火龙果果实甜菜苷类色素组成与分布

目的：明确火龙果果实中甜菜苷类色素（BLs）组分构成及其部位归属。方法：采用超高效液相色谱飞行时间质谱法对3类火龙果果实\[红皮红肉型（RR）、红皮白肉型（RW）和黄皮白肉型（YW）\]的果肉部位和果皮部位甜菜苷类色素（BLs）进行筛查和结构确证。结果：3类火龙果果实中共鉴定出甜菜苷、丙二酰甜菜苷和梨果仙人掌黄质等19种组分,RR火龙果的果皮部位鉴定的BLs组分最多（14种）,其次是RR果肉部位（12种）及RW果皮部位（9种）。结论：RR火龙果果实BLs组分最为丰富,RW次之,YW最少;BLs主要分布在红色果肉和红色果皮部位,在白色果肉和黄色果皮部位则较少。果肉、果皮部位检测出BLs组分分别为12,16种。     

纤维素酶协同超声波辅助乙醇提取红肉火龙果色素工艺的优化

分别以火龙果果皮、果肉冻干样品为原料,采用响应面法优化纤维素酶协同超声波辅助乙醇提取火龙果果皮、果肉色素工艺。火龙果果皮色素的最佳提取工艺为超声时间24min、超声温度39℃、超声功率325 W、乙醇浓度23%,得率为(81.661 3±0.762 0)mg/100g;火龙果果肉色素的最佳提取工艺条件为超声时间34min、超声温度41℃、超声功率315 W、乙醇浓度23%,得率为(278.660 4±1.084 2)mg/100g。     

火龙果果皮中甜菜红素的提取、鉴定及金属离子对其稳定性的影响

目的:为火龙果源甜菜红素在食品加工中的应用提供理论支持。方法:首先以红肉火龙果果皮为原料，探究浸提液、料液比、浸提液pH值、温度和时间对甜菜红素得率的影响，以优化其提取条件，进而采用UPLC-MS分析纯化后提取物中甜菜红素的含量和结构，最后评价金属离子Cu2+和Fe2+对其稳定性的影响。结果:火龙果果皮中甜菜红素最优提取条件为:采用蒸馏水提取，料液比1∶5，pH 5，温度30 ℃，提取60 min。所得提取物中甜菜红素的含量为95.2 mg/g，含有6种甜菜红素单体，其中，丙二酰甜菜苷和甜菜苷为两种主要单体，分别占46.5%和34.4%。CuSO4和FeCl2干扰甜菜红素的稳定性，即使0.05 mg/mL CuSO4也会造成甜菜红素溶液颜色改变和特征吸光值降低；当FeCl2超过0.10 mg/mL时，甜菜红素溶液的颜色变化趋势加快。结论:红肉火龙果果皮可作为甜菜红素的良好来源，提取工艺简单可行。金属离子Cu2+和Fe2+不利于甜菜红素的稳定性，在加工贮藏过程中应避免与铜制、铁制器具接触。     

红肉火龙果中两种甜菜苷色素稳定性研究

探索红肉火龙果色素稳定性的影响因素,进而确定火龙果色素的最佳储存条件。以红肉火龙果果肉为原料,采用高效液相检测红肉火龙果中5-O-β-葡萄糖-甜菜苷和5-O-β-葡萄糖-异甜菜苷色素含量,研究温度、pH、光照、氮气对其稳定性影响。5-O-β-葡萄糖-甜菜苷和5-O-β-葡萄糖-异甜菜苷色素的热稳定性差,温度越高越不利于色素稳定;pH在4~6时色素最稳定;光照和氧气都可降低色素的稳定性;充氮气有利于色素的稳定性。火龙果饮料等制品的储藏过程中应注意冷藏避光、适宜pH下密封储存,可适量填充氮气。     

两种火龙果果皮红色素提取工艺优化及其抗氧化活性

以红肉红皮(RP)和白肉红皮(WP)火龙果果皮为原料,采用超声波辅助乙醇浸提法提取火龙果果皮红色素,并对其粗提物进行鉴定,通过单因素与正交试验优化提取工艺,同时测定两种果皮红色素提纯物质的总还原能力和自由基抗氧化活性。结果表明,经光谱法和HPLC-MS/MS联用法双重检测,火龙果果皮红色素为甜菜红素。WP中甜菜红素的最佳提取条件为:40%乙醇、料液比1:40 (g/mL)、超声时间25 min、超声温度40 ℃,色素最大得率为0.856%。RP中甜菜红素的最佳提取条件为:40%乙醇、料液比1:30 (g/mL)、超声时间15 min、超声温度30 ℃,色素最大得率为0.915%。RP以其纯化工艺流程获得的提纯物产量是WP的1.232倍。在一定浓度范围内,WP和RP火龙果果皮甜菜红素都有较强的总还原能力,但略低于V_C,清除DPPH·自由基、羟自由基(·OH)的IC₅₀分别为1.15和0.95 mg/mL、5.95和4.57 mg/mL,两者对亚硝酸根(NO₂-)最大清除率分别为22.90%和25.10%,红肉火龙果果皮甜菜红素的综合抗氧化能力优于白肉红皮品种。     

