花椒提取物对调理猪肉饼冷藏期间品质的影响研究

探究不同添加量的花椒提取物对调理猪肉饼冷藏期间品质及氧化程度的影响。将0.01%、0.02%和0.03%的花椒提取物添加到调理猪肉饼中,研究其在1、4、7、10 d冷藏期间的p H、颜色、质构、硫代巴比妥酸值(thiobarbituric acid reactive substance,TBARS)和巯基值的变化,并与0.02%二丁基羟基甲苯(butylated hydroxytoluene,BHT)作比较。研究结果表明,添加花椒提取物对调理猪肉饼冷藏期间的p H、颜色无显著影响(p0.05),在一定程度上降低了其硬度和咀嚼性。此外,添加花椒提取物可显著降低猪肉饼脂肪氧化和蛋白质氧化程度(p0.05)。当添加量为0.01%和0.02%时,花椒提取物处理组抑制脂肪氧化的效果与0.02%的BHT效果相当,而当添加量增加至0.03%时,花椒提取物组抗脂肪氧化效果优于0.02%的BHT,且其蛋白氧化程度在整个冷藏期间均显著低于对照组(p0.05),表明花椒提取物可有效抑制猪肉饼中脂肪和蛋白质氧化,其中0.03%花椒提取物组效果最好,甚至优于0.02%的BHT。     

花椒提取物对调理猪肉饼品质的影响

以猪肉饼为研究对象,以TBARS值、菌落总数、质构、pH值、出品率和感官评价为指标,以不添加花椒提取物的猪肉饼为对照,研究了猪肉饼中分别添加0.03%、0.06%、0.09%的花椒提取物对冷藏过程中猪肉饼的抗氧化能力、抑菌效果和品质特性的影响,并与添加0.02%合成抗氧化剂BHT的猪肉饼进行比较。结果显示:加入花椒提取物猪肉饼的TBARS值显著低于对照组(p0.05),并且随着冷藏时间的延长,各处理组的TBARS值都有明显升高的趋势(p0.05);添加0.09%花椒提取物的猪肉饼冷藏0,12天时的弹性和可恢复形变明显高于对照组(p0.05);感官指标在冷藏0,8天时均呈现出先升高后降低的趋势,其中加入0.06%提取物的得分最高,抑菌效果好。花椒提取物的添加对产品得率无明显影响;各组pH值在冷藏期间都呈现出先升高再降低的趋势。总的来说,花椒提取物在猪肉饼中起到了良好的抗氧化和抑菌作用,可以在一定程度上提高肉饼质量。     

八角茴香提取物抗氧化的研究

文章采用八角茴香为原料,以乙醇为溶剂,经超声波提取得八角茴香提取物。通过正交试验获得最佳提取条件,然后对提取物DPPH自由基清除能力和提取物对猪油抗氧化作用进行了研究。实验表明:最佳提取条件为乙醇浓度90%、料液比1∶12、超声波处理时间70 min、浸泡时间12 h,也证明了提取物具有DPPH自由基清除能力,随着浓度的增加,提取物对DPPH.自由基的清除能力逐渐增强,但对DPPH自由基的清除率低于BHT,此外提取物对猪油的自动氧化也有明显抑制作用,当提取物添加量为油样的0.15%时,其抗氧化效果与0.02%BHT相当。     

中国沙棘乙醇提取物的体外及对HepG2细胞的抗氧化活性

本文从生化角度全面分析了中国沙棘乙醇提取物的体外抗氧化活性,并在评价细胞毒性的基础上,以Hep G2细胞为模型,利用流式细胞仪评估了提取物的细胞抗氧化能力。结果表明,中国沙棘乙醇提取物对ABTS自由基具有良好的清除效果,当浓度为5 mg/m L时,其清除能力与阳性对照BHT相当;中国沙棘乙醇提取物对NO自由基也有良好的清除效果,但其整体清除能力不及BHT;当浓度为5 mg/m L时,中国沙棘乙醇提取物对亚油酸脂质过氧化表现抑制,但其抑制效果低于BHT;中国沙棘乙醇提取物的总抗氧化能力随浓度的增大而增强,当浓度为5 mg/m L时,其总抗氧化能力与同浓度下的BHT接近。在浓度为0.05~5 mg/m L范围内,中国沙棘乙醇提取物对Hep G2细胞不显示毒性;当处理浓度为0.5、1、5 mg/m L时,中国沙棘乙醇提取物的阳性细胞率与阳性对照相比分别降低了75.22%、72.36%和78.2%。中国沙棘乙醇提取物不仅在体外条件下具有良好的抗氧化活性,而且在Hep G2细胞内表现出良好的抗氧化能力。     

