响应面法优化番茄渣中番茄红素的提取工艺

为充分利用番茄渣,利用有机溶剂浸提法提取了番茄渣中的番茄红素.首先研究了不同有机溶剂、液料比、温度、时间及pH值对浸提效果的影响.然后在单因素试验的基础上,采用三因素三水平的响应面分析法,根据回归分析确定了各因素与番茄红素提取收率之间的关系,并以吸光度值为响应值做响应面和等值线图.研究结果表明,番茄渣中番茄红素浸提的最佳工艺条件为:温度45.89 ℃、浸提时间6.25 h、pH值4.05.     

番茄下脚料番茄红素的提取

目的:研究番茄皮渣提取番茄红素的工艺和参数;方法:以石油醚:丙酮混合溶剂为浸出剂,研究提取时间、温度、固液比和pH设计4因素对提取的影响;结果:石油醚:丙酮(1∶1)混合溶剂为最佳的番茄红素浸出剂,最优提取工艺是:在中性条件下,以固液比1∶6,浸提时间为2h,浸提温度25℃;结论:实验结果为番茄皮渣提取番茄红素的工艺提供依据.     

番茄红素提取工艺的初步研究

实验主要对番茄渣中番茄红素的提取工艺和影响番茄红素提取的诸因素,如浸提液种类及料液比、浸提温度、时间、pH、浸取级数等进行了研究,并用正交实验确定了最佳的工艺条件.结果表明:选用丙酮:正己烷(3∶1)的混合溶剂作为浸提溶剂,漫提温度为35℃、pH值为6、漫提料液比为1∶3、漫提时间为4 h,漫提级数2次可取得最佳提取效果.     

番茄红素的提取分离及纯化的研究

目的:研究番茄红素的最佳提取工艺条件;方法:采用新鲜番茄果实为原料,研究不同溶剂、不同处理方法对番茄红素提取效果的影响,考察在不同的浸提温度、液料比、浸提时间、浸提次数这4个单因素条件下的浸提效果,并通过正交试验对番茄红素有机溶剂提取工艺进行优化.同时,经过加酶处理,研究其对浸提效果的影响;结果:以乙酸乙酯为浸提溶剂,结合搅拌处理获得了较好效果.各单因素试验结果显示的最佳值分别是:温度为55℃、液料比为3∶1、浸提时间为60min、浸提次数为3次.方差分析证明了浸提次数对番茄红素浸提效果影响达到了极显著水平(P＜0.01),纤维素酶处理可以明显地提高番茄红素的提取量;结论:试验结果可为天然番茄红素的提取分离及纯化提供技术参数.     

番茄红素提取工艺研究

研究了在不同因素下从番茄中提取番茄红素的效果，确定了最佳的浸提工艺条件为：用氯仿作为提取剂，提取温度为40℃，时间为5h，物料比为1：1（g：mL）时，浸提效果最好。     

超声波辅助提取番茄皮渣中番茄红素工艺的研究

以番茄皮渣为原料,采用超声波辅助提取工艺,研究提取溶剂、超声输出功率、提取料液比、提取总时间、超声辐射时间等因素对番茄红素提取效果的影响,通过响应面分析试验,确定超声波提取番茄皮渣中番茄红素的最佳工艺条件为:以乙酸乙酯为提取溶剂,95%乙醇按1∶3的比例对番茄皮渣进行处理,超声输出功率300W,料液比1∶6,提取总时间6 min,超声辐射时间3 s,三级提取,番茄红素提取率为98%以上.     

超声波法和微波法提取番茄红素的比较研究

以番茄皮渣为原料,比较了超声波、微波辅助提取2种不同的提取方法对番茄红素提取效果的影响。试验表明,微波辅助提取效果优于超声波辅助提取。微波提取番茄红素的最佳工艺条件:微波辐射功率400W,料液比1∶4,提取时间35s,提取2次,番茄红素提取率超过97%。     

超高压提取番茄渣中番茄红素的工艺优化

采用超高压技术提取番茄渣中番茄红素,在单因素试验基础上,采用正交试验法对番茄渣中番茄红素的超高压提取工艺进行优选,选用L9(34)进行正交试验,以番茄红素提取率为指标,考察超高压压力、保压时间、固液比、提取次数对番茄红素提取率的影响。得到的最佳工艺条件为超高压压力300MPa、保压时间5min、固液比1:10(g/mL)、提取次数3 次。番茄红素的提取率可达83.2%。超高压提取方法得率高、提取时间短,是一种提取番茄渣中番茄红素的适宜方法。     

响应曲面法优化番茄皮渣中番茄红素提取工艺的研究

采用乙酸乙酯从番茄皮渣中提取番茄红素并结合紫外分光光度法测定其含量。在单因素试验的基础上,利用响应曲面法优化了提取工艺,建立了浸提温度、浸提时间、液固比与提取率之间的数学模型,确定了番茄红素提取的最佳工艺条件,即以乙酸乙酯为浸提溶剂、浸提温度51℃、浸提时间2.3h、液固比8.9:1(V/g),在此最佳工艺条件下进行提取,番茄红素提取率为(28.74±0.05)%(n=3)。     

超声法辅助提取番茄渣中番茄红素的工艺研究

为充分利用番茄渣,研究了番茄渣中番茄红素的提取工艺。对影响番茄红素提取的各种因素,例如提取溶剂、料液比、提取时间、提取温度、pH值,超声波功率、提取次数等进行研究,并通过单因素实验和正交实验确定了最佳提取工艺条件。结果表明:当料液比为1:5(g:mL)、超声波输出功率为80W、提取时间为20min,提取温度为40℃、pH为6,番茄红素的提取率为62.52μg/g。     

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.     

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.     

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.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

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.