响应面法优化胡萝卜膳食纤维酸奶工艺北大核心CSCD

将胡萝卜水溶性膳食纤维以不同比例加入酸奶中,在单因素试验的基础上,采用响应面分析法,优化膳食纤维添加量、接种量、发酵时间及发酵温度的工艺参数。结果表明,胡萝卜水溶性膳食纤维能促进乳酸菌的生长,添加胡萝卜水溶性膳食纤维前后乳酸菌活菌数分别为2.6×10~7和4.3×10~8mL^(-1),一定范围内降低酸奶的pH值,增加酸奶的持水力和黏度,并改善酸奶的组织状态。胡萝卜膳食纤维酸奶的最佳工艺参数为胡萝卜水溶性膳食纤维添加量2.17%,乳酸菌接种量3.46%,发酵温度42.3℃,发酵时间6h。该条件下制得的酸奶,香味浓郁,质地均匀,口感爽滑细腻。     

单一干酪乳杆菌KL1发酵益生菌酸奶工艺条件的研究

应用单因素实验及正交实验,确定单一干酪乳杆菌KL1发酵酸奶的最佳原料乳,并对其益生菌酸奶发酵工艺条件进行优化。筛选得到的最佳原料乳为M_2,同时通过添加M_6改善酸奶的色泽与组织状态;采用三因素三水平L_9(3~4)正交实验优化酸奶的发酵工艺条件,接种量是影响KL1发酵酸奶品质的最主要因素,确定干酪乳杆菌KL1发酵酸奶的优化条件如下:接种量为6.0%,M_6添加量1.0%,葡萄糖添加量1.5%,37℃下发酵酸奶22 h,优化后的益生菌酸奶的活菌数量较对照组高10倍。     

响应面法优化胡萝卜膳食纤维酸奶工艺

将胡萝卜水溶性膳食纤维以不同比例加入酸奶中,在单因素试验的基础上,采用响应面分析法,优化膳食纤维添加量、接种量、发酵时间及发酵温度的工艺参数。结果表明,胡萝卜水溶性膳食纤维能促进乳酸菌的生长,添加胡萝卜水溶性膳食纤维前后乳酸菌活菌数分别为2.6×10~7和4.3×10~8mL~(-1),一定范围内降低酸奶的pH值,增加酸奶的持水力和黏度,并改善酸奶的组织状态。胡萝卜膳食纤维酸奶的最佳工艺参数为胡萝卜水溶性膳食纤维添加量2.17%,乳酸菌接种量3.46%,发酵温度42.3℃,发酵时间6h。该条件下制得的酸奶,香味浓郁,质地均匀,口感爽滑细腻。     

植物型保健酸奶的制备工艺

本文研究植物型保健酸奶。植物型车前草酸奶的优质配方为酸奶与车前草汁1∶1的比例,蔗糖的添加量为7%,发酵温度40℃,发酵时间5 h,它喝起来不仅细腻香甜可口,还可以消炎止泻利尿解毒。蒲公英酸奶的优质配方为蒲公英汁与酸奶1∶1的添加量,蔗糖添加量5%,发酵温度40℃,发酵时间5 h,既清热解毒又可以改善便秘,还具有强大的保健功能。牛蒡酸奶的优化配方为牛蒡汁与酸奶1∶1的添加量,蔗糖添加量5%,发酵温度40℃,发酵时间5 h,既可以驱热风散还可以降三高,还具有减肥功效。桑菊酸奶的优化配方是桑叶粉菊花汁的混合液与酸奶1∶1的添加量,蔗糖7%的添加量,40℃发酵5h,具有清热解毒,化痰止咳的功效,还可以维护肠道,促进消化吸收补充肠道里的有益菌营养。但是车前草、桑菊都是寒性食物,不能经常食用或者与热性食物同食。     

