基于气相色谱-质谱联用技术的蝎子中脂肪酸与氨基酸的同时提取与分析

为从小分子角度了解蝎子发挥营养及药用功效的物质基础,采用甲基叔丁基醚-甲醇-水体系提取样品,分别通过提取溶剂体系的上层有机相富集全蝎中的疏水化合物,下层水相提取极性小分子。提取物经气相色谱-质谱分析,在非极性组分中检测到30种脂肪酸,70%以上为不饱和脂肪酸;在其极性组分中检测到氨基酸类、有机酸类及糖类等化合物,以氨基酸类化合物为主,占总极性化合物50%以上。这些具有多种生物活性及营养价值的不饱和脂肪酸、氨基酸可能是全蝎发挥药效及食疗作用的物质基础。与文献报道全蝎中脂肪酸组成以饱和脂肪酸为主不同,检测到的脂肪酸主要是油酸和cis-9,cis-12-亚油酸,其次为棕榈酸和硬脂酸。在全蝎中发现的游离氨基酸共有13种蛋白质氨基酸和3种非蛋白质氨基酸,包括7种必需氨基酸(赖氨酸除外)和6种药效氨基酸。该工作为进一步研究全蝎的药用及食用价值提供了物质基础。     

基于广泛靶向代谢组学分析黑老虎种子中氨基酸和脂质组分

为探究黑老虎种子作为新兴植物油料资源的潜力,利用广泛靶向代谢组学技术检测分析其氨基酸和脂质组分。结果表明：在基于鉴定出的代谢物结构配置分类下,黑老虎种子含脂质类、氨基酸及衍生物类化合物分别为121种和89种,前者数量和相对含量(30.7%)在11类成分中最高,后者数量居其次,相对含量(17.8%)位于第三;鉴定出20种基础氨基酸和8种人体必需氨基酸,其中L-脯氨酸、L-天冬氨酸、L-丝氨酸等7种药效氨基酸和L-亮氨酸、L-苏氨酸、L-异亮氨酸、L-苯丙氨酸和L-赖氨酸5种人体必需氨基酸含量较高;黑老虎种子中富含亚油酸、γ-亚麻酸、α-亚麻酸等脂肪酸和以溶血磷脂酰胆碱18∶2和18∶2(2n异构)为主的磷脂。黑老虎种子氨基酸类和脂质类组分丰富,多种高度富集成分具有突出的营养功能、活性作用和药用功效,在优质植物油脂开发等领域具有较高的价值。     

不同规格秋刀鱼肌肉的营养成分分析与品质评价

摘 要: 目的 对比分析不同规格秋刀鱼肌肉的营养价值。方法 参照国家标准方法测定大、中、小3种规格秋刀鱼肌肉的基本营养成分、脂肪酸组成和氨基酸组成, 比较其营养价值。结果 随着秋刀鱼规格的增大, 秋刀鱼肌肉中的粗脂肪含量增大, 而粗蛋白、水分含量减小; 3种规格秋刀鱼肌肉中均检测出18种氨基酸, 氨基酸总量为50.93~59.50 g/100 g, 且谷氨酸含量最高(7.00~8.39 g/100 g); 根据氨基酸评分,第一限制性氨基酸均为缬氨酸; 中规格秋刀鱼肌肉蛋白的必需氨基酸指数最高为88.44, 是良好蛋白源。不同规格秋刀鱼均富含多不饱和脂肪酸(47.23%~49.66%), 其中, 中规格秋刀鱼二十碳五烯酸和二十二碳六烯酸占总脂肪酸的比例最高为27.56%。结论 3种规格的秋刀鱼均属于高蛋白、高脂肪鱼类, 氨基酸和脂肪酸种类丰富且比例适中; 中规格秋刀鱼必需氨基酸指数最高, 二十碳五烯酸和二十二碳六烯酸的比例也最高, 营养价值相对较高。     

