亲水性胶体对玉米乳稳定性的影响

研究了多种典型亲水性食品胶体对玉米乳稳定性的影响.结果表明,亲水性胶体对玉米乳稳定性的影响与其质量浓度和种类有关.在较低的质量浓度下(2 g/L),亲水性胶体可以减少脂肪析出、降低离心沉淀率、改善流变性,显著提高感官品质.在2～8g/L的质量浓度范围内,使用卡拉胶和CMC-Na可以获得理想的稳定性.     

营养因素对乳酸乳球菌DL-203生长及其Nisin生物合成的影响

对Nisin高产菌株乳酸乳球菌DL—203的营养要求及其 对Nisin生物合成的影响进行了研究。结果表明,乳链菌 肽的生物合成与DL-203的生长呈极显著正相关,乳酸 乳球菌DL—203生长和合成Nisin的最佳碳源和氮源分 别为蔗糖和大豆蛋白胨,其适宜浓度均为15～20g/L。磷 酸盐对乳酸乳球菌DL—203生长及其Nisin生物合成具 有极大的促进作用,其中以Na_2HPO_4效果最好,其浓度 在224mmol/L以下时对菌体生长和Nisin生物合成具有 较大的促进作用。     

罗伊氏乳杆菌培养基优化及其生长代谢研究

罗伊氏乳杆菌的MRS 培养基是富培养基,简化培养基组分,优化培养基组成和培养条件是微生物工业化培养的重要基础。本实验在传统MRS 培养基基础上,首先对氮源进行单因素优化,然后采用Plackett-Burman 和中心组合试验设计对影响罗伊氏乳杆菌CG001 生长的MRS 培养基和培养条件进行筛选优化,并在最优条件下研究该菌的生长代谢情况。结果表明：酵母膏质量浓度、葡萄糖质量浓度、硫酸锰质量浓度和温度是影响菌体质量浓度的4 个关键因素;经响应面法分析确定该菌的最优培养条件为：酵母膏质量浓度20g/L,葡萄糖质量浓度20g/L,醋酸钠质量浓度7g/L,柠檬酸铵质量浓度1g/L,磷酸氢二钾质量浓度3g/L,硫酸镁质量浓度0.2g/L,硫酸锰质量浓度为0.23g/L,吐温-80 质量浓度1g/L,初始pH6.2,培养温度38.6℃,最终菌体质量浓度达0.984g/L,相对优化前提高1.102 倍。发酵罐中菌体生长曲线呈S 型,4～12h 菌体处于对数生长期,之后趋于平衡,葡萄糖的代谢与菌体的生长速率相对应。     

植物乳杆菌B002冻干工艺的条件优化

以植物乳杆菌B002为目标,研究了该菌株在冻干过程中菌泥和保护剂平衡时间、预冷冻时间和冻干保护剂对菌粉存活率的影响。结果表明,在以质量浓度100 g/L脱脂乳为基础保护剂的条件下,4℃,6 000 r/min离心15 min,菌泥和保护剂在室温下平衡40 min,厚度5 mm,-45℃预冷冻2 h,复合保护剂为质量浓度100 g/L的脱脂乳、80 g/L麦芽糊精、30 g/L谷氨酸钠和100 g/L海藻糖,在上述条件下真空冷冻干燥24 h,植物乳杆菌B002冻干存活率达到75.9%。     

Lactobacillus helveticus 9制备酪蛋白源活性肽工艺的研究

基于酪蛋白水解度和多肽质量浓度数据,研究了接种量、培养时间、培养温度及底物浓度对瑞士乳杆茵茵株L.helveticus 9水解酪蛋白的影响.结果表明.L.helveticus 9对酪蛋白的水解作用的最佳条件为接种量为1×108 mL-1,底物质量浓度为50g/L,培养时间为48 h,培养温度为37℃;在此优化条件下,酪蛋白的水解度可迭17.3%,多肽质量浓度达到0.62 g/L.显然,具有较高蛋白水解活力的菌株L.helveticus 9可以用于从酪蛋白中来制备潜在的生物活性肽.     

LF抗菌作用和CPPs促钙吸收功能及其影响因素

乳铁蛋白(LF)和酪蛋白磷酸肽(CPPs)均为天然功能性营养成分,具有抑菌、抗氧化、增强免疫力及促进钙、铁、锌等矿物质吸收等多种生物学功能.对乳铁蛋白的抗大肠杆菌性能和酪蛋白磷酸肽延缓磷酸钙沉淀效果及木糖醇、Vc等成分对其功能影响进行研究.结果显示,LF浓度在2.0 g/L时抑菌效果较强;CPPs浓度大于0.2 g/L时有较好的延缓磷酸钙沉淀效果;Vc浓度0.8 g/L,木糖醇浓度20.0 g/L时,对乳铁蛋白抑菌效果及CPPs促钙吸收均有促进作用.     

