响应面法优化生物酶法提取滇红茶多糖工艺技术研究

以云南滇红茶为试验材料，采用响应面法优化生物酶法探讨其茶多糖提取工艺。在复合酶添加量、复合酶种类、复合酶比值、酶解时间、酶解温度、料液比各因素的单因素试验基础上，以茶多糖提取率为响应值，通过Box-Behnken中心组合优化法优化提取工艺参数，选取提取时间、复合酶添加量和料液比构建三因素三水平响应面优化试验。结果表明，滇红茶多糖的最佳工艺条件：复合酶种类为果胶酶和纤维素酶（质量比2∶1），复合酶添加量为0.90%（以底物质量计算），提取时间为3.0 h，提取温度45℃，料液比为1∶20(g/mL)。该条件下茶多糖提取率为4.22%±0.17%，与模型预测相符，可用于复合酶法提取滇红茶多糖。     

超声波辅助水酶法提取啤酒花精油的研究

对啤酒花精油超声波辅助水酶法提取工艺进行了研究,通过单因素试验,运用Plackett-Burman试验设计、最陡爬坡试验结合Box-Behnken设计对提取工艺进行响应曲面优化。评价了复合酶量(木瓜蛋白酶∶纤维素酶∶果胶酶=1∶1∶1,质量比)、料液比、酶解温度、酶解时间、酶解pH、超声波功率、超声波时间7个因素对啤酒花精油提取率的影响。用中心组合设计及响应面分析法确定最优条件为:复合酶添加量3.0%、酶解温度50℃、酶解时间2.5 h、酶解pH5,实际啤酒花精油提取率为5.27%。     

水酶法提取胡麻籽油的工艺及性质研究

以内蒙古胡麻籽为原料,采用水酶法提取胡麻籽油。在单因素试验的基础上,采用响应面分析优化工艺条件,并分析了胡麻籽油的品质。试验得到胡麻籽油的最佳提取工艺条件为料液比1∶14.34(g/mL)、pH 4.9、酶解温度48.9℃、酶解时间3 h、加酶量2.16%,在此条件下胡麻籽油的提取率为64.0%。经测定,水酶法提取的胡麻籽油气味、滋味纯正,水分及挥发物含量为0.132%,酸价(KOH)为1.21 mg/g。     

果胶酶酶法提取亚麻籽油工艺条件优化北大核心CSCD

为提高亚麻籽油提取率,以亚麻籽为原料,采用果胶酶酶法提取亚麻籽油。采用单因素实验探讨了料液比、酶解温度、酶解时间对亚麻籽油提取率的影响,在此基础上采用响应面法对果胶酶酶法提取亚麻籽油的工艺条件进行了优化。结果表明,果胶酶酶法提取亚麻籽油的最佳工艺条件为料液比1∶5、果胶酶添加量3%、酶解温度56℃、酶解时间6 h,在此条件下亚麻籽油提取率为85.64%。采用果胶酶可以有效提取亚麻籽油。     

湿法超微粉碎结合水酶法提取辣木籽油及其氧化稳定性分析

以辣木籽为原料,经湿法超微粉碎预处理后再经过低温烘干制成辣木籽粉,通过水酶法提取辣木籽油。利用单因素实验研究料液比、pH、酶添加量、酶解时间、酶解温度对辣木籽油提取率的影响,在此基础上采用正交实验确定水酶法提取辣木籽油的最佳工艺条件;并以辣木籽油过氧化值为评价指标,考察光照、温度和抗氧化剂对辣木籽油氧化稳定性的影响。结果表明,辣木籽油最佳提取条件为:以中性蛋白酶和复合蛋白酶按1∶1组成的复合酶为酶解用酶,料液比1∶6,pH 5. 0,复合酶添加量6%,酶解温度50℃,酶解时间8 h。在最佳提取条件下,辣木籽油提取率为85. 23%±0. 72%。光照及高温均能使辣木籽油的过氧化值升高,其中光照比温度对辣木籽油过氧化值的影响更大。因此,贮藏辣木籽油时,应尽量放置低温、避光处。另外,添加抗氧化剂BHT也能有效提高辣木籽油的氧化稳定性。     