基于非靶向代谢组技术研究不同发酵温度酱油中代谢产物差异

采用基于超高效液相色谱串联质谱的非靶向代谢组技术,对不同发酵温度(25、30、35和40 ℃)的酱油样品进行了分析。结果表明,4种不同发酵温度酱油样本共鉴定出14 类226个代谢物。其中,25 ℃下发酵酱油中生物碱和有机酸类化合物的含量最高,而35 ℃发酵酱油的中氨基酸、糖类和脂肪酸类化合物的相对含量最高。通过正交偏最小二乘法分析研究,鉴定出了37种显著差异代谢物质(VIP > 1),包括有氨基酸 9 种,糖类和有机酸各5种,生物碱和脂肪酸各4种,芳香类化合物3种,香豆素类、胺类和酚类各2种,黄酮类1种。本研究对不同发酵温度对酱油代谢物和品质调控提供理论参考。     

南疆杏仁酸类化合物及其营养品质分析

采用气相色谱-质谱联用技术和高效液相色谱法对88份南疆杏仁有机酸和氨基酸进行测定，为南疆杏仁营养品质评价提供理论依据。结果表明：杏仁中总有机酸含量分布在23.75～11 446.19μg/g之间，其中，苹果酸含量最高，占总有机酸的46.66%，是南疆杏仁中酸类化合物的主要成分，其次是草酸（14.67%）和柠檬酸（12.06%），葡萄糖酸含量最低，占有机酸的0.05%。不饱和脂肪酸以油酸含量高，占总脂肪酸含量的59.91%，饱和脂肪酸以棕榈酸含量高，占总脂肪酸含量的12.57%。样本中共检测到15种氨基酸，总氨基酸含量为79.55～4 464.17μg/g，必需氨基酸含量为21.62～1 248.35μg/g。通过主成分分析表明，杏仁中酸类化合物含量的前8个主成分累计方差贡献率达85.05%，苹果酸、柠檬酸、缬氨酸、苏氨酸、谷氨酰胺、丝氨酸、油酸、亚油酸、丁二酸和乙酸是鉴定杏仁品质的重要指标。基于31种极性代谢产物进行聚类分析：可将样本聚为Ⅳ大类，第Ⅰ类包含8份杏仁材料，主要涵盖以苹果酸含量、脂肪酸、谷氨酸含量高的类型；第Ⅱ类包含77份杏仁材料，主要涵盖以苹果酸、脂肪酸含量中等，氨基酸含...     

不同地区稻田小龙虾的营养品质比较研究

以来自江苏、安徽、湖北地区的稻田雄性小龙虾为研究对象,对其含肉率、基本成分、矿物质、氨基酸和脂肪酸组成进行分析,评估并比较不同地区稻田雄性小龙虾的营养价值。结果表明,湖北小龙虾的含肉率（11.65%）和粗蛋白（19.04%）含量最高,江苏小龙虾的粗脂肪含量最高（1.10%）。3 个地区小龙虾肉中均检出17 种氨基酸,必需氨基酸含量/总氨基酸含量比为38%～39%,说明虾肉的蛋白质质量较好,其中安徽小龙虾的总氨基酸含量最高。3 个地区的小龙虾中,安徽小龙虾虾肉中的矿物质总量最高,为850.92 mg/100 g,其中Na、K、Ca、P、Fe、Cu含量显著高于其余两地（P＜0.05）。从虾肉的脂肪酸组成来看,江苏小龙虾所含脂肪酸种类最丰富,安徽和江苏小龙虾虾肉中的脂肪酸以多不饱和脂肪酸为主（相对含量分别为43.15%和41.31%）,而湖北小龙虾虾肉中的脂肪酸以单不饱和脂肪酸为主（45.70%）,3 个地区小龙虾虾肉中的不饱和脂肪酸含量占比均在70%以上。     

不同解冻方式对猪肉营养价值的影响

为了得到对冻结猪肉较为合理的解冻方式,研究比较了空气、冷水、热水、微波、超高压和低温解冻6种方式对猪背最长肌营养价值的影响,测定其常规营养组分、脂肪酸、氨基酸和微量元素含量的变化。结果显示,超高压和热水解冻分别对保持肌肉的粗脂肪和粗蛋白含量较好;超高压解冻后的肌肉PUFA/SFA值为0.21,能有效保证肌肉的脂肪酸营养价值;微波解冻后肌肉中必需氨基酸和非必需氨基酸含量为各组最高,营养价值较高。6种解冻方式中,超高压和微波解冻能较好的保持猪肉的营养价值。     