红心火龙果果肉中活性成分与其抗氧化能力的相关性研究

为探讨红心火龙果活性成分与抗氧化能力相关性,以8种红火龙果肉为材料,测定甜菜红素、总酚及黄酮含量,测定总抗氧化、清除DPPH·、ABTS+·、·OH及NO₂-·自由基能力,并进行相关性分析,HPLC和HPLC-MS分离鉴定甜菜红素组分,PLSR研究色素组分含量与抗氧化活性的相关性。结果表明:8个火龙果样品中甜菜红素、总酚和黄酮含量存在差异,"海南金都1号"火龙果甜菜红素和黄酮含量均最高,分别为76.77和9.00 mg/L,"广西大红龙"中总酚含量最高达53.01 mg/L。除·OH清除能力外,甜菜红素与其他4种抗氧化能力呈极显著正相关(r=0.936~0.955)。黄酮与抗氧化能力较显著相关(r=0.717~0.956),而总酚与抗氧化能力无显著相关性(P>0.05)。液质鉴定甜菜红素组分有Betanin、Isobetanin、Phyllocactin和Isophyllocactin,Betanin是抗氧化的重要成分,Phyllocactin其次,可能是Phyllocactin的丙二酰基与苯环邻位酚羟基产生分子内氢键,抑制酚羟基的氧化性。     

HPLC-MS法分离鉴定土人参色素组成

采用液质方法(HPLC-MS),将土人参色素不同组分分离,并对其进行结构鉴定.结果表明:土人参茎和果中色素均为甜菜苷类色素,从土人参茎中分离出五种甜菜苷色素,果中分离出六种,其中五种是二者均有,分别为甜菜苷5-O-β-葡萄糖、甜菜苷6-O-β-葡萄糖、异甜菜苷6-O-β-葡萄糖、2-脱羧基-甜菜苷-6-O-(6’-0-阿魏酰)-β-葡萄糖苷、5,6-二吲哚乙酸-5-O-β-葡萄糖苷.新甜菜苷5-O-β-葡萄糖苷仅存在于土人参果中,在茎中未发现.各组分在土人参茎和果中所占百分数均不同,使二者光谱特征等性质不同.     

红肉与白肉火龙果酚酸组成及其抗氧化活性

为研究火龙果果皮、果肉中的酚酸组成及抗氧化活性,以红肉火龙果和白肉火龙果为研究对象,采用高效液相色谱法(HPLC)测定其游离型酚酸(FPA)、可溶共价结合型酚酸(HPA)和束缚型酚酸(BPA)组分与含量,并测定其体外抗氧化活性,包括DPPH清除能力、还原能力和羟自由基抑制能力。结果表明:两种火龙果中酚酸含量顺序为:红肉果肉 > 白肉果肉 > 白肉果皮 > 红肉果皮。火龙果果肉中酚酸主要以HPA形式存在,果皮中酚酸的主要存在形式为BPA。没食子酸是红肉火龙果中的主要酚酸(1700.70 μg/g干重);原儿茶酸是白肉火龙果中主要酚酸(1877.50 μg/g干重)。红肉果皮的BPA对DPPH自由基清除能力最强(2206.37 mg/L),红肉果肉的HPA还原能力最强(A₇₀₀=0.82),白肉果皮的HPA对羟自由基抑制能力最强(77.50 U/mL)。酚酸含量与抗氧化活性的相关性分析表明:DPPH自由基清除能力和还原能力与酚酸的含量呈极显著(P<0.01)正相关,羟自由基抑制能力与酚酸含量无显著相关性。     

阴香果实花色苷提取工艺研究

阴香成熟果实果皮黑紫色,鲜果花色苷含量1.127%。提取阴香果实花色苷前先将果实煮沸、搅拌。阴香鲜果沸水内煮沸12min,果实裂口率为99%,经搅拌后果肉组织解体、果肉果核分离。阴香果实处理后的物料以70%乙醇溶液、pH3、料液比1∶2(w/v),以温度40℃、浸泡20min浸提花色苷,3次浸提花色苷提取率97.15%。     

火龙果不同部位发酵后活性成分含量和抗氧化活性

以红心火龙果和白心火龙果为原料,测定不同种类和部位火龙果(红心火龙果果肉,red flesh,RF;白心火龙果果肉,white flesh,WF;红心火龙果果皮,red peel,RP;白心火龙果果皮,white peel,WP)发酵液中总酚、总黄酮含量及抗氧化活性(总抗氧化能力、还原能力和羟自由基清除能力),考察酚类物质含量与抗氧化活性的相关性。结果表明:不同种类和部位火龙果发酵液中总酚、总黄酮含量及抗氧化活性存在显著性差异,且RP发酵液表现出最高的总酚(636.63 mg/L)、总黄酮含量(452.42 mg/L)及最强的总抗氧化能力(相当于V_C浓度169.32 mg/L)、还原能力(140.29 mg/L)和羟自由基清除能力(96.65%);总酚、总黄酮含量与总抗氧化能力、还原能力和羟自由基清除能力之间呈正相关,表明总酚类物质是火龙果中抗氧化成分。     

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.