从啤酒废酵母中提取甘露聚糖的工艺条件优化

以啤酒废酵母为原料提取甘露聚糖,通过对料液比、NaOH浓度、浸提时间、浸提温度进行单因素试验,并通过L9(34)正交试验优化提取工艺参数。结果表明:在料液比1∶17.5(m∶V),NaOH浓度2%,浸提时间1.0h,浸提温度90℃的最优条件下,甘露聚糖提取率为18.15%。     

正交试验优化葡萄酒泥酵母甘露聚糖提取工艺及其体外抗氧化作用

以诱导自溶的葡萄酒泥酵母细胞壁为试材,通过单因素试验及L9（34）正交试验优化酵母甘露聚糖提取工艺参数,并对其抗氧化活性进行测定。结果表明：在料液比1∶17.5（g/mL）、KOH质量分数3%、浸提时间1.5 h、浸提温度100 ℃的最优条件下,甘露聚糖提取率为18.37%;酵母甘露聚糖清除ABTS＋·、羟自由基、1,1-二苯基-2-三硝基苯肼自由基、超氧阴离子自由基和螯合Fe2＋的半数有效质量浓度（EC50）分别为1.156、1.550、9.724、2.387、0.669 mg/mL,具有良好的体外抗氧化活性。     

红法夫酵母甘露聚糖的提取

以红法夫酵母DMSO法提取虾青素后的剩余残渣为材料,经稀碱抽提以及费林试剂络合法提纯制取得到粉末状多糖,采用纸层析、红外光谱、高效液相、气相色谱分析最终分析确定该多糖为甘露聚糖,甘露聚糖得率4.65%,甘露糖与葡萄糖含量之比为4.3∶1;经理化测定其总糖占90.5%,甘露聚糖占78.6%,蛋白含量是4.42%。研究碱法制取红法夫酵母甘露聚糖的工艺条件,旨在为建立产业化可行的高效提取方法,拓宽红法夫酵母的应用领域提供参考。     

响应面法优化葡萄酒泥酵母甘露聚糖提取工艺条件

目的:优化热水浸提法提取葡萄酒泥酵母甘露聚糖工艺条件。方法:在单因素实验基础上,采用Box-Behnken实验设计,对影响热水浸提甘露聚糖的主要因素进行研究。结果:热水浸提法提取葡萄酒泥酵母甘露聚糖的最佳工艺条件为料液比1∶23(g/m L),浸提温度124℃,浸提时间5 h,浸提次数3次。在此条件下甘露聚糖得率为14.27%,提取效果最佳。结论:此方法绿色环保,成本低,适宜工业化生产。     

啤酒废酵母甘露聚糖的制备

本实验以啤酒废酵母为原料,研究了自溶法制备甘露聚糖的最佳工艺条件,并将优化后的自溶法和常用的酸碱法进行了比较,最后对最佳自溶条件在5L 发酵罐中进行了放大实验。结果表明：自溶24h 后,酵母残渣中的甘露聚糖含量达到最高值;制备啤酒废酵母细胞壁的最佳自溶条件为温度50℃、NaCl 2%、pH6,此条件下,酵母自溶残渣中甘露聚糖含量达到164.95mg/g,优于传统的酸法、碱法;自溶因素的重要性次序为：温度＞ NaCl浓度＞ pH 值。放大实验结果表明,最优自溶条件下甘露聚糖含量达到149.00mg/g。     

啤酒酵母泥胞壁多糖的提取

采用酶解法提取啤酒废酵母泥的酵母细胞壁多糖。采用正交试验加酶量、pH值、温度和酶解时间4个单因素对胞壁多糖提取率的影响。得出最佳提取条件为最适加酶量240IU／g，最适pH值4．0，最佳酶解时间2h，最佳酶解温度50℃，多糖得率可达60％。采用薄层层析法对胞壁多糖进行纯化，定性测得多糖的组分为甘露糖和葡萄糖。     

纤维素酶法提取花生粕中多糖的研究

以油脂加工企业热榨油后产生的花生粕为原料,研究花生多糖纤维素酶法提取工艺.在单因素试验的基础上,选定提取时间、提取温度、pH值和酶添加量等4因素实施中心组合试验设计,建立多糖提取率的二次回归方程,通过响应面分析得到优化组合条件.结果表明,在提取时间253rmin、提取温度43℃、pH值为5.9、酶添加量为0.3％的条件下,花生多糖的提取率达到极值为6.77％.为了检验模型预测的准确性,在优化的条件下进行提取试验,花生多糖提取率为6.47％.     

酶法提取芋艿蛋白质工艺

探讨木瓜蛋白酶对提取芋艿蛋白质的影响,获得最佳提取工艺。以木瓜蛋白酶为酶试剂提取芋艿蛋白质,以考马斯亮蓝法为蛋白质含量测定方法,采用单因素实验分别研究提取温度、酶量、pH值、提取时间对芋艿蛋白质提取率的影响,再通过正交试验对提取条件进行优化筛选,结果表明:提取温度是影响提取率的关键因素,其次分别是pH值、酶量,影响最小的因素是提取时间。此次研究得出的最佳工艺参数组合为:提取温度55℃,酶量3mg/g、pH值6.5、提取时间1h,在此条件下蛋白质提取率为10.20%。     

红芸豆淀粉酶法提取工艺的研究

以红芸豆为原料,通过在传统的湿磨工艺中添加碱性蛋白酶来提取红芸豆淀粉。试验以淀粉提取率和淀粉纯度为考量指标,对pH、提取温度和酶量对淀粉提取率和纯度影响进行考察。在单因素试验基础上,通过响应面分析法确定红芸豆淀粉酶法提取工艺,同时建立红芸豆淀粉提取的数学模型并验证其可靠性。以pH、提取温度和酶量为自变量,探讨这3个因素交互作用和最佳提取条件,并对其进行验证。试验结果表明:红芸豆淀粉酶法提取的最佳工艺条件:pH为8.45、温度为55℃、酶量为2.5 mg/g,在此条件下红芸豆淀粉的提取率为53.51%,纯度为99.44%。     

酶法提取红松种子蛋白工艺的研究

以红松种子为原料,利用中心组合试验设计对影响红松种子蛋白提取的因素水平进行了综合考察,优化了红松种子蛋白的提取工艺参数.采用单因素试验设计,考察了酶解pH、固液比、提取温度、提取时间、加酶量等因素对红松种子蛋白提取率的影响,通过对单因素试验结果的分析,筛选出影响蛋白质提取率的关键性因素.结合所筛选的关键因素应用响应面分析法研究了提取液pH、提取温度、提取时间、加酶量等关键因素对蛋白质提取率的影响,采用回归分析技术、拟合二次多项式试验模型,应用模糊数学处理优化,得到了最佳的综合因素水平,分别为:固液比1:25;pH 8.4;提取时间3.07 h;加酶量1.53%;提取温度54.16℃,在最佳条件下红松种子蛋白的提取率预测值为88.29%,实际测定值88.06%.结果表明采用响应面法来寻求酶法提取红松种子蛋白最佳条件是可行的.     

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.     

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.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the