斑石鲷肌肉营养成分分析

为评价斑石鲷的营养价值,对斑石鲷的含肉率进行了测定,并采用国家标准方法测定了斑石鲷肌肉中的水分、粗蛋白质、粗脂肪、粗灰分、氨基酸、脂肪酸和矿物质元素含量。结果表明,斑石鲷的含肉率为56.1%;肌肉中水分、粗蛋白、粗脂肪和粗灰分的含量分别为78.26%、13.9%、1.48%和1.34%;肌肉中含19种氨基酸,总含量(鲜重)为21.28%,其中必需氨基酸含量为8.83%,占氨基酸总量的39.17%;必需氨基酸与非必需氨基酸含量的比值为64.32%;鲜味氨基酸含量为7.78%,占氨基酸总量的36.58%;肌肉中多不饱和脂肪酸百分比含量为35.24%,DHA和EPA含量分别为12.4%和3.74%;肌肉中矿物质元素Ca,Mg和P的含量分别为720、1510μg/g和9930μg/g,微量元素中锌的含量最高(15μg/g),其次为铁(4.9μg/g)。斑石鲷肌肉中富含必需氨基酸和鲜味氨基酸,且DHA和EPA及矿物质元素含量丰富,因此斑石鲷是营养价值较高的优质食用鱼类。     

几种主要养殖淡水、海水经济鱼类肌肉营养组成及对比分析

采用国家标准方法对我国常见几种养殖鱼类肉中的水分、灰分、蛋白质、粗脂肪、氨基酸、脂肪酸进行测定。研究了其肌肉营养组成,对比分析了几种海水鱼和淡水鱼的营养价值区别,为常见鱼类的加工利用提供基础资料。结果表明:草鱼中肌肉中蛋白质和灰分含量最高;大黄鱼的水分含量最低,粗脂肪含量最高。就氨基酸总量言(干重计),淡水鱼略高于海水鱼,淡水鱼为72.2%~77.6%;海水鱼为51.5%~69.0%。6种鱼的必需氨基酸与总氨基酸的比值(WEAA/WTAA)为42.4%~43.7%,必需氨基酸与非必需氨基酸的比值(WEAA/WNEAA)为90.9%~94.6%。6种鱼的第一限制性氨基酸都是Met+Cys,大菱鲆的EEAI值最高,达90.3,氨基酸营养最均衡。大黄鱼总脂肪酸种类最多,含量最高约占肌肉的10.7%;其脂肪酸中亚油酸与亚麻酸的比值(LNA:ALA)达5.9;EPA和DHA的含量最高,总和占肌肉含量的1.44%,脂肪酸营养价值最高。     

灰褐牛肝菌(Boletus griseus)子实体的营养评价及蛋白质组分分析

测定灰褐牛肝菌子实体的基本成分、单糖、脂肪酸和氨基酸组成,矿物质含量及其蛋白质连续累进组分的含量,并对其蛋白质的营养价值进行系统评价。结果表明:灰褐牛肝菌子实体中粗蛋白质量分数为28.22%;葡萄糖含量最高,为258.04 mg/g;17种脂肪酸被检出,亚油酸、油酸和棕榈酸分别占脂肪酸总量的35.91%、28.46%和24.50%;游离氨基酸共检出29种,其中Tyr和Ala含量较高,甜味氨基酸和鲜味氨基酸分别占游离氨基酸总量的23.37%和12.69%;水解氨基酸中必需氨基酸含量较高,占氨基酸总量的38%,其氨基酸评分、必需氨基酸指数、生物价、营养指数和氨基酸比值系数分别为71.88、69.93、64.52、19.73和50.05。灰褐牛肝菌富含Mg、Fe、Zn、Cu,同时有毒元素Cd含量相对较高。蛋白质连续累进组分中清蛋白含量最高,占总蛋白的65.62%,但其Cd含量较高,占总Cd量的38.79%。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析表明清蛋白和球蛋白的分子质量分布主要在40 k D,差异热量扫描分析表明其热变性温度分别为125.04℃和75.04℃。结果表明,灰褐牛肝菌子实体的营养价值较高,但是由于Cd元素含量较高,可能存在一定的健康风险。     

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.