杏仁油的亚临界萃取工艺及成分的GC-MS分析

为研究亚临界萃取杏仁油的最佳工艺参数,选择杏仁为原料,研究萃取时间、萃取温度、料液比和萃取次数对杏仁油出油率的影响,并对提取的油脂的成分进行GC-MS。结果表明,亚临界萃取杏仁油的最佳工艺参数为:萃取时间28 min,萃取温度40℃,料液比1∶5(g/mL),萃取3次,在此条件下,出油率达51.7%±0.6%;GC-MS分析表明,亚临界萃取的杏仁油不饱和脂肪酸含量达到91.3%,其中油酸质量分数68.5%、亚油酸质量分数22.8%。因此,采用亚临界萃取杏仁油是一种萃取高质量杏仁油的适宜的方法。     

亚临界萃取法提取文冠果籽油工艺研究

以亚临界萃取法为提取方法 ,文冠果籽油提取率为评价指标,选择原料粒度（A）、萃取温度（B）、萃取时间（C）和萃取次数（D）为考察因素,采用正交试验L9（34）优选文冠果籽中油脂的最佳提取工艺。结果表明：亚临界萃取法提取文冠果籽中油脂的最佳提取工艺条件为原料粒度60目、萃取温度30℃、萃取时间30min和萃取次数3次,文冠果籽油提取率为95.4%。为亚临界萃取技术应用于文冠果籽油提取工业提供理论指导及依据。     

丹参红色素的亚临界水萃取工艺

利用亚临界水萃取丹参药材中的丹参红色素。以丹参酮Ⅱ -A 的提取率作为丹参红色素提取率的考察指标,通过单因素试验研究在丹参红色素的亚临界水萃取过程中萃取温度、萃取时间、物料粒径、液固比、提取剂乙醇体积分数因素对丹参红色素提取率的影响。在单因素试验结果的基础上,选择萃取温度、萃取时间、物料粒径、液固比4 个因素进行正交试验,确定丹参红色素的最佳亚临界水萃取工艺。结果表明：4 个因素对丹参红色素提取率影响的主次顺序为温度>物料粒径>料液比>时间;最优组合为A3B1C1D3,即萃取温度200℃、物料粒径40～60目、液固比25:1(mL/g)、萃取时间10min。在此最优组合基础之上,选择体积分数15% 乙醇溶液作为萃取溶进行萃取,此时所得色素提取率最高为0.319%。     

大叶紫薇种籽油的亚临界萃取工艺及品质分析

对亚临界萃取大叶紫薇种籽油的最佳工艺及油脂品质进行分析。其最佳工艺参数为萃取温度40℃、萃取时间32 min、料液比1∶4 (g/mL)、萃取4次,在此条件下,油脂提取率达97.2%±0.5%,亚临界萃取与超临界萃取的大叶紫薇种籽油理化特性差异不显著。表明采用亚临界萃取大叶紫薇种籽油是一种适宜的提取方法。     

水剂法提取双低菜籽脱皮冷榨饼中油脂和蛋白质的研究

利用水剂法对双低菜籽脱皮冷榨饼中的油脂和蛋白质进行同步提取。在单因素实验基础上,固定浸提时间120 min,选取浸提温度、浸提pH、料液比、物料粒径为考察因素,以油脂提取率和蛋白质提取率为评价指标,采用正交实验优化得到最佳水剂法提取工艺参数为:浸提温度60℃,浸提pH 9,料液比1∶7,物料粒径100~120目。在最佳提取条件下,油脂提取率为64.59%,蛋白质提取率为59.63%。     

亚临界萃取牡丹籽油的工艺研究

以牡丹籽为原料、亚临界丁烷为萃取溶剂、牡丹籽油萃取率为评价指标,选择萃取次数、萃取温度、萃取时间、料液比为考察因素,采用正交试验优化亚临界萃取牡丹籽油的最佳工艺条件。结果表明:亚临界萃取牡丹籽油的最佳工艺条件为萃取温度40℃、萃取时间40 min、萃取次数4次、料液比1∶2,在此条件下,牡丹籽油萃取率为95.16%。牡丹籽油中油酸、亚油酸、亚麻酸含量分别为25.67%、22.48%、44.82%。     

亚临界丁烷萃取澳洲坚果油的工艺及品质研究

为提高澳洲坚果的出油率,采用亚临界丁烷萃取技术提取其油脂,优化温度、时间、料液比、萃取次数等工艺参数,并分析其主要理化指标及脂肪酸组成等品质指标。结果表明,亚临界丁烷萃取澳洲坚果油的最佳工艺参数为:萃取温度45℃、萃取时间15 min、料液比1∶5 g/m L、萃取4次,该条件下澳洲坚果油得率可达80.7%。所制备的油脂品质好,可省去大部分精炼工序;脂肪酸组成以油酸(58.99%)和棕榈油酸(17.59%)为主,并含少量的棕榈酸(9.29%)和硬脂酸(4.15%)。上述结果表明,亚临界丁烷提取澳洲坚果油脂具有操作温度低、产品质量优良的特点。     

响应面法优化亚临界萃取冰岛刺参内脏油脂工艺

以富含脂类活性物质的冻干冰岛刺参内脏为原料,建立亚临界萃取冰岛刺参油脂新工艺。结果表明,亚临界萃取的最佳萃取工艺为料液比(m冰岛刺参∶V萃取液)1∶3(g/mL)、萃取压强0.4 MPa、萃取次数5次、萃取时间56.18min、萃取温度48.55℃,油脂萃取率为23.38%。通过对比不同方法萃取的油脂理化指标及气相色谱—质谱(GC-MS)图,亚临界法萃取的油脂理化指标均优于其他方法,油脂中EPA含量达40.7%,说明亚临界法萃取冰岛刺参油脂的工艺效率高,油脂品质更稳定。     

响应曲面优化余甘子多酚的亚临界水萃取工艺及其抗氧化性研究

以余甘子干果粉为原料,研究亚临界水萃取余甘子多酚的工艺条件及其抗氧化活性。通过单因素试验探讨了亚临界水萃取余甘子多酚工艺中萃取温度、萃取时间、萃取压力和液料比等因素对多酚提取率的影响,利用响应曲面分析法优化提取工艺。最佳优化工艺参数:余甘子干果粉碎过40目筛,纯水80m L,液料比47∶1,亚临界萃取温度212℃,提取11min,余甘子多酚平均提取率17.08%,实测值与预测值符合良好。高效液相分析表明,亚临界水萃取样品中没食子酸提取率达3.284%,远高于溶剂回流提取。体外抗氧化活性研究表明,亚临界水萃取余甘子多酚具有一定清除DPPH自由基和羟基自由基的能力,其IC50值分别为7.05μg/m L和54.35μg/m L,小于TBHQ和溶剂回流提取样品。体现了亚临界水萃取具有较好的选择性、快速、高效、环境友好等优点。     

亚临界萃取羊毛脂工艺的响应面法优化

为提高羊毛脂的回收率,以原羊毛为原料从中提取羊毛脂,研究了亚临界萃取羊毛脂过程中不同萃取条件下的提取率。分别考察了亚临界溶剂选择、萃取温度、萃取时间、萃取次数及料溶比等因素对羊毛脂萃取率的影响,并在单因素试验基础上利用响应面法进行优化,得出萃取率最高的工艺条件:温度65℃、时间10 min、料溶比1∶10、萃取5次,萃取率可达到6.03%。考虑到实际生产效益及对纤维性状影响,最终得到亚临界萃取羊毛脂的最佳工艺为:萃取温度50~55℃,萃取3次,萃取率4.63%~4.86%。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.