酶法制取鲮鱼皮胶原蛋白寡肽工艺的研究

本文以水解度为指标,在2709碱性蛋白酶、537酸性蛋白酶、A.S.1.398中性蛋白酶三种蛋白酶中确定2709碱性蛋白酶为最佳水解用酶.在单因素试验的基础上利用通过响应面法优化2709碱性蛋白酶水解鲮鱼皮制取胶原蛋白寡肽的最佳工艺条件为:底物浓度120g/L,pH值10.0,酶与底物比2200U/g,温度50℃,水解时间2h,最大水解度为28.23%.     

复合酶法水解蟹肉的研究

研究碱性蛋白酶和复合风味蛋白酶水解螃蟹肉的工艺条件。探讨了时间、酶用量、初始pH值、固液比浓度和温度对螃蟹肉水解效果的影响。在单因素试验的基础上,通过多因素响应面设计实验,获得最适水解工艺条件为时间4h、碱性蛋白酶先水解1h后再加入复合风味蛋白酶共同作用、初始pH值为8.3,固液比浓度为1∶2.5,温度60℃,碱性蛋白酶用量为1.2×10-3AU/g(蛋白质)、复合风味蛋白酶用量1.5LAPU/g,此时蛋白质的水解率为22.8%,TCA可溶性氮增长率含量为40.47%。     

酶法水解乳清蛋白工艺研究

以乳清蛋白为原料,选择碱性蛋白酶水解乳清蛋白.通过四因素三水平正交试验设计方法对碱性蛋白酶水解乳清蛋白的工艺条件[酶-底浓度比(E/S),pH,水解温度,水解时间]进行优化,确定了碱性蛋白酶酶解乳清蛋白的最佳水解条件为酶-底浓度比0.05,pH8.0,反应温度60℃,水解200min,此条件下水解度为21.92％.各因素对水解度的影响主次顺序为酶-底浓度比(E/S)＞水解温度＞水解时间＞pH.     

液压压榨澳洲坚果粕酶解制备多肽工艺优化

以液压压榨澳洲坚果粕为原料,分析了其常规营养成分含量与氨基酸组成。采用碱性蛋白酶与中性蛋白酶催化酶解澳洲坚果粕蛋白制备多肽。以水解度为指标,利用单因素试验与正交试验考察了各因素对澳洲坚果粕蛋白水解度的影响。结果表明：液压压榨澳洲坚果粕中含有32.25%的蛋白质,17 种氨基酸,含量为25.05%。碱性蛋白酶各因素对澳洲坚果粕蛋白水解度影响的主次顺序为：酶解时间＞酶解温度＞加酶量＞酶解pH值＞底物质量浓度,最佳工艺条件为：酶解温度60 ℃、酶解时间3.5 h、底物质量浓度110 g/L、酶解pH 8.0、加酶量2 400 U/g,在此条件下水解度达到了22.83%。中性蛋白酶各因素影响水解度的主次顺序为：加酶量＞酶解时间＞底物质量浓度＞酶解温度＞酶解pH值,最佳工艺条件为酶解温度55 ℃、酶解时间3.5 h、底物质量浓度100 g/L、酶解pH 7.0、加酶量3 200 U/g,水解度达到了22.78%。碱性蛋白酶与中性蛋白酶各因素对澳洲坚果粕蛋白水解度的影响均达到了极显著水平（P＜0.01）。在最佳工艺条件下,碱性蛋白酶酶解液压压榨澳洲坚果粕制备多肽的效果优于中性蛋白酶。     

饲用鱼蛋白肽生产工艺研究

以水解度作为指标,研究了碱性蛋白酶水解鱼粉废水中鱼蛋白制备饲用蛋白肽的工艺条件.考察了酶用量、酶解温度、pH值、酶解时间和底物质量分数等因素对蛋白质水解度的影响.通过正交试验对工艺条件进行优化,确定了最适工艺条件为:底物质量分数16％,振荡速度130 r/min,碱性蛋白酶用量为鱼粉废水中蛋白质的1.0％,酶解温度为60℃,pH值为8.5,反应时间为4.5h.在此最佳条件下得到具有浓郁鱼腥香味,水解度为25.06％的饲用鱼蛋白肽产品.     

蛋白酶水解豆渣制备大豆肽的研究

以大豆豆渣为原料,分别采用木瓜蛋白酶、碱性蛋白酶、中性蛋白酶对大豆豆渣进行水解制备大豆肽.研究了3种蛋白酶在不同温度、pH值、水解时间、酶浓度下水解大豆豆渣的最适酶反应条件,以及水解产物对酸豆乳发酵的影响.结果得出,实验豆渣蛋白质含量为10.4 g/(100 g);木瓜蛋白酶的最适水解条件是底物质量分数5％,酶浓度20 000 U/g,水解温度为50℃,pH7,水解6h,最大水解度可达87.31％;碱性蛋白酶的最适水解条件是底物质量分数5％,酶浓度15 000 U/g,水解温度为55℃,pH9,水解3h,最大水解度可达91.23％;中性蛋白酶的最适水解条件是底物质量分数5％,酶浓度15 000 U/g,水解温度为45℃,pH7,水解8h后达到最大水解度,最大水解度可达81.42％.     

鸡全蛋蛋白质酶水解工艺的研究

就Alcalase碱性内切蛋白酶水解鸡全蛋蛋白质最佳工艺条件进行了研究,得出了最佳的水解工艺条件,即:pH=7.0、水解温度60℃、底物浓度7%、酶用量(E/S)8%条件下水解5h,其水解率达42.79%。     

双酶水解虾粉的研究

为了提高虾加工下脚料的利用价值,用Alcalase碱性蛋白酶和Flavourzyme复合风味蛋白酶同步水解虾粉,分析了水解温度、水解时间、起始pH值、酶用量（E/S）和底物浓度等对水解度的影响,确定的最佳酶解条件为：底物浓度为9.0%、Alcalase碱性蛋白酶和Flavourzyme风味蛋白酶的添加量均为1.0%、水解温度为55℃、起始pH值为6.5和酶水解时间为8h,水解度为22.1%。     

碱性蛋白酶水解蓝圆鲹条件的优化

以水解度为优化的指标,利用单因素试验考察酶解温度、pH值、反应时间等因素对鱼蛋白水解的影响,利用中心组合试验方法优化酶的添加量和蛋白质浓度.结果表明:碱性蛋白酶水解蓝圆鲹的最佳条件为每克蛋白加酶量4 320U、蛋白质浓度1.57%、水解温度55℃、反应体系pH值7.5、酶解时间6 h,在此条件下,水解体系的氨基酸态氮含量达1.30 g/L,水解度为51.88%,总氮回收率为97.07%,挥发性盐基氮含量为0.030 g/L,氨基酸态氮、水解度和总氮回收率的RSD值均小于2%.     

玉米多肽制备工艺的优化

采用碱性蛋白酶水解玉米蛋白为玉米多肽,对影响碱性蛋白酶水解玉米蛋白的主要因素进行了探讨,通过单因素分析和正交试验筛选出最佳工艺参数。研究结果表明：酶水解玉米蛋白的最佳条件为：pH值9.0、底物浓度[S]5.0%、酶底物浓度比（E/S）3.0%、水解温度50℃、水解时间1h。     

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