复合酶协同高压热水浸提法提取香菇多糖的研究

研究了采用复合酶协同高压热水浸提法从香菇中提取活性多糖的最适条件。通过单因素试验和正交试验,探讨了料液比、酶添加量、酶解时间、酶解温度和酶解p H对香菇多糖提取率的影响,并以香菇多糖提取率为评价指标,优化提取工艺。试验结果表明,复合酶协同高压热水浸提法提取香菇多糖的最适条件为:料液比为1∶40(g/m L),酶添加量为1%,反应70 min,酶解温度为60℃,p H为3。     

水酶法提取胡麻籽油工艺条件的研究

采用水酶法提取胡麻籽油并对其工艺条件进行了详细研究。在单因素实验的基础上,通过正交实验得出了最佳工艺条件,即20 g研碎油料,加酶量为0.10 g,酶解温度50℃,酶解时间1h,最适pH 5.4,料液比1∶10,浸提温度90℃,浸提时间9 h。另外,水酶法提取胡麻籽油的提油率比水浸法提取胡麻籽油的提油率高24.55%。     

黑皮鸡枞菌多糖提取工艺及抗氧化活性研究

以黑皮鸡枞菌子实体为试验材料,研究复合酶法提取黑皮鸡枞菌多糖的最佳工艺条件,并测定黑皮鸡枞菌多糖的抗氧化活性。分别考察复合酶比例、液料比、复合酶添加量、酶解温度、酶解pH、酶解时间对多糖提取率的影响,根据单因素试验结果,设计响应面试验优化提取工艺。通过测定DPPH自由基清除率、羟基自由基清除率评价黑皮鸡枞菌多糖的抗氧化活性。黑皮鸡枞菌多糖提取条件确定为：以纤维素酶∶果胶酶∶木瓜蛋白酶为4∶3∶3制备复合酶,复合酶添加量3.0%,液料比47∶1 (mL/g),酶解温度54℃,酶解pH 7.5,酶解时间73 min,此时,多糖提取率达18.75%。黑皮鸡枞菌多糖浓度为4.0 mg/mL时,DPPH自由基清除率、羟基自由基清除率分别达93.44%、47.58%,表现出较强的抗氧化活性。复合酶提取黑皮鸡枞菌多糖的方法具有较高的多糖提取率及抗氧化活性。该方法可以为黑皮鸡枞菌多糖的开发和利用提供理论依据和新的思路。     

响应面法优化大黄鱼内脏鱼油提取工艺

为了优化大黄鱼内脏鱼油的提取工艺条件。以鱼油提取率为指标,考察了不同酶解时间、酶添加量、酶解温度、料液比和pH值对大黄鱼内脏鱼油提取率的影响,采用响应面法优化大黄鱼内脏提取鱼油的最佳工艺条件。结果表明:酶解时间、酶添加量和酶解温度对大黄鱼内脏鱼油提取率的影响显著,最佳工艺条件为:酶解时间2 h、酶添加量3000 U/g、酶解温度50℃、料液比1:6 g/mL、pH值8,在此条件下,鱼油的提取率为(63.8±0.57)%。     

超声波协同复合酶法提取香菇多糖的工艺优化

优化超声波协同复合酶法提取香菇中多糖成分的工艺。以香菇多糖提取率为评价指标,采用单因素试验和正交试验,确定最佳提取工艺参数。结果表明,超声波提取优化工艺条件为:料液比1∶15(g/mL),超声温度70℃,超声时间12 min。在此最佳超声提取条件下香菇多糖提取率为8.97%。在超声波优化的基础上,进行复合酶处理,最佳酶解工艺参数为:酶解时间50 min,复合酶(木瓜蛋白酶∶纤维素酶∶果胶酶=1∶1∶1,质量比)添加量3%,酶解温度60℃,酶解pH5.5,在此优化条件下香菇多糖提取率为12.46%。     

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