花椒总多酚的提取及DPPH自由基清除效果研究

以花椒为原料,研究不同浓度的甲醇、乙醇和丙酮3种溶剂对花椒多酚提取得率的影响,以及多酚粗提取物清除DPPH自由基能力。结果表明,不同浓度的溶剂对多酚得率影响差异较大,在同等浓度条件下,甲醇的得率最低,丙酮得率最高。又对超声辅助提取时间进行比较,结果显示,40%的丙酮溶液超声提取60 min花椒多酚得率最高,可达5.72%。蒸发溶剂后的粗提物中总酚含量可达30.93%。DPPH自由基清除试验表明,花椒总酚具有较强的抗氧化性,自由基清除率和2,6-二叔丁基-4-甲基苯酚(BHT)相当。     

鸭跖草抗氧化成分提取及其活性研究

采用1：2的氯仿：甲醇超声提取鸭跖草成分，并用石油醚、乙酸乙酯和正丁醇依次进行萃取，利用DPPH法、α-脱氧核糖法和铁氰化钾还原法进行抗氧化实验。同时与BHT和没食子酸（GA）2种合成抗氧化剂进行对照。结果显示乙酸乙酯提取物（EAF）具有较高的抗氧化活性。对其进行硅胶柱层析分离，得到6种纯化的组分（EAF1～EAF6），其中EAF4具有最高的抗氧化活性，在实验所测4个浓度下，清除DPPH自由基能力均比BHT强，在10μg／ml和50μg／ml浓度时，比GA强。其清除羟自由基能力在所有测定浓度下均比2种人工合成抗氧化剂强。其还原能力在所有测定浓度下均比BHT强，但比GA弱。     

花椒油树脂抗氧化作用的研究

以花椒为原料,提取花椒油树脂。通过正交试验获得最佳提取条件,然后对花椒油树脂清除DPPH.自由基和过氧化氢的能力进行了研究。试验表明：最佳提取条件为乙醇浓度70%、浸提温度60℃、原料粒度50目、料液比1∶l0;花椒油树脂具有清除DPPH.自由基和过氧化氢的能力,随着浓度的增加,花椒油树脂对DPPH.自由基和过氧化氢的清除作用逐渐增强,对DPPH.自由基的清除率低于BHT,而对过氧化氢的清除率高于BHT。     

三种香辛料提取物的抗氧化活性研究

主要研究了丁香、桂皮和花椒三种香辛料的抗氧化活性.实验结果表明:三种香辛料提取物对DPPH自由基的清除效果较BHT好,三种香料提取物清除过氧化氢效果较好.     

紫花地丁乙醇提取物的抗氧化性研究

研究紫花地丁乙醇提取物的抗氧化性,将其分别添加到猪油和菜籽油中,利用POV法测定其对油脂的抗氧化作用,同时利用清除DPPH·法测定其清除自由基的能力。结果表明:紫花地丁乙醇提取物对猪油的抗氧化效果明显,1.5%的乙醇提取物的抗氧化效果强于0.02%Vc,略差于0.02%VE;对菜籽油的抗氧化实验表明,1.5%的乙醇提取物强于0.02%Vc和0.02%VE;随着乙醇提取物溶液浓度的增加,清除DPPH·的能力也增强。1.5%的乙醇提取物溶液清除DPPH·能力比0.02%Vc和0.02%VE强。紫花地丁乙醇提取物可有效地延缓油脂的脂质过氧化反应,且清除DPPH·的能力较强,可为应用于医药、食品、化妆品提供依据。     

肉桂提取物抗菌及抗氧化的研究

采用肉桂为原料,以乙醇为溶剂,经超声波提取得肉桂提取物。通过正交试验获得肉桂最佳提取条件,通过体外抗菌试验探讨肉桂提取物的体外抗菌作用,然后对提取物DPPH.自由基清除能力和提取物对花生油抗氧化作用进行了研究。实验表明:肉桂最佳提取条件为粒度80目、料液比1∶12、超声波处理时间60 min、浸泡时间8 h;提取物菌对细菌、霉菌和酵母均有一定的抗菌作用,还具有DPPH.自由基清除能力,随着浓度的增加,肉桂提取物对DPPH.自由基的清除能力逐渐增强,但在相同用量下对DPPH.的清除效果不如BHT溶液,此外提取物对花生油的自动氧化也有明显抑制作用,肉桂提取物添加量为油样的0.2%时,抗氧化作用比0.02%BHT的效果要好。     

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.