Hartley方法优化菠萝皮渣多酚化合物提取工艺

在单因素试验基础上,采用SAS9.2中的响应曲面分析-Hartley方法对菠萝皮渣中的多酚类化合物提取工艺进行优化,建立提取温度、提取时间、乙醇体积分数和液料比4个因素与总多酚得率(Y)之间的编码水平回归模型,并得出各因素对菠萝皮渣总多酚得率的影响顺序为提取温度>提取时间>液料比>乙醇体积分数。在提取温度48.4℃、提取时间73.6min、乙醇体积分数41.6%、液料比46.8:1(mL/g)的条件下,菠萝皮渣总多酚得率最高,可达7.77mg/g,与理论值7.80mg/g基本吻合。响应面法所得的优化提取条件工艺参数可靠,可用于菠萝皮渣中多酚产品的开发。     

石榴籽中多酚的醇提取工艺优化

运用正交试验对石榴籽多酚的乙醇提取条件进行了优化。研究了提取温度、提取时间、乙醇体积分数和料液比四因素对石榴籽多酚提取效果的影响。结果表明石榴籽多酚的最佳提取条件:提取温度60℃,提取时间120min,乙醇浓度60%,料液比1∶20。在最佳提取条件下的石榴籽多酚得率为2.431mg/g干物质。     

薄荷多酚的提取及其在卷烟嘴棒中的应用研究

为了更好的开发利用薄荷,研究使用超声波辅助萃取技术从薄荷中提取薄荷多酚,通过单因素试验考察乙醇体积分数、超声温度、超声时间、超声功率、固液比对薄荷多酚得率的影响,并结合响应面分析法对提取工艺进行了优化,然后将制备的薄荷多酚施加于卷烟滤棒中,研究其对卷烟感官品质的影响。研究结果表明超声波辅助乙醇提取薄荷多酚的最佳工艺参数为:乙醇体积分数60%,超声温度74.14℃、超声时间28.05 min、超声功率165.57W、固液比1∶36.35(g/m L),此工艺条件下理论得率为1.24%,实际得率为1.29%;薄荷多酚添加于卷烟滤棒中具有提高生津感、缓解刺激、掩盖杂气的功效。     

响应面法优化燕麦多酚提取工艺

以燕麦为实验材料,在单因素的基础上,以乙醇体积分数、温度、料液比、提取时间等因素为自变量,多酚得率为响应值,通过Box-Behnken实验设计的方法,研究各自变量及其交互作用对多酚得率的影响,采用响应面分析法,模拟得到二次多项式回归方程的预测模型,确定燕麦总多酚的最佳提取工艺参数为:乙醇体积分数60%,温度39℃,液料比14∶1,提取时间59min。验证实验结果显示,此条件下燕麦粗多酚提取得率为4.59%。     

石榴皮总多酚的微波辅助提取工艺及抗氧化活性研究

利用响应面分析法优化石榴皮总多酚的微波辅助提取工艺,以总多酚得率为指标,通过单因素试验及响应面分析,研究了乙醇体积分数、提取时间、提取功率和液固比4个主要因素对石榴皮总多酚得率的影响。采用BoxBenhnken中心组合设计和响应面分析法,建立了回归方程的预测模型,确定最佳提取条件为乙醇体积分数58%、提取时间98 s、提取功率235 W、液固比49∶1(m L/g)。此条件下总多酚得率为(23.26±0.15)%。试验结果与模型预测值基本相符。用红外光谱对总多酚提取物进行了表征。石榴皮总多酚对DPPH自由基的半清除质量浓度为0.28 mg/m L,具有较强的抗氧化作用。     

白背三七类黄酮提取工艺条件的优化

采用乙醇提取法研究白背三七类黄酮化合物的提取工艺条件。通过单因素试验和正交试验,考察了乙醇体积分数、料液比、提取温度、提取时间等四个因素对类黄酮得率的影响;优化了白背三七类黄酮的提取工艺条件。结果表明,各因素对类黄酮得率的影响大小依次为乙醇体积分数＞提取温度＞料液比＞提取时间,白背三七类黄酮提取的最优工艺条件为：乙醇体积分数85%,料液比1∶25（g∶mL）,提取时间120 min,提取温度60 ℃。在此最佳提取工艺条件下,类黄酮平均得率为3.81%。     

石榴皮中多酚的醇提取工艺优化

为确定最优的提取条件,以提高石榴多酚的得率,采用四因素二次回归正交旋转组合设计试验,研究了提取温度、提取时间、料液比和乙醇体积分数对石榴多酚得率的影响,建立了各因子与石榴多酚得率关系的数学回归模型;最后确定了最佳的提取条件为:提取温度为70℃,液料比25:1,提取时间1.5h,乙醇体积分数50%,石榴皮多酚得率为16.28%。     

湿法粉碎辅助溶剂提取葡萄皮渣中多酚的研究

通过正交试验,优化分析确定湿法粉碎辅助溶剂提取葡多酚的最佳工艺条件。通过单因素试验研究了粉碎时间、固液比、乙醇体积分数、提取温度和时间对葡多酚产量的影响,利用正交试验优化得出各因素的最佳条件:粉碎时间30 s、料液比1∶20(m/v)、乙醇体积分数60%、提取温度60℃、提取时间1.5 h,在该条件下葡多酚产量可达到64.26 mg GAE/g,IC_(50)(DPPH)值为59.08 mg/L。     

响应曲面法优化微波辅助提取苹果渣多酚工艺研究

为从苹果渣中提取具有生理活性的多酚物质,在单因素试验的基础上,采用响应曲面法优化微波辅助提取苹果多酚的工艺,建立该工艺的二次多项数学模型,研究微波功率、提取时间、乙醇体积分数和料液比4个因素及其交互作用对提取工艺的影响.试验结果表明,对苹果多酚得率的影响次序是:微波功率>料液比>提取时间>乙醇体积分数;微波辅助提取苹果渣多酚的最佳工艺条件是:微波功率650W、提取时间53 s、乙醇体积分数60%、料液比1:20(g/mL),多酚得率迭61.8286 mg/100 g干果渣.     

柿果多酚提取工艺优化

采用单因素试验设计,研究乙醇体积分数、料液比、提取时间和提取温度4个因素对柿果总酚及缩合多酚超声提取效果的影响,并采用正交试验设计对提取工艺进行优化。结果表明影响因素对提取效率影响顺序为：乙醇体积分数＞料液比＞提取时间＞提取温度。最佳提取条件为：乙醇体积分数90%、料液比1:40(g/mL)、时间30min、提取温度40℃,在此条件下进行验证实验,总酚提取率为2.061%。     

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.