花生芽鹰嘴豆复合酸奶的发酵工艺优化

以奶粉、花生芽和鹰嘴豆为主要原料,安琪12菌型酸奶发酵剂为发酵菌种,制备花生芽鹰嘴豆复合酸奶。以酸度、黏度、乳酸菌数、感官评分为评价指标,研究糖添加量、接种量、发酵温度和发酵时间对花生芽鹰嘴豆复合酸奶发酵的影响,并采用正交试验优化其发酵条件。结果表明,各因素对酸奶感官评分的影响顺序依次为接种量＞糖添加量＞发酵温度＞发酵时间;各因素对乳酸菌数的影响依次为接种量、发酵时间、发酵温度、糖添加量。花生芽鹰嘴豆复合酸奶最佳发酵工艺条件为接种量5 g/L,白砂糖添加量8%,发酵温度39 ℃,发酵时间24 h。此优化条件下获得的酸奶风味良好,乳酸菌数为8.11×108 CFU/mL,感官评分为92分,酸度为78.31 °T。     

响应面法优化百香果酸奶的发酵工艺

通过单因素试验、Plackett-Burman实验、最陡爬坡试验和响应面优化法确定百香果酸奶最佳发酵工艺。结果表明:以果汁添加量、白糖添加量和发酵温度为自变量,响应面法优化出百香果酸奶的最佳发酵工艺为白糖添加量7.4%,接种量0.1%,百香果果汁添加量5.5%,发酵温度42.7℃,发酵时间5 h。在此条件下,酸奶感官评分约达到94.33分,与预测值(93.97分)相差较小。百香果酸奶的酸度、乳酸菌数和大肠杆菌数检测结果均符合食品安全国家标准。     

胡萝卜风味酸奶粉的制备及其速溶特性研究

以保加利亚乳杆菌(Lactobacillus bulgaricus)和嗜热链球菌(Streptococcus Thermophilus)混合菌种发酵胡萝卜汁和牛奶的混合物制作酸奶,通过正交实验方法优化胡萝卜风味酸奶的最佳发酵工艺,而后采用低温冷冻干燥制得酸奶粉对其速溶特性进行研究。结果表明,胡萝卜风味酸奶的最佳配方为:接种量0.15%,蔗糖添加量7%,胡萝卜汁添加量15%(均为质量分数),发酵温度为42℃,发酵时间为6 h。速溶特性研究表明,在发酵后添加10%的麦芽糊精进行冷冻干燥得到酸奶粉,润湿下沉时间更短,说明其具备良好的速溶特性。此外,在冷冻前添加冷冻保护剂有助于改善胡萝卜风味酸奶粉的冲调性以及提高活菌数。     

芦荟紫山药复合醋生产工艺优化

研究芦荟紫山药复合醋的酿造工艺条件,利用响应面分析实验并得到最佳工艺条件。实验结果表明:芦荟紫山药复合醋的最佳酿造条件为:酒精发酵阶段,发酵液糖度为17.2%,酵母菌接种量为0.3%,发酵温度为25℃,发酵时间为120 h;醋酸发酵阶段,发酵酒液酒精度为8.4%,醋酸菌接种量为13.1%,发酵温度为33℃,发酵时间为144 h。     

抹茶益生菌有机酸奶的研发及贮存期品质分析

以有机生牛乳和有机白砂糖为主要原料,添加抹茶粉和益生元等配料共同进行发酵,研发抹茶益生菌有机酸奶产品,并对其贮存期品质进行分析。通过单因素试验和正交试验分别考察抹茶粉添加量、菊粉添加量、发酵剂接种量和发酵时间对抹茶益生菌有机酸奶感官品质的影响。结果表明,抹茶益生菌有机酸奶的最优发酵工艺为白砂糖添加量8%、发酵温度42 ℃、发酵时间6 h、抹茶粉添加量0.09%、菊粉添加量1.5%、发酵剂接种量0.01%。在此优化条件下,抹茶益生菌有机酸奶感官评分为97分,酸度为78 °T,产品色泽明亮呈淡绿色、口感细滑、风味浓郁。     

香蕉抗性淀粉保健酸奶的研制

研究以香蕉抗性淀粉为功能因子的搅拌型保健酸奶的加工工艺。考察香蕉粉添加量对产品品质的影响,以及贮藏过程中酸奶品质的变化。结果表明：香蕉粉最佳添加量3%;香蕉香精最佳加入量0.05‰;优化所得的酸奶发酵工艺参数组合为发酵温度40℃、接种量4%、发酵时间4.0h;在4℃条件下可以贮藏7d。所研制的香蕉抗性淀粉保健酸奶,营养价值丰富、抗性淀粉保留率高,为开发优良物性和高膳食纤维的保健型酸奶提供理论依据。     

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.