物质进行提取、鉴定与分析,发现吡嗪和呋喃类物质种类和含量均显著增加（P＜0.05）。发芽糙米轻度焙炒GABA含量损失最少,且对焙烤香气起主要贡献的吡嗪类物质含量最高,达到焙炒增香目的,因此轻度焙炒较为适宜发芽糙米焙炒加工。     

稻米淀粉的酶法研制

研究了用食品级碱性蛋白酶水解米粉蛋白质制备米淀粉的工艺条件,重点考察了酶用量、pH值、反应温度和水解时间对籼米粉蛋白质水解率的影响。实验结果表明,在反应温度为55℃,pH8.5,酶用量为12.0×10-3AU/g(米粉)下水解8h,籼米粉蛋白质的水解率达到94.00%以上,米淀粉蛋白质残留量<0.5%,米淀粉收率和回收率分别高于72.00%和90.00%。     

焙炒条件对芝麻油品质的影响

本文以白芝麻为原料,研究了焙炒温度和焙炒时间对芝麻油品质的影响。结果表明：随焙炒温度提高和焙炒时间延长,芝麻油色泽加深、过氧化值升高,而酸值有所降低;芝麻油中生育酚和芝麻素含量降低,芝麻酚含量略有增高,芝麻油的氧化稳定性提高;芝麻油香味增强。可见芝麻香油生产过程中的高温焙炒对芝麻油香味和氧化稳定性有非常重要的作用。但为了减轻芝麻香油的色泽和过氧化值,最好控制其焙炒条件不超过150℃和20～30min。即使要生产香味更浓的芝麻油,其焙炒条件也不要超过200℃和30min。     

挤压和酶解挤压对豌豆粉淀粉体外消化率、蛋白质结构和流变特性的影响

目的：研究挤压和酶解挤压处理对豌豆粉理化性质的影响。方法：采用挤压和酶解挤压的方法改性豌豆粉,利用扫描电子显微镜、X射线衍射仪、傅里叶变换红外光谱、快速黏度分析仪、流变仪分析原料、挤出物和酶解物3?种样品的结构变化,并测定体外淀粉消化特性。结果：挤压处理能部分破坏豌豆的结构,表现为相对结晶度下降,I1?045?cm－1/I1?022?cm－1比值降低,黏度下降,崩解值和回生值降低;与挤压豌豆粉相比,挤压酶解豌豆粉淀粉的相对结晶度升高,黏度降低,抗剪切力和抗回生性增强。挤压和酶解挤压处理对蛋白质二级结构有明显影响,具体表现为豌豆淀粉α-螺旋相对含量减少（挤压处理）甚至消失（酶解挤压处理）,β-折叠相对含量降低,β-转角相对含量升高,无规卷曲相对含量升高。除此之外,挤压和酶解挤压处理显著提高了慢消化淀粉含量,降低了抗性淀粉含量,酶解挤压处理还可以提高豌豆粉的黏弹性和对温度的稳定性。结论：挤出物和酶解物可作为高慢消化淀粉食品的优质原料,并且因其蛋白质消化率提高和含有高赖氨酸可作为与谷类食品复配的良好原料。     

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.