白刺籽油的萃取及理化性质和脂肪酸组成分析

以西伯利亚白刺籽为原料,应用超临界CO2流体萃取白刺籽油,采用正交试验研究了压力、温度、时间等对萃取效果的影响,确定了萃取白刺籽油的最佳条件:压力30 MPa,温度30℃,时间150 min.对超临界萃取的白刺籽油进行了理化性质及GC/MS分析,结果显示,酸价为3.36 mgKOH/g、过氧化值为0.48g/100 g、碘值为143.2 g/100 g、皂化值为196 mg/g、水分及挥发物含量为0.12 g/100 g,其中共检测出11种脂肪酸,占总脂肪酸质量的70.75％,说明超临界CO2萃取的白刺籽油工艺稳定可靠,并具有极高的应用价值,为进一步开发利用白刺提供了参考依据.     

碱蓬籽油的超临界CO2流体萃取及其GC/MS分析

应用超临界CO2萃取技术，研究了碱蓬籽油的提取工艺，采用四因素三水平正交试验，考察了压力，温度，萃取时间、CO2流量四因素对碱蓬籽油萃取率的影响，研究得出最佳萃取条件为：压力25MPa，温度42．5℃，时间3h，CO2流量25kg/h。利用GC／MS分析了碱蓬籽油的组成成分，比较了超临界CO2萃取油样和乙醚萃取油样的理化性质。     

超临界CO_2萃取西伯利亚白刺籽油工艺研究

以西伯利亚白刺籽油的收率为评价指标,在单因素实验基础上,采用L9(34)正交实验优化白刺籽油的超临界CO2萃取工艺条件,并用GC-MS对最佳工艺条件萃取的白刺籽油脂肪酸成分进行分析。结果表明:超临界CO2萃取白刺籽油的最佳工艺条件为萃取压力40 MPa,萃取温度55℃,CO2流量10 L/min。从白刺籽油中分离并鉴定出8种成分,其中不饱和脂肪酸以亚油酸(65.671%)和油酸(25.747%)为主,占总含量的90%以上。     

超临界CO_2流体萃取核桃油研究

本文研究应用超临界CO2流体萃取技术提取核桃油工艺。采用四因素三水平正交试验,考 察压力、温度、萃取时间、CO2流量四因素对核桃油萃取率影响效果。最佳萃取条件为:压 力30 Mpa,温度50℃,时间4h,CO2流量25kg/h,在此条件下萃取率可达52.4％。利用 GC/MS分析核桃油成分组成,比较超临界CO2萃取油样和乙醚萃取油样的理化性质。     

玉米胚芽油的超临界CO2萃取

研究了超临界CO2流体萃取玉米胚芽油的条件,着重研究了萃取压力、温度、萃取时间和CO2流量对油脂萃取率的影响,优化了萃取工艺条件;萃取压力35MPa,温度50℃,时间3h,CO3流量34kg/h,并利用GC／MS分析了最佳条件下萃取的玉米胚芽油成分组成。并比较了超临界CO2萃取的玉米胚芽油样和乙醚萃取油样的理化性质。     

超临界CO_2流体萃取琉璃苣籽油及其脂肪酸分析

利用超临界CO2流体萃取技术萃取琉璃苣籽油,考察了萃取压力、萃取温度、萃取时间和CO2流量对琉璃苣籽油出油率的影响,并通过正交试验确定了超临界CO2萃取琉璃苣籽油的最佳工艺条件。研究结果表明,超临界CO2萃取琉璃苣籽油的最佳工艺条件为:萃取压力25 MPa,萃取温度45℃,萃取时间2.5 h,CO2流量45 L/h。在此条件下,出油率为28.08%。气相色谱对琉璃苣籽油的脂肪酸组成分析表明,琉璃苣籽油富含油酸、亚油酸和γ-亚麻酸。     

乌桕籽皮油超临界CO2流体萃取及其成分分析

应用超临界CO2 流体萃取技术,研究了乌桕籽皮油的萃取工艺。采用正交试验,考察了萃取压力、温度、CO2 流量三因素对乌桕籽皮油萃取率的影响效果。最佳萃取条件确定为：压力40MPa,温度36℃,CO2 流量20L/h,时间1h。利用GC 分析了乌桕籽皮油的成分组成,以期为乌桕籽的综合利用提供理论依据。     

超临界CO2萃取疯树籽油工艺的响应面优化

采用超临界CO2流体技术对麻疯树籽油进行萃取,运用响应面法优化了萃取工艺条件。结果表明,超临界CO2萃取麻疯树籽油的最佳工艺条件为:原料粒度20目,萃取压力37 MPa,萃取温度44.5℃,CO2流速30 L/h,萃取时间120 min,夹带剂(95%乙醇)用量为原料质量的40%,在此条件下,麻疯树籽油提取率可达93.13%。将超临界CO2萃取的麻疯树籽油与螺旋压榨法提取的麻疯树籽油品质进行分析比较,结果显示超临界CO2萃取法得到的麻疯树籽油品质优于螺旋压榨法。     

超临界CO_2流体萃取石榴籽油工艺条件的研究

以石榴籽为原料,对超临界CO2流体萃取石榴籽油的工艺条件进行了研究。通过单因素试验,研究了萃取压力、萃取温度和萃取时间对石榴籽油得率的影响。在单因素试验的基础上,通过正交试验确定了超临界CO2流体萃取石榴籽油的最佳工艺条件。结果表明,超临界CO2流体萃取石榴籽油最佳工艺条件为:萃取压力40 MPa,萃取温度55℃,萃取时间80 min,分离釜Ⅰ温度60℃,压力10 MPa,分离釜Ⅱ温度35℃,压力6 MPa。在最佳工艺条件下,石榴籽油得率为18.6%。     

螺旋藻油的超临界提取及GC/MS分析

研究了超临界CO2流体萃取螺旋藻油的条件,着重研究了萃取压力、温度、萃取时间和CO2流量对油脂萃取率的影响,优化了萃取工艺条件即萃取压力25MPa,温度40℃,时间2h,CO2流量30kg/h,并利用GC/MS分析了最佳条件下萃取的螺旋藻油成分组成.     

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.