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%。     

超声波辅助与溶剂萃取番木瓜籽油的比较研究

以番木瓜籽为原料,对2种提取番木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番木瓜籽油的最佳工艺条件为:溶剂选用石油醚,料液比1∶8(g∶m L),提取时间2 h,提取温度80℃,番木瓜籽油提取率为35.8%;超声波辅助法提取番木瓜籽油的最佳工艺条件为:溶剂选用石油醚,料液比1∶4(g∶m L),超声温度50℃,超声时间20 min,超声功率120 W,番木瓜籽油提取率为38.8%。结果表明,超声波辅助法提取的番木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。     

苹果多酚浸提方法的研究

苹果多酚是一类具有强抗氧化性的物质，本文主要研究了有机溶剂浸提法和超声波浸提法两种方法在从苹果粉中提取多酚方面的异同，影响因素主要包括提取溶剂、温度、时间、料液比、提取次数。结果表明，有机溶剂提取苹果多酚的最佳工艺参数为：70％的乙醇-水混合溶液按1：20的料液比，在30℃水浴中浸提两次，每次处理30min。超声波提取苹果多酚的最佳工艺参数为：70％的乙醇-水溶液按1：30的料液比在冰浴中用超声波处理两次，每次处理时间为15min。在同样的提取条件下，超声波浸提得率远高于有机溶剂浸提得率。     

石榴籽油提取工艺的研究

以石榴籽为原料,利用超声波辅助有机溶剂提取石榴籽油,在单因素试验的基础上,通过正交试验研究了料液比、提取时间、提取温度、超声波功率对石榴籽油得率的影响,确定了超声波辅助提取石榴籽油的最佳工艺条件。结果表明,石榴籽油的最佳提取工艺条件为:料液比1∶20,提取时间40 min,提取温度50℃,超声波功率400 W。在该条件下石榴籽油得率为21.77%。     

侧柏籽油的超声辅助提取及其脂肪酸组成分析

以环己烷为提取溶剂,采用响应面法(RSM)优化超声波辅助提取侧柏籽油的工艺条件,在单因素试验基础上,选取液料比、提取时间、提取温度、超声波功率为影响因素,以侧柏籽油提取率为响应值,应用中心组合试验设计(central composite design,CCD)建立数学模型,进行响应面分析,并采用GC-MS 测定侧柏籽油的脂肪酸组成。结果表明,提取侧柏籽油的优化工艺条件为：液料比7:1(mL/g)、提取时间38min、提取温度55℃、超声波功率270W,在此工艺条件下,侧柏籽油提取率为93.47%;GC-MS 测定结果表明侧柏籽油中富含不饱和脂肪酸,总含量达到84.37%,其中油酸、亚油酸和亚麻酸的含量分别为28.41%、11.40% 44.56%。     

苹果籽油的超声波辅助提取条件优化

以苹果籽为原料,以传统的索氏提取法为参照,采用超声波法辅助提取苹果籽油,研究超声功率、超声时间、超声温度、溶剂用量和物料粒度等单因素对苹果籽出油率和提取率的影响,在单因素的基础上,优化超声波辅助提取条件,并分析苹果籽油的脂肪酸组成,结果表明在粉碎粒度为50目、超声温度45℃、溶剂液料比7:1(mL:g)、超声功率为400 W、超声时间为30 min的条件下苹果籽油的出油率和提取率最高.GC-MS分析表明苹果籽油主要含不饱和脂肪酸,以亚油酸、油酸、棕榈酸为主,三者的含量总和占总脂肪酸总量的93%,索氏法和超声辅助法获得的油的成分没有明显差异.     

响应面法优化微波辅助提取海蓬子籽油工艺

以成熟海蓬子种子为原料、石油醚为提取溶剂,采用微波辅助法提取海蓬子籽油。在微波温度、微波时间、料液比和微波功率对海蓬子籽油得率影响4 个单因素试验的基础上,通过响应面法优化微波辅助提取海蓬子籽油的最佳工艺条件。结果表明,微波辅助提取海蓬子籽油的最佳工艺条件为：微波温度55 ℃、微波时间5 min、料液比1∶10（g/mL）、微波功率700 W。在此条件下,海蓬子籽油得率为32.58%。与传统索氏抽提法相比,微波辅助提取海蓬子籽油的得率提高了0.15%,而提取时间仅为索氏抽提法的1.39%。     

超声波提取火棘籽油的工艺研究

利用超声波从火棘籽中提取火棘籽油,此法有良好的提取率。正交试验考察了超声波功率、提取时间、料液比以及提取温度对提取率的影响,得出最佳提取条件为超声波功率250 W,提取时间40 min,提取温度45℃,料液比1∶8(g∶mL),在此条件下火棘籽油的提取率为7.66%。     

超声波辅助提取花椒籽油的工艺研究

为了提高花椒的经济价值,充分利用花椒籽中的花椒籽油,以脱蜡花椒籽为原材料,利用超声波辅助提取花椒籽油.首先,通过预处理试验确定最佳提取溶剂,然后,通过单因素试验对影响花椒籽油得率的因素(液料比、提取时间、提取温度、超声波功率)进行探讨.最后,采用Box-Behnken中心组合试验设计原理,以油脂得率为考察指标,对液料比、超声功率、提取时间进行3因素3水平响应面分析,确定了在该试验中超声波辅助处理提取花椒籽油最佳工艺参数:液料比:21.5∶1 (mL/g),提取时间:25 min,提取温度:60℃,超声功率350 W.在此条件下,花椒籽油得率为27.25％.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

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.