人常乳与牛常乳中全谱游离氨基酸和水解氨基酸的对比

以产后30～40 d的人常乳和牛常乳为原料,采用同位素标记相对和绝对定量结合高效液相色谱-串联质谱技术对人常乳和牛常乳中全谱游离氨基酸和水解氨基酸的种类及含量进行对比分析。结果表明,人常乳和牛常乳中游离氨基酸质量浓度分别为0.37 g/L和0.16 g/L,水解氨基酸质量浓度分别为2.5 g/L和3.3 g/L。在全谱游离氨基酸中,人常乳和牛常乳均检测到9 种必需氨基酸以及15 种非蛋白质编码氨基酸,分别检测到11 种和7 种非必需氨基酸,其中人常乳9 种必需氨基酸、10 种非必需氨基酸以及7 种非蛋白质编码氨基酸质量浓度显著高于牛常乳（P＜0.05）;在全谱水解氨基酸中,人常乳和牛常乳均检测到8 种必需氨基酸、10 种非必需氨基酸以及12 种非蛋白质编码氨基酸,其中人常乳γ-氨基丁酸、牛磺酸、α-氨基正丁酸和β-丙氨酸质量浓度显著高于牛常乳（P＜0.05）。本研究对比分析人常乳与牛常乳中全谱游离氨基酸和水解氨基酸的种类和含量差异,为配方乳制品以及功能性食品的发展提供一定的参考。     

罗伊氏乳杆菌J1胃肠道耐受性评价及其对免疫相关基因调控的体外研究

以分离自传统发酵乳制品中的罗伊氏乳杆菌(Lactobacillus reuteri,L.reuteri)J1为研究对象,对其黏附性能、生长特性、对胃肠道环境的耐受能力以及该菌株作用于Caco-2细胞不同时间后免疫相关基因表达量的动态变化进行评价。结果显示,罗伊氏乳杆菌J1具有良好的黏附性,黏附率达87.93%,具有定植于肠道中的潜力。该菌株在4 h进入对数期,14 h进入稳定期。在肠道耐受性评价中,菌株在pH为2.0和3.0条件下处理3 h后,其存活率分别为86.77%、97.12%;在胆盐质量浓度分别为0.3、0.5和1.0 g/100 mL的培养基中处理4 h后,其存活率分别为105.00%、82.60%和82.18%;经模拟人工胃液处理3 h后转入人工肠液继续培养8 h,存活率达82.71%;该菌株在7 g/100 mL的盐溶液中处理24 h后,其存活率为80.36%。此外,108CFU/mL的罗伊氏乳杆菌J1可刺激Caco-2细胞中免疫相关因子IL-1β的表达,抑制促炎因子IL-6和趋化因子IL-8的表达。综上表明,罗伊氏乳杆菌J1具有定植于肠道上皮细胞的潜力,耐受胃肠道环境,并发挥一定的免疫调节作用。     

植物乳杆菌生物合成苯乳酸条件优化研究

以苯丙酮酸为底物,以植物乳杆菌静息细胞为催化剂,对苯乳酸生物合成条件进行了优化。 试验首先确定了不同因素对苯 乳酸产量的影响,然后通过正交试验优化了最佳合成条件。 结果表明,细胞培养时间为18 h时催化活性最高,且在温度为35 ℃,pH 为6.5,静息细胞、苯丙酮酸和葡萄糖质量浓度分别为80 g/L、3.0 g/L和4.0 g/L的催化条件下,经过4 h转化,苯乳酸产量达到最高,为 1.68 g/L。 在最优条件下,静息细胞重复利用4次,苯乳酸产量没有显著降低,表现出了植物乳杆菌转化苯丙酮酸合成苯乳酸的良好稳 定性。     

基于响应面法优化凝胶过滤在分离乳铁蛋白中的工艺研究

目前我国乳铁蛋白主要依靠进口，产业化发展相对较慢，相对于其他原料，牛初乳具有廉价、易获得等优点。为低成本获得更多乳铁蛋白，本文对凝胶过滤层析纯化方法进行了优化，并设计了响应曲面试验。研究了磷酸盐缓冲液pH、流速、洗脱液浓度三个不同因素对乳铁蛋白含量的影响，通过设计三因素三水平的响应面试验分析优化凝胶过滤层析在乳铁蛋白纯化中的应用，检测方法采用紫外分光光度法，测量所得样品在475 nm处的OD值，计算出相应的质量浓度，得到最终结果。试验表明：最优工艺条件为磷酸盐缓冲液pH 7.48，流速0.20 mL/min，洗脱液浓度0.42 mol/L，预测乳铁蛋白质量浓度为170.567μg/mL。在此条件下进行三次重复试验并取平均值，实际所得乳铁蛋白质量浓度为166.485μg/mL，相对误差为2.393%，与模型基本吻合。     

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.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.