水酶法提取玉米胚芽油研究

在水酶法制取玉米胚芽的工艺中，纤维素酶和中温－α淀粉酶的复合作用能显著提高玉米胚芽油的收率。其最适参数为：料液比为１∶５；蒸汽预处理时间为２５分钟，酶的加酶量为０．８％（纤维素酶和淀粉酶的配比为５∶３），反应时间为６小时。     

水酶法提取玉米胚芽油的优化工艺研究

对水酶法提取玉米胚芽油的最适酶进行了确定,以纤维素酶和中温α-淀粉酶复合使用效果最好.在纤维素酶和中温α-淀粉酶复配比例为1:1条件下,用响应面分析法对水酶法提取玉米胚芽油的工艺进行了优化,以玉米胚芽油的得率为响应值,确定了酶水解的最适参数:液固比5.1:1,蒸汽处理19.6 min,酶的添加量1.037%(V/W),酶解时间6 h.在此条件下的提油率为89.75%.     

玉米胚芽综合利用的加工工艺研究

对玉米胚芽蛋白及玉米胚芽油的制取进行了初步研究。影响玉米胚芽蛋白提取率的因素包括固液比、浸提温度和浸提时间 ,结果表明 ,固液比 1∶10 ,浸提温度 45℃ ,浸提时间 6 0min时有较好的抽提率。在水酶法制取玉米胚芽的工艺中 ,纤维素酶的作用能显著提高玉米胚芽油的收率。其最适参数为 :料液比 1∶3,蒸汽预处理时间 2 0min ,添加量 1%,反应pH值 5 5 ,温度为 5 5℃以及反应时间 6h。     

不同酶处理对小麦胚芽油提取率的影响

研究不同酶处理对小麦胚芽油提取率的影响,确定最佳水酶法提取小麦胚芽油工艺。选用纤维素酶、半纤维酶、酸性蛋白酶、淀粉酶、果胶酶作为提取酶,对小麦胚芽进行酶解,研究了不同酶处理对提油率的影响。单一酶处理试验中,分别用纤维素酶和酸性蛋白酶处理的提油率较高;复合酶处理试验中,酸性蛋白酶和纤维素酶组合处理的提油率最高;且复合酶处理比单一酶处理的提油率高。经过正交试验得出小麦胚芽油水酶法最优提取工艺为:复合酶(酸性蛋白酶∶纤维素酶=5∶1),酶解pH=5,酶解温度45℃。经验证试验小麦胚芽提油率可达到65.53%。试验提取的小麦胚芽油不饱和脂肪酸含量高达82%以上,营养品质较好。     

水酶法提取玉米胚芽油工艺优化

采用水酶法提取玉米胚芽油并对工艺进行优化。通过单因素试验和正交试验,确定水酶法提取的最佳工艺条件：液料比5:1(mL/g)、复合酶用量2.5%、酶解时间7h、pH6.0,复合酶种类为纤维素酶和α- 淀粉酶,添加质量比为4:3。在此条件下,玉米胚芽油提取率为89%。气相色谱对玉米胚芽油进行分析结果表明：油酸、亚油酸含量分别为43.46% 及40.22%。     

玉米胚芽分步酶解法提油工艺的研究

研究了分步酶解法提取玉米胚芽油工艺的实验室条件,确定最佳提取参数为料液比1∶0.77,玉米胚芽颗粒大小为105目,纤维素酶添加量6870 U/g,蛋白酶添加量1648 U/g,纤维素酶酶解时间7.4 h,蛋白酶酶解时间2.8 h。在最佳条件下,清油提取率可达75.38%。     

玉米胚芽分步酶解法提油工艺研究

研究低水分分步酶解提取玉米胚芽油工艺实验条件,确定最佳提取参数：料液比为1：0．78,玉米胚芽颗粒大小为105目,纤维素酶添加量为6,936 u/g,蛋白酶添加量为1,670 u/g,纤维素酶酶解时间为4.3小时,蛋白酶酶解时间为2．8小时,总提油率可达98.3%。     

分步酶解法提取玉米胚芽油工艺的研究

本文研究了低水分分步酶解提取玉米胚芽油工艺的实验室条件。确定了最佳提取参数为料液比为1：0．5,玉米胚芽颗粒大小为120目,纤维素酶添加量为5000U／g,蛋白酶添加量为500U／g,纤维素酶酶解时间为6h,蛋白酶酶解时间为3h。总提油率可达到98．3％。     

采用酶法从豆渣中制备2种膳食纤维

豆渣经物理方法脱脂后 ,采用高温淀粉酶和纤维素酶进行降解 ,从中同时提取得到 2种膳食纤维 (水溶性纤维和水不溶性纤维 )。高温淀粉酶的酶解条件为酶浓度 0 2 %,温度 1 0 0℃ ,时间 1 2 0min ;纤维素酶的酶解条件为酶浓度 0 7%,温度 35℃ ,时间 6h。分析表明 ,水溶性纤维中含蛋白质 33 5 7%,水不溶性纤维中含蛋白 2 6 3%。酶解获得的 2种膳食纤维经动物实验证明 ,在调节糖代谢和降低血浆甘油三酯方面都有一定的生理活性。     

双酶法提取玉米胚芽油工艺研究

利用双酶法提取玉米胚芽油,研究了原料预处理方式、酶制剂种类、添加量、酶解温度、pH、时间等因素对油脂浸出率的影响.试验结果表明较适工艺参数为:颗粒度60目筛下物,湿热处理10 min,酶制剂种类为纤维素酶+中性蛋白酶复合酶制剂(w/w=4∶3),添加量1.0%,酶解温度50℃,pH 4.0,时间4 h,固液比1∶7,油脂浸出率可达81.4%.     

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