变性剂及表面活性剂对蛤蟆油粘度影响的研究

研究了变性剂及表面活性剂对蛤蟆油粘度的影响,以蛤蟆油粘度为评价指标,考察不同浓度的尿素、盐酸胍、β-巯基乙醇、SDS、Triton等变性剂及表面活性剂对蛤蟆油粘度的影响。实验结果表明,当尿素、盐酸胍、β-巯基乙醇、Triton、SDS浓度分别为7mol/L、0.2mol/L、3%、2g/mL及8%时,具有最低粘度,其中盐酸胍的作用效果最佳。实验结果为进一步研究其有效成分、提取分离方法及药理活性奠定了基础。     

肝素黄杆菌肝素酶性质的研究

目的研究肝素酶I的理化性质。方法测定肝素酶I的相对分子质量、等电点、紫外吸收光谱、N端序列,以及各种环境因素对酶活性和酶稳定性的影响。结果相对分子质量约为43×103,等电点为8.5。N端序列不能测到。酶的最适催化条件为:温度45℃,pH6.4～7.0,离子强度150mmol/L。酶在35℃以上极易失活,在pH7～11之间基本稳定。该酶的最大紫外吸收位于280nm。H2O2(1mmol/L,10mmol/L),NaN3(10mmol/L,100mmol/L),乙腈(1%,10%),1mol/L盐酸胍和1mol/L尿素对酶的活性无影响;1%SDS,4mol/L盐酸胍和4mol/L尿素则使酶完全失活;CaCl2和MgCl2是该酶的激活剂,FeCl2则对该酶的活性具有抑制作用。结论通过实验,测定了肝素酶I的主要理化性质。     

胭脂虫甲壳素的提取工艺研究

本实验对胭脂虫(Dactylopius coccus Costa)色素加工剩余物进行甲壳素提取。结果表明,蛋白质脱除最适条件为NaOH 浓度1.0mol/L,反应温度80℃,时间2h;无机盐脱除最适条件为盐酸浓度1.0mol/L,反应温度50℃,时间60min。     

响应面法优化富锌酵母培养条件

该研究利用双酶复合酶解法和碱溶酸沉法从亚麻籽饼粕中提取亚麻蛋白,探究两种提取方法及不同因素对亚麻蛋白功能性质的影响。结果表明,双酶复合酶解法提取的亚麻蛋白功能性质较碱溶酸沉法更优,且不同因素对亚麻蛋白功能性质具有一定的影响。双酶复合酶解法提取的亚麻蛋白的等电点为4.4,且当pH值11、温度60 ℃、亚麻蛋白含量3.4%和NaCl浓度1.5 mol/L时,乳化性最佳;当pH值11、温度40 ℃、亚麻蛋白含量3.4%和NaCl浓度1.5 mol/L,乳化稳定性最佳;当pH值11、温度60 ℃、亚麻蛋白含量2.8%和NaCl浓度1.0 mol/L时,起泡性最佳;当pH值8、温度60 ℃、亚麻蛋白含量3.4%和NaCl浓度1.0 mol/L时,起泡稳定性最佳;当pH值2、温度20 ℃、亚麻蛋白含量2.2%和NaCl浓度1.0 mol/L时,黏度最佳。     

鲜榨果汁基因组DNA快速提取方法的建立及优化

目的 建立及优化鲜榨果汁基因组DNA快速提取方法。方法 本研究比较了植物 DNA 快速提取试剂盒法、棉签法、纤维素膜片法和滤纸片法 4 种方法提取 15 种鲜榨果汁基因组 DNA 的效果，并筛选不同的提取液和裂解液、优化裂解液中的盐酸胍浓度和果汁基因组提取时间。结果 滤纸片法采用DNA裂解液（6 mol/L盐酸胍、1%聚乙烯吡咯烷酮、50 mmol/L三羟甲基氨基甲烷盐酸盐、20 mmol/L乙二胺四乙酸、21.3 mmol/L曲拉通-X-100；pH 6.4）、DNA漂洗液1（8 mol/L盐酸胍、50 mmol/L三羟甲基氨基甲烷盐酸盐；pH 6.4）和DNA漂洗液2（10 mmol/L 三羟甲基氨基甲烷盐酸盐、100 mmol/L氯化钠；pH 8）即可在 5 min 内从鲜榨果汁中提取得到适用于聚合酶链式反应（polymerase chain reaction，PCR）的基因组 DNA。结论 本研究建立的滤纸片法不需要离心机等昂贵的仪器设备、操作简单、无刺激性气味、无环境条件限制，具有快速、价廉、环保等优点，为果汁基因组 DNA 快速提取与现场鉴定研究提供了参考。     

