质构改良剂对谷物早餐保脆性的影响

本文研究了不同乳化剂和胶体对谷物早餐脆性、保脆性及硬度的影响,并进一步探讨羧甲基纤维素钠(CMC)对谷物早餐保脆性的影响机理。将小米、玉米、大麦和小麦按照55%︰25%︰10%︰10%的比例混合,并分别添加一定量的5种胶体(果胶、海藻酸钠、黄原胶、明胶、羧甲基纤维素钠)或4种乳化剂(蔗糖脂肪酸酯、硬脂酰乳酸钠、大豆软磷脂、分子蒸馏甘油单脂肪酸酯),用双螺杆挤压机制备谷物早餐。试验结果表明,乳化剂不能改善谷物早餐的质构,而胶体中的羧甲基纤维素钠(CMC)能有效提高谷物早餐的脆性和保脆性。其最适宜的添加量为3‰。X-射线衍射结果表明,CMC的添加使淀粉在挤压过程中部分淀粉晶型免受破坏,淀粉结晶度提高。扫描电镜观测发现CMC可使谷物早餐内部结构更加致密,孔洞减少。     

谷物组成对挤压膨化产品品质的影响

该实验以6种谷物(粳米、小麦、玉米、糯米、小米、燕麦)为原料,考察不同谷物原料组成成分与产品膨化特性之间的相关性。结果表明,挤压后谷物膨化制品的一些指标得到很大提高,如吸水性指数、水溶性指数;蛋白质含量及脂肪含量与膨胀度呈负相关,淀粉含量与膨胀度呈正相关,膨化制品中蛋白质及脂肪含量要控制在合理范围内;水溶性指数与蛋白质含量呈极显著正相关,与总淀粉含量呈极显著负相关;糊化度与总淀粉含量呈极显著正相关,与蛋白质、粗脂肪含量呈极显著负相关。粳米、小麦以及糯米的膨化特性要优于玉米、小米以及燕麦,其中糯米在膨胀度、体积密度、水溶性指数、糊化度、硬度以及脆度方面都表现较为优异,膨化性能最好。综上所述,6种谷物原料中,糯米、小麦和粳米的挤压特性较好,可作为挤压膨化的主要原料,玉米、小米以及燕麦可根据成本适量添加。     

挤压谷物原料成分与理化性质之间的相关性分析

采用双螺杆挤压机将9种谷物在同一条件下挤压膨化,研究比较了9种谷物原料挤压后的理化性质:糊化度、吸水指数、水溶性指数、膨胀度、硬度、脆性和保脆性,分析了谷物原料成分与挤压后产品的理化性质之间的相关关系,以及各理化性质之间的相关关系。     

小麦、糯米、红薯、玉米加工饴糖的工艺

用小麦或大麦与糯米、红薯、玉米、小米为原料,经过加工,可制成色泽黄、性状粘糊、味道甘甜     

酿酒原料对白酒风味的影响

采用5株酿酒酵母在酿酒原料(高粱、大米、小米、小麦、玉米)上进行发酵培养,分析其代谢产物.结果证明,小麦是良好的制曲原料;高粱产酒香,大米产酒净,小米是芝麻香型酒酿造的重要原料;证实了“小麦制曲,高粱酿酒”的科学合理性.     

谷物复合挤压膨化工艺参数对膨化特性的影响研究

以小米、大麦和豆粕为原料(8:1:1),以德国进口的DSE-25型双螺杆挤压膨化实验室工作站为膨化设备,对影响挤压膨化特性(膨化度、糊化度)的各个工艺参数(原料水分含量、加工温度、螺杆转速、喂料速度)进行系统研究,研究各因素对挤压膨化特性的影响规律。     

宠物狗咬胶配方及工艺的优化

通过对挤压产品进行质构测试,考察弯曲应力、杨氏弹性模量及弯曲应变参数,在单因素实验的基础上,优化了以玉米淀粉为主要原料的狗咬胶的配方,以干物质为100％计算,各配料占干物质的比例为玉米淀粉89％、玉米粉10％、复配胶体(黄原胶∶塔拉胶=1∶1)1％、甘油15％、加水量30％、乌龙茶2％.在优化后的配方下对挤压参数进一步优化,使产品在适当的弯曲应力下,降低杨氏弹性模量,增加弯曲应变,以得到具有较高硬度且韧性上佳、不易断裂的产品. 最终确定挤压参数为60-70-85-95℃,挤压转速为140r/min,喂料速度为50r/min.     

应用均匀设计和响应面分析优化谷物早餐的挤压工艺

以小麦、燕麦和玉米粉为主要原料，以脆性和保脆性为主要指标，通过均匀设计得到挤压工艺中对品质影响较大的3个因素及其取值范围。再通过响应面分析对谷物早餐的挤压工艺进行优化，得出最佳的挤压工艺为：螺杆螺旋速度为334r／min；Ⅰ区温度为40℃；Ⅱ区温度为150℃；Ⅲ区温度为123．50℃；水分质量分数22．60％；蛋白质质量分数7．3％；脂肪质量分数8％。     

大麦饮料制备工艺的研究

分别对3种经过不同处理的大麦做出的饮料进行研究,得出挤压是最适合的预处理方法.另对制作大麦饮料过程中的挤压工艺和酶解工艺进行初步研究.挤压工艺中,采用挤压末端温度140℃,物料水分22％,进料速度0.8(进料螺杆转速18 r/min),挤压螺杆转速100 r/min的条件,可使原料最大程度的糊化.酶解工艺中,在淀粉酶用量30 U/g,酶解时间60 min,酶解温度60℃,料液比1∶10的条件下,可制作出最佳的大麦饮料.     

小米—小麦预混合粉的粉质特性和糊化特性研究

研究了小米粉与小麦粉混合所得混合粉的粉质特性和糊化特性.结果表明:随着小米粉添加量的增加,小米—小麦预混合粉面团形成时间先上升后降低,面团稳定时间、粉质指数、峰值黏度、最低黏度、衰减值、最终黏度、回生值、峰值时间均呈下降趋势,弱化度和公差指数均呈上升趋势;5∶1、4∶1、3∶1和2∶1未挤/挤压小米—小麦预混合粉的吸水率均呈先上升后降低再上升的趋势,1∶1未挤/挤压小米—小麦预混合粉的吸水率呈先降低后上升的趋势.制作含量较高的小米馒头和面条时,可选用2∶1或1∶1未挤/挤压小米粉.     

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.