仙草胶提取方法比较研究

以广东增城派潭镇的仙草为原料,研究了碱液沸水提取仙草胶和碱液超声波辅助提取仙草胶的工艺,以及两种方法获得的仙草胶的特性黏度和多糖含量。碱液沸水法提取仙草胶的最佳工艺为:料液比为1:40,Na2CO3浓度为0.3%,浸提时间为90min,此条件下仙草胶得率达到36.80%。碱液超声波提取仙草胶的最佳工艺为:Na2CO3浓度为0.3%,料液比为1:40,超声功率为600W,提取时间为60min,此条件下仙草胶得率达到38.12%。碱液沸水法提取的仙草胶在25℃的特性粘度为99.608mL/g;碱液超声波提取的仙草胶在25℃的特性黏度为117.33mL/g。碱液沸水法提取的仙草胶中多糖含量为216.27mg/g;碱液超声波提取的仙草胶中多糖含量为309.08mg/g。     

银耳多糖对花生蛋白饮料稳定性的影响

从银耳子实体中提取得到银耳多糖浸提液,添加到花生蛋白饮料中,替代部分乳化剂和增稠剂,考察银耳多糖浸提液对花生蛋白饮料稳定性和质构特性的影响。结果表明:最佳条件为银耳多糖浸提液添加量10%、CMC添加量0.05%、黄原胶添加量0.1%、明胶添加量0.15%。由方差分析表可见,4个因素对花生蛋白饮料稳定性的影响顺序为银耳多糖添加量明胶添加量CMC添加量黄原胶添加量,并且银耳多糖浸提液添加量是影响花生蛋白饮料稳定性的显著性因素。在此最佳条件下做验证试验,得到花生蛋白饮料的稳定系数为98.4,稠度为193.56 g·s,黏度为6.587 g。测得市售花生蛋白饮料的稠度为198.65 g·s,黏度为6.587 g。添加银耳多糖提取液后,花生蛋白饮料与市售饮料的稠度和黏度接近。     

淫羊藿保健酒常温浸提工艺研究

研究了淫羊藿保健酒常温浸提的工艺条件,以淫羊藿总黄酮提取量为指标,在单因素试验的基础上,采用正交试验优化了淫羊藿保健酒常温浸提的工艺条件。结果表明,各因素对黄酮提取量影响的顺序为:乙醇浓度对黄酮提取量影响最大,料液比次之,浸提时间影响最小;最佳浸提工艺条件为:乙醇浓度为70%、料液比1∶40、浸提时间3h。在此条件下,淫羊藿总黄酮提取量为95.53±1.36mg/g。     

张氏马尾藻甘露醇的提取工艺

为优化张氏马尾藻甘露醇的提取工艺,研究分析浸提温度、料液比以及浸提时间对甘露醇提取效果的影响,通过单因素试验和正交试验得到提取甘露醇的最佳工艺参数：浸提温度100℃,料液比1∶100（g/mL）,浸提时间2.0 h。在此最佳工艺条件下,甘露醇提取量达5.636 mg/g。此外,对提取效果影响最大的因素是浸提温度,其次是料液比,影响最小的是浸提时间。     

杨梅渣膳食纤维提取工艺

以杨梅渣为原料,连续提取水溶性和不溶性膳食纤维,在单因素试验基础上,通过正交试验优化提取工艺条件。试验表明,适宜水溶性膳食纤维提取工艺为:以柠檬酸为浸提剂,料液比(g∶mL)1∶10,pH值2.0,90℃提取75 min,在此条件下提取率达58.62%。适宜的不溶性膳食纤维提取工艺为:料液比(g∶mL)1∶12.5,pH值2.5,60℃提取90 m in,在此条件下提取率达61.25%。所制备的不溶性膳食纤维持水力为570.6%、溶胀性为6.5 mL/g,功能特性良好、生理活性突出。     

超声波辅助提取菠萝皮多酚物质的研究

研究了超声波辅助提取菠萝多酚物质的工艺,对影响多酚浸提率的因素进行了单因素试验和正交试验,确定了最佳工艺条件为:乙醇浓度60%,浸提温度45℃,功率200W,浸提时间60min,液料比15.0∶1.0。在此条件下,浸提率可达18.48g/kg。     

苦瓜叶绿素提取工艺研究

以叶绿素提取量为指标,采用提取溶剂、浸提时间、液料比、温度的单因素试验和三因素三水平正交试验法优化了苦瓜叶绿素的提取工艺条件。结果表明,影响叶绿素提取的主次因素为浸提时间>液料比>温度,并且浸提时间、液料比、温度的影响都达到了极显著水平;叶绿素最佳提取工艺条件为:以丙酮、无水乙醇及水比例为4.5∶4.5∶1的混合溶液作提取溶剂,浸提时间为3h,液料比为10∶1,温度为60℃。在最佳工艺条件下,叶绿素提取量可达0.0317mg/g。     

黄精中水浸出物、多糖和皂苷综合提取工艺优化

以黄精为原料,采用单因素和正交试验研究浸提温度、料液比和时间对水浸出物、多糖和皂苷提取量的影响。单因素实验得出:影响较为显著的因素是浸提温度和料液比,时间对综合提取影响较小;正交试验分析得出:提取最佳工艺条件为浸提温度80℃,料液比1∶30(g∶mL),浸提时间3 h。在此优化条件下,水浸出物、多糖和皂苷提取量为67.92%,25.82%和6.64%。     

响应面分析法优化紫薯花青素提取工艺

以紫甘薯花青素为原料,采用柠檬酸水溶液为提取剂,分别研究提取剂浓度、浸提温度、浸提时间和料液比对花青素提取率的影响。在此基础上,采用3因素3水平响应面分析法,以吸光度为响应值,探讨浸提温度、浸提时间和料液比对紫薯花青素提取的影响并对提取工艺进行优化。紫薯花青素在波长为524nm处有最大吸收峰。单因素实验证明当柠檬酸浓度为5%、浸提温度为50℃、浸提时间为4h、料液比为1∶20g/mL时花青素提取率达到最大。响应面分析证明对花青素提取率影响大小的顺序为料液比、提取温度和提取时间。响应面分析法确定紫薯花青素最佳提取工艺参数为:提取温度46℃,提取时间6h,料液比1∶23g/mL,在此条件下花青素含量为159mg/100g。     

羊栖菜蛋白质提取及功能性研究

以羊栖菜为原料,考察提取工艺对其蛋白质得率的影响,并研究羊栖菜蛋白质的功能特性。通过单因素试验考察了液料比、碱质量分数、浸提温度和浸提时间等4个因素,根据Box-Benhnken试验设计和响应面分析法确定羊栖菜蛋白提取的最佳工艺条件。结果表明,羊栖菜蛋白的最佳提取条件为液料比21∶1（mL∶g）,碱质量分数2.5%,浸提温度57 ℃,浸提时间5 h。在此最佳工艺条件下,蛋白质得率为28.95%。羊栖菜蛋白的起泡性高达76.7%,优于大豆分离蛋白,而吸水性、吸油性、乳化能力、乳化稳定性、泡沫稳定性均不如大豆分离蛋白。     

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