浸提法提取杏仁油工艺参数优化

以苦杏仁为原料,采用有机溶剂浸提法对提取杏仁油参数进行了优化。通过单因素试验和正交试验,探讨了不同因素对浸提法提取杏仁油提取率的影响,确定了正己烷提取杏仁油的最佳提取参数。结果表明:苦杏仁中的脂肪含量49.58%,各因素对杏仁油提取率的影响程度由大到小依次是料液比、提取温度、提取时间、溶剂浓度。正己烷提取杏仁油的最佳工艺参数:料液比1∶11,浸提温度65℃,浸提时间2h,溶剂浓度60%。在此条件下,杏仁油的提取率为90.02%。     

杏仁油的提取及精炼

主要阐述了杏仁油的提取工艺、精炼工艺和参数。选用正已烷作为提取杏仁油的溶剂，通过研究料液比、浸提时间、浸提温度、浸提次数对杏仁油提取率的影响，得出杏仁油的最佳提取条件是：料液比为1：12、浸提温度60℃、浸提时间60min、浸提2次。并针对杏仁油的特性进行试验，通过精炼加工，去除异常滋味、气味，制得清香透明的高级精炼杏仁油。     

超声波辅助提取雪莲果中低聚果糖及其纯化的初步研究

以雪莲果为原料,用超声辅助提取低聚果糖,由单因素试验和正交试验确定的最佳提取工艺参数为提取时间3h、提取温度85℃、超声时间5min、料液比1:10(g/g)。在此条件下,多糖的提取率为4.257%。由单因素试验和正交试验确定的最佳脱色工艺参数为活性炭添加量2%,脱色温度80℃,脱色时间50min,脱色pH3.5。在此条件下所得脱色液的透光率为97.86%。     

新鲜菊苣提取和纯化菊粉的工艺

研究比色法测定菊粉含量的方法,并采用正交设计优选了从新鲜菊苣根中热水浸提菊粉的提取工艺条件和脱蛋白以及脱色的最佳条件。实验结果表明,菊粉提取的最佳工艺条件为:料液比1∶1,浸泡时间40 min,加热浸提温度为100℃,加热浸提时间40 min,菊粉的提取率达14.74%;脱蛋白时菊液与活性炭的最佳比例为1∶1.5;提取液最佳脱色工艺条件为:脱色温度70℃,脱色时间50 min,活性碳用量为30 g/L,脱色率为74.36%。     

车前草多糖的提取及纯化工艺研究

采用热水浸提法提取车前草水溶性多糖并对其进行纯化.通过单因素和正交试验得出,车前草多糖提取的最佳工艺条件为浸提时间2 h,浸提温度80 ℃,料水比1:25;脱色的最佳工艺条件为温度60 ℃,脱色时间40 min,活性炭用量1%;采用木瓜蛋白酶法、三氯乙酸法及Sevag法脱除车前草多糖浓缩液中的蛋白质,实验结果表明,木瓜蛋白酶法脱蛋白率最高为61.16%、多糖损失率最低为     

杏仁脱皮去苦及杏仁油脱色研究

采用正交实验方法研究杏仁脱皮去苦及杏仁油脱色,从中筛选出最佳工艺参数。在沸腾的pH值为9的碱液中浸泡5min杏仁脱皮效果好;在pH值为4的35℃的酸性溶液中浸泡36h,可以完全去除苦杏仁的苦味;粗制杏仁油脱色,用自制的脱色剂,油剂比20∶1,在85℃下搅拌5min后过滤可获得微黄透明的脱色杏仁油。     

紫番薯色素的提取及稳定性研究

通过单因素试验对色素的最大吸收波长、最佳提取溶剂、料液比、水浴温度以及浸提时间等进行探讨,正交试验研究最佳提取工艺条件,并对色素的稳定性进行研究.得到了最佳提取工艺条件为,10%的柠檬酸,料液比为1:10,浸提时间为1.5 h,提取温度为40℃.稳定性研究表明,紫番薯色素对H2O2、Na2SO3以及光线表现出不稳定性,...     

洋葱杜仲山葡萄酒的研制

以洋葱、杜仲、山葡萄酒为原料,经过浸提、调配、冷冻处理等工艺,采用了正交设计试验确定了洋葱杜仲山葡萄酒的最佳工艺条件和配方。结果表明:杜仲浸提液的最佳工艺条件:杜仲与乙醇比为1∶10,浸提温度60℃,浸提时间1.5h。洋葱杜仲山葡萄酒口味最佳配比,洋葱浸提液添加量10%,杜仲浸提液添加量2%,加糖量10%。洋葱杜仲山葡萄酒稳定性的最佳处理为果胶酶加量0.02g/100mL,酶解温度50℃,酶解时间1.5h。洋葱杜仲山葡萄酒最佳冷冻条件:冷冻温度-6℃,冷冻时间7d。     

碱溶酸沉法提取籽粒苋蛋白质的工艺优化

采用单因素试验及响应曲面试验,研究了浸提液pH,温度,浸提时间,料液比对籽粒苋蛋白质提取率的影响,确定了碱溶酸沉法提取籽粒苋蛋白的最佳工艺参数。结果表明影响籽粒苋蛋白质提取率的主次因素依次为:pH>浸提时间>料液比>提取温度。当pH为10,温度为40℃,浸提时间为107 min,料液比为1∶19时,籽粒苋蛋白质的提取率最高,可达71.83%。     

从脱脂豆粕中提取大豆低聚糖的工艺研究

以脱脂豆粕为原料,经过碱液浸提,酸沉淀蛋白,活性炭脱色,离子交换脱盐,减压蒸馏浓缩,乙醇沉淀,离心,烘干等工序,提取并分离大豆低聚糖产品。主要对大豆低聚糖的浸提工艺、脱色工艺和脱盐工艺进行优化,确定各工艺的最好条件。大豆低聚糖浸提的最佳工艺条件为:1%Na_2CO_3溶液,浸提温度55℃,浸提时间1.5 h;大豆低聚糖脱色的最佳工艺条件为:活性炭用量1.5%,pH 3,脱色温度50℃,脱色时间30 min;大豆低聚糖脱盐的最佳流速为0.05 cm~3糖液/(cm~3树脂柱·min)。采用此工艺可从10 g脱脂豆粕中得到0.565 g大豆低聚糖产品。     

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.     

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.     

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.     

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.     

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.