复合L-氨基酸镁络合物合成的研究

以豆粕为原料,利用酶水解工艺制备复合L-氨基酸,将氯化镁与复合L-氨基酸螯合制备复合L-氨基酸镁。结果表明:豆粕酶水解最佳工艺条件为:固液比1∶25、pH8.5、加10%胰蛋白酶与8%植物蛋白酶、酶解时间4h,所得豆粕水解度为37.80%。复合氨基酸与氯化镁螯合的最佳工艺条件为:配位摩尔比3∶1、pH8.0、温度80℃、时间50min,此条件下螯合率为45.82%。经红外光谱分析,复合L-氨基酸与氯化镁之间存在螯合作用。     

木瓜蛋白酶水解黄粉虫蛋白质工艺条件的优化

目的优化木瓜蛋白酶水解黄粉虫蛋白质的工艺。方法以黄粉虫为原料,研究了酶用量、固液比、水解时间、水解温度及p H对氨基酸提取率的影响。结果最佳酶解条件为:酶用量2.5%,固液比1∶3,水解时间6 h,水解温度50℃,pH值6.75。结论得到了用木瓜蛋白酶水解黄粉虫蛋白质的最佳酶解工艺。     

木瓜蛋白酶酶解罗非鱼肉的工艺研究

采用木瓜蛋白酶对罗非鱼进行酶解,对不同液固比和酶浓度对水解罗非鱼的影响进行了研究。以总氨基态氮含量作为评价木瓜蛋白酶水解能力为指标,结果表明木瓜蛋白酶水解罗非鱼的最适加酶量为0.6%,水解最经济的固液比在1∶3左右。通过正交实验,得到木瓜蛋白酶单酶水解罗非鱼的最佳工艺条件为：酶浓度0.7%、水解温度60℃、水解时间3h、pH值6.0。     

木瓜蛋白酶水解黄粉虫蛋白质工艺条件的优化

目的优化木瓜蛋白酶水解黄粉虫蛋白质的工艺。方法以黄粉虫为原料,研究了酶用量、固液比、水解时间、水解温度及p H对氨基酸提取率的影响。结果最佳酶解条件为：酶用量2.5%,固液比1∶3,水解时间6 h,水解温度50℃,pH值6.75。结论得到了用木瓜蛋白酶水解黄粉虫蛋白质的最佳酶解工艺。     

酸性蛋白酶和纤维素酶联合水解蘑菇柄蛋白的研究

对蘑菇柄蛋白采用纤维素酶与酸性蛋白酶双酶联合水解处理,探索出最适工艺条件为先加纤维素酶,温度50℃,pH 4.5,固液比1∶9,酶用量9.0%,水解时间4 h;后加酸性蛋白酶:温度42℃,pH 3.2,酶用量9.0%,水解时间3 h。双酶联合水解后蘑菇蛋白水解率可达51%。     

木瓜蛋白酶酶解罗非鱼肉的工艺研究

采用木瓜蛋白酶对罗非鱼进行酶解,对不同液固比和酶浓度对水解罗非鱼的影响进行了研究。以总氨基态氮含量作为评价木瓜蛋白酶水解能力为指标,结果表明木瓜蛋白酶水解罗非鱼的最适加酶量为0.6%,水解最经济的固液比在1:3左右。通过正交实验,得到木瓜蛋白酶单酶水解罗非鱼的最佳工艺条件为:酶浓度0.7%、水解温度60℃、水解时间3h、pH值6.0。     

六种商品蛋白酶对鲢鱼蛋白水解效果比较研究

选用中性蛋白酶、碱性蛋白酶、胰蛋白酶、木瓜蛋白酶、动物蛋白水解酶、风味蛋白酶对鲢鱼蛋白进行酶解,以水解度为评价指标筛选出各种蛋白酶的最佳水解工艺条件,通过水解度和水解液综合风味选出水解效果最佳的酶.结果表明:风味蛋白酶、动物蛋白水解酶和木瓜蛋白酶为水解效果较好的酶,其水解度和水解液综合风味评分分别为:风味蛋白酶16.97％和8.4,动物蛋白水解酶23.38％和7.0,木瓜蛋白酶26.34％和5.6;三种酶的最佳水解条件分别为:风味蛋白酶酶用量为0.7％(W ∶ W),温度55℃,pH值8.0,液固比5 ∶ 1(W∶ V),时间4 h;动物蛋白水解酶酶用量为0.7％(W∶ W),温度55℃,pH值8.0,液固比5∶ 1(W ∶ V),时间4 h;木瓜蛋白酶酶用量为0.7％(W ∶ W),温度55℃,pH值7.0,液固比5 ∶ 1(W ∶ V),时间4h.     

脱皮双低菜籽粕制取复合氨基酸工艺研究

该文研究以脱皮双低菜籽粕为原料制备复合氨基酸,通过正交试验确定双低菜籽粕水解最佳工艺是:硫酸浓度15％,固液比(W/V)1∶6,水解时间10 hr;适宜脱色条件为:活性炭浓度2％、脱色温度90℃,脱色时间30 min;复合氨基酸得率为46.65％,纯度为55.91％。     

赤豆速溶饮品工艺探讨

以赤豆为原料,使用赤豆蛋白、纤维的简单分离技术,采用L（934）正交实验设计和二次旋转正交试验方法对影响赤豆中淀粉、蛋白质、纤维素水解的酶用量、底物浓度、水解温度、时间和pH等5项因素进行了试验。试验结果表明赤豆水解的最佳工艺条件为：淀粉酶加酶量0.5%（g酶/g赤豆）、水解温度100℃、水解时间3h、pH6.0、底物浓度1∶10（赤豆∶水）;蛋白酶加酶量0.1%（g酶/g蛋白质）、水解温度55℃、水解时间3h、pH5.5、底物浓度1∶8;复合纤维素酶加酶量0.46%（g酶/g纤维素）、水解温度46℃、水解时间17h、pH4.8、底物浓度1∶11。并以赤豆酶解产物为壁材,通过制备微胶囊技术制得全赤豆速溶饮品。     

利用含铬革屑制备液体冲施肥前驱体

本文采用氢氧化钾与碱性蛋白酶的新型反应体系,水解含铬革屑制备多肽水解液。以黏度、游离氨基量、氨基酸含量为实验指标,探索了酶与含铬革屑的百分比以及反应的时间、pH值等因素对反应体系革屑水解程度的影响。经一步碱水解,固液比1∶12.5,氢氧化钾用量32%,反应温度100℃,水解时间6 h。二步酶水解最佳条件为:酶用量5%,反应体系pH=10,反应4 h。     

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