桑叶蛋白的功能特性研究

采用超声波辅助提取结合盐酸沉析法提取桑叶蛋白,研究pH值、离子强度、蔗糖质量浓度和温度对桑叶蛋白功能特性的影响。结果表明：远离其等电点时,桑叶蛋白具有良好的持水性、溶解度、乳化性及乳化稳定性、起泡性;桑叶蛋白的持水性、溶解度和起泡性与NaCl浓度(0～1.0mol/L)呈正相关,而过高的离子强度(NaCl浓度高于0.6～0.8mol/L)会使桑叶蛋白的乳化性和乳化稳定性下降;蔗糖的加入会增加桑叶蛋白的持水性,但会降低其溶解度和起泡性,对桑叶蛋白的乳化性和乳化稳定性影响不大;桑叶蛋白的吸油性和起泡性与温度(4～80℃)呈正相关,持水性、溶解度、乳化性及乳化稳定性于60℃时最好。     

金属离子对鸡蛋清功能性质的影响研究

为提高蛋清功能性质,使之能更加广泛地应用于食品工业,以鸡蛋清为原料,探讨了金属离子种类和添加量对蛋清起泡性、乳化性、蛋白质溶解度以及黏度的影响。结果表明:当Na Cl浓度为0.03 mol/L时,起泡性达到最大值17.65%;当Mg Cl2浓度为0.05 mol/L时,泡沫稳定性达到最大值58.83%;当Ca Cl2浓度为0.02 mol/L时,乳化活性达到最大值0.720;当Ca Cl2浓度为0.05 mol/L时,乳化稳定性达到最大值27.77 min;当KCl浓度为0.01 mol/L时,蛋白溶解度达到最大值98.31%;当Ca Cl2浓度为0.03 mol/L时,黏度达到最大值163 m Pa·s。添加一定浓度的金属离子有利于提高蛋清的功能性质。     

氯化钠对肌原纤维蛋白与风味物质相互作用的影响

为了阐明氯化钠浓度对肌肉蛋白风味吸附特性的影响和相关原理,选取17种典型性醇类、醛类、酮类和酯类化合物,研究0.0~1.0 mol/L氯化钠浓度对肌原纤维蛋白与上述物质的吸附关系,以及对蛋白结构的影响。结果表明,肌原纤维蛋白的表面疏水性在氯化钠浓度0.0~0.4 mol/L时显著升高,在0.4~1.0 mol/L时显著下降;氯化钠浓度在0.0~0.4 mol/L时α-螺旋和β-折叠转化为β-转角,之后无显著变化;肌原纤维蛋白对醇类吸附很弱,随氯化钠浓度升高,醇类、酮类和醛类吸附性总体降低;酯类吸附性在氯化钠浓度0.0~0.4 mol/L时趋于下降,在0.4~1.0 mol/L时趋于升高。蛋白对醛、酮吸附的下降,前期可能是由于二级结构改变导致席夫碱结合位点被屏蔽,后期可能是由于疏水作用力下降;对酯类的吸附作用变化趋势与疏水性相反,是由于静电相互作用为主要结合力。     

鱼鳞盐酸脱钙过程中胶原蛋白含量的变化

研究了鱼鳞盐酸法脱钙过程中胶原蛋白的变化 ,经过和脱除液中总蛋白的比较可以看出 :当脱除液中盐酸浓度 <0 0 8mol/L时 ,胶原蛋白和总蛋白溶出具有同样的规律 ,即随着酸度的增加而增加 ;当盐酸的浓度 >0 1mol/L时 ,胶原蛋白溶出随着酸度的增加而降低 ,总蛋白仍然随着酸度的增加而增加 ,盐酸浓度为 0 0 8～ 0 1mol/L范围时 ,脱钙液中羟脯氨酸含量最高 ,胶原蛋白溶出最多。     

聚氧乙烯链分布对脂肪醇醚硫酸钠性能的影响

研究窄分布脂肪醇醚硫酸钠(N-AE3S)与常规脂肪醇醚硫酸钠(AE3S)的静态表面张力、接触角、动态表面张力及乳化性能,探究聚氧乙烯链(EO)分布对脂肪醇醚硫酸钠性能的影响。结果表明:N-AE3S在临界胶束浓度1.7×10-4mol/L下可以将表面张力降至28.18 mN/m,且具有更好的润湿性能和乳化性能;当浓度为1.0×10-5、1.0×10-3mol/L时,AE3S和N-AE3S均符合混合动力扩散控制吸附机理。     

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.