超声波法提取南瓜籽油的工艺条件优化研究

采用超声波法提取南瓜籽油,筛选了提取南瓜籽油的理想溶剂,通过单因素试验和正交试验考察了提取温度、提取时间、液料比、超声频率和功率对南瓜籽油得率的影响,结果表明：石油醚为提取南瓜籽油的理想溶剂;各因素对南瓜籽油得率的影响大小依次为：液料比＞超声时间＞超声温度＞超声频率和功率;优化的提取工艺参数为：液料比6:1(V/W)、超声频率和功率59kHz、280W、提取温度60℃、提取时间35min,此条件下无壳瓜籽油的得率达39.04%。     

超声波提取山楂籽油的技术研究

以山楂籽油的提取率为考察指标,在单因素实验基础上,研究提取时间、料液比、浸提温度以及超声功率4个因素对山楂籽油提取率的影响,并通过正交实验得出最佳提取条件。实验结果表明:影响山楂籽油提取率的四个因素的主次顺序为:超声功率>浸提温度>料液比>提取时间,最佳提取条件为提取时间30 min,料液比1∶10,浸提温度45℃,超声功率200 W。在此条件下通过验证实验得到山楂籽油的提取率为10.61%。     

超声波辅助提取玫瑰茄籽油工艺的研究

本试验以玫瑰茄籽为原料,以石油醚为提取溶剂,采用超声波辅助法对玫瑰茄籽油脂的提取工艺进行研究。利用正交试验探讨超声时间、超声温度、料液比、超声功率对玫瑰茄籽油得率的影响。结果表明影响玫瑰茄籽油得率的因素主次顺序为：料液比〉功率〉温度〉时间;最佳提取工艺条件为：料液比1∶10、超声功率120W、温度50℃、提取时间40min,得率为11.77%。     

超声波强化提取油茶籽油的研究

油荼籽油中不饱和脂肪酸含量丰富,是一种功能性油脂.研究了提取溶剂、液料比、提取时间对超声提取油茶籽油和加热浸提油茶籽油的影响.结果表明,正己烷是较理想的溶剂;适当增加溶剂量、提取时间、超声波功率、提取温度,油荼籽油得率随之增加;在温度40℃、液料比(V/m)6:1、提取时间30 min和超声波功率300 W的条件下进行超声提取,油茶籽油得率为45.23%;对加热浸提来说,在温度60℃、液料比(V/m)7:1、提取时间90 min条件下.油茶籽油得率仅为38.15%.由此可见,超声作用明显降低了提取温度、减少了溶剂用量、缩短了提取时间,而且使油茶籽油得率提高.     

响应面法优化超声波辅助提取樱桃籽油的工艺研究

以异丙醇为浸提溶剂,利用响应面法(RSM)优化超声波辅助提取樱桃籽油的工艺条件。在单因素实验基础上,选取料液比、超声时间、超声温度、超声频率为自变量,以异丙醇为浸提溶剂,樱桃籽油得率为响应值,应用中心组合实验设计方法,研究各自变量及其交互作用对樱桃籽油得率的影响,建立二次多项回归方程预测数学模型。结果表明,料液比、超声频率和超声时间3个因素对樱桃籽油提取率有显著影响。确定超声波辅助提取樱桃籽油的最佳工艺参数为料液比1∶8(g/mL)、超声时间56min、超声温度40℃、超声频率110kHz、超声功率300W,在此条件下,樱桃籽油的油得率达到12.40%。     

苹果籽油提取工艺研究

采用溶剂浸提法和超声波辅助提取法对苹果籽油的提取进行了研究.溶剂浸提法结果表明:石油醚为提取苹果籽油的适宜溶剂,通过单因素和正交试验得出苹果籽油提取的优化工艺条件为:提取温度45℃,提取时间7h,料液比1∶6.超声波辅助提取法的结果表明:超声强化可以降低提取温度、缩短提取时间和节省溶剂用量;超声波功率和提取时间对于苹果籽油的提取均有显著的影响.试验得出,在料液比1∶6条件下,功率为250W和时间25min时提取效果最佳.     

超声波辅助与溶剂萃取枇杷仁油的对比研究

以枇杷仁为原料,对两种提取枇杷仁油的工艺和效果进行比较。通过正交试验得到溶剂法提取枇杷仁油的最佳工艺条件为：溶剂选用石油醚,料液比1：8(g:mL),提取时间2 h,提取温度80 ℃,枇杷仁油提取率为10.3%;超声波辅助法提取枇杷仁油的最佳工艺条件为：溶剂选用石油醚,料液比1：5(g:mL),超声温度60 ℃,超声时间25 min,超声功率180 W,枇杷仁油提取率为12.9%。结果表明,超声波辅助法提取的枇杷仁油得率比溶剂法高,并且超声波辅助法比溶剂法提取的时间短、温度要低,是一种短时高效的提取方法。     

超声波与溶剂萃取西瓜籽油的对比研究

以西瓜籽为原料,对2种提取西瓜籽油的工艺和效果进行比较。通过正交试验得到溶剂法提取西瓜籽油的最佳工艺条件为:溶剂选用石油醚(b.p.60～90℃),料液比1∶8(g∶mL),提取时间2 h,提取温度80℃,西瓜籽油提取率为48.2%;超声波辅助法提取西瓜籽油的最佳工艺条件为:溶剂选用石油醚,料液比1∶6(g∶mL),超声温度50℃,超声时间50 min,超声功率150 W,西瓜籽油提取率为50.8%。结果表明,超声波辅助法提取的西瓜籽油得率比溶剂法高,并且超声波辅助法比溶剂法提取的时间短、温度低,是一种短时高效的提取方法。     

苹果籽油提取工艺研究

本试验采用溶剂浸提法和超声波法对苹果籽油的提取进行了研充。溶剂浸提法结果表明：石油醚为提取苹果籽油的适宜溶剂，通过单因素和正交实验得出苹果籽油提取的优化工艺条件为提取温度45℃、提取时间孙、料液比1：6。采用超声波提取结果表明：超声强化不仅可以降低提取温度、缩短提取时间和节省溶剂耗量，超声波功率和提取时间对于苹果籽油的提取均有显著的影响。试验得出，在料液比1：6条件下，以功率250w和时间25min时提取效果最佳。     

超声波法提取新疆石榴皮皂苷的工艺研究

采用超声辅助溶剂法提取石榴皮总皂苷。以石榴皮总皂苷含量为考察指标,研究了超声时间、超声频率、超声功率及料液比这四个因素对总皂苷含量的影响。选用L9(34)正交表进行正交实验,确定石榴皮总皂苷超声提取的最佳工艺条件为:超声功率400W,超声时间60min,料液比1:60,超声波工作:间歇时间8:6。在最优因素水平组合条件下,齐墩果酸提取率为1.738mg/g。     

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.