响应面优化超声波-微波协同提取葡萄籽原花青素工艺研究

以衡水当地产葡萄籽为原料,利用超声波-微波协同提取葡萄籽原花青素。研究了乙醇体积分数、超声功率、超声时间、微波功率、微波时间、液料比对葡萄籽原花青素得率的影响。以单因素实验为基础,采用响应面法优化了超声波-微波协同提取葡萄籽原花青素工艺。结果表明,超声波-微波协同提取葡萄籽原花青素的最佳工艺条件为:乙醇体积分数50%,液料比21∶1,超声功率400 W,超声时间32 min,微波功率353 W,微波时间3.2 min。在最佳工艺条件下,原花青素得率为6.18%。     

响应面法优化超声辅助浸提葡萄籽原花青素

利用响应面优化法研究葡萄籽原花青素的超声辅助浸提工艺,以原花青素提取率为指标,在考察提取时间、提取温度、乙醇浓度、液料比对提取率影响的基础上,采用Box-Behnken中心组合法设计响应面优化试验方案,利用最小二乘回归分析建立预测模型,优化超声辅助浸提工艺参数。结果表明：各因素对葡萄籽原花青素提取率的影响大小依次为提取时间＞提取温度＞液料比＞乙醇浓度。响应面优化最佳工艺为室温（20℃）下超声处理20 min,水浴热回流提取时间1.0 h,提取温度70℃,乙醇浓度60%,液料比15∶1（mL/g）。在此条件下葡萄籽中原花青素提取率为4.68%,与模型预测值4.71%接近,相对标准偏差为1.22%,响应面法优化葡萄籽原花青素的提取工艺有良好的重现性,可为葡萄籽原花青素提取工业化提供参考。     

超声提取葡萄籽原花青素工艺的优化及其抗氧化活性研究

研究利用响应曲面法优化超声提取葡萄籽原花青素的工艺。在单因素实验基础上,采用中心组合设计响应面实验,考察了提取温度、液料比、乙醇浓度以及超声时间对原花青素提取率的影响,并建立回归模型。优化后的工艺:提取温度55℃,液料比20(mL/g),乙醇浓度65%,超声时间10min;在此条件下葡萄籽原花青素的提取率为2.482%,与回归模型预测值的相对偏差为0.36%。同时进行了提取物的抗氧化性检验,结果表明葡萄籽原花青素对超氧阴离子自由基具有较好的清除能力,且呈剂量相关性。     

葡萄籽中原花青素提取工艺

以发酵后葡萄籽为原料,研究微波、纤维素酶和超声波辅助提取葡萄籽中原花青素的工艺条件,对影响原花青素提取率的因素进行考察,通过正交试验确定葡萄籽中原花青素的最佳提取工艺。结果表明最佳方法为微波辅助提取,其最佳工艺条件：料液比1:25(g/mL)、乙醇体积分数80%、微波时间40s、微波功率115W,原花青素的提取率为10.70%。     

微波辅助提取葡萄籽原花青素的工艺研究

对微波辅助提取葡萄籽原花青素的工艺进行了研究,通过正交试验确定了微波辅助提取葡萄籽原花青素的最佳工艺条件,即微波功率为中低火、料液比为1：18、乙醇浓度为60％、微波作用时间50s,在最佳工艺条件下,原花青素的提取量为18．47mg／g。     

微波辅助水提葡萄籽原花青素的研究

对微波辅助从葡萄籽中提取原花青素的工艺进行了研究，在单因素和正交优化设计的实验基础上。确定了微波辅助提取葡萄籽原花青素的最佳工艺条件，即微波功率为中高火，料液比为1：18（g／mL），微波作用时间为70s，然后在沸水浴中浸提80min。微波辅助浸提法所得原花青素的提取率比单用传统水提法提高了约1倍。     

超声波提取葡萄籽原花青素的工艺优化及相关特性研究

本文旨在研究超声波提取葡萄籽原花青素的工艺条件,并对其进行优化。利用大孔树脂纯化粗提物,对纯化产物进行相关特性的研究。结果显示:当乙醇体积分数为65%,提取温度为25℃,超声功率为220W,超声时间为20min时,原花青素提取率可达到4.37%。经大孔树脂纯化,得到高纯度的原花青素。通过对葡萄籽原花青素的相关特性进行测量,结果表明葡萄籽原花青素具有良好的抑菌性和强氧化性。     

混合溶剂一步法提取葡萄籽油和原花青素的工艺研究

研究了混合溶剂一步法提取葡萄籽油和原花青素的工艺,试验结果显示最优工艺为料液比1：7、混合溶剂正己烷／95％乙醇比例4：6,提取温度65℃、提取时间3．5h,在此条件下葡萄籽油提取率为92．62％±3．74％,原花青素提取率为56．18％±4．12％。     

超声波辅助法提取葡萄籽中原花青素工艺的研究

提高酿酒后葡萄籽的综合利用率,探究在不同提取条件下超声波辅助法对葡萄籽中原花青素提取工艺的影响。在单因素试验的基础上,通过正交试验对提取工艺条件进行优化。结果表明,最佳提取工艺条件为乙醇体积分数70%,提取时间20 min,超声功率90 W,提取温度50 ℃,料液比1∶20（g∶mL）,在此最优条件下,葡萄籽中原花青素的提取率为3.98%。     

葡萄籽原花青素多级逆流提取工艺研究

目的:研究葡萄籽原花青素多级动态罐组式逆流提取工艺。方法采用正交试验设计,考察提取温度、提取级数和溶剂用量对葡萄籽原花青素提取率的影响,优选最佳工艺参数。结果:多级动态罐组式逆流提取葡萄籽原花青素的最佳工艺参数为:提取温度100℃,提取级数4级,溶剂用量3倍量,单提时间40 min;与单罐提取相比,该工艺的提取率略有提高,提取时间减少33%,单位药材的溶剂消耗量减少75%。结论:与传统工艺相比,多级动态罐组式逆流提取工艺能保证较高的葡萄籽原花青素提取率,缩短提取时间,大大节省提取溶剂,降低后续蒸发浓缩的能耗。     

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.