酶法水解大麦蛋白质新工艺的研究

采用传统的液化和糖化工艺,研究了复合型蛋白酶、木瓜蛋白酶和酸性蛋白酶对国产大麦蛋白质的水解情况,结果表明,选用以复合型蛋白酶为主,并添加少量酸性蛋白酶的效果较好,但á-氨基氮含量仍偏低.而采用一种新型的复合蛋白酶在液化前对蛋白质预水解,经液化、再添加蛋白酶进行糖化的新工艺,不仅提高了大麦汁中营养物质á-氨基氮含量,而且可溶性蛋白质还具有合理的隆丁区分.     

鱿鱼内脏蛋白质酶解工艺的研究

以氨基酸得率为主要指标,采用不同蛋白酶对鱿鱼内脏蛋白质进行了水解工艺研究。研究表明,中性蛋白酶、碱性蛋白酶、胰蛋白酶和木瓜蛋白酶具有较好的分解效果,氨基酸转化率可达到50%以上;胃蛋白酶分解效果较差。同时发现,木瓜蛋白酶和中性蛋白酶在一定条件下具有显著的协同水解效应。      

鱿鱼内脏蛋白质酶解工艺的研究

以氨基酸得率为主要指标,采用不同蛋白酶对鱿鱼内脏蛋白质进行了水解工艺研究。研究表明,中性蛋白酶、碱性蛋白酶、胰蛋白酶和木瓜蛋白酶具有较好的分解效果,氨基酸转化率可达到50%以上;胃蛋白酶分解效果较差。同时发现,木瓜蛋白酶和中性蛋白酶在一定条件下具有显著的协同水解效应。     

酶解海参肠口服液的研究

以海参加工废弃物--海参肠为原料,研究了不同的酶及酶组合水解工艺.其中,先采用A.S1398中性蛋白酶和木瓜蛋白酶(木瓜蛋白酶:A.S1398中性蛋白酶=1:1,酶活力比)双酶水解,再用Flavourzyme进行分段水解海参肠蛋白质,水解效果最佳,正交试验结果表明.Flavourzyme二阶段酶水解的最适工艺条件为酶添加量150U/g原料,时间1.5h,温度55℃,pH7.0,蛋白质水解度达88.08%;水解液再经过浓缩、调配、包装可制成营养丰富的保健品口服液.     

中性蛋白酶对无麦芽啤酒非生物稳定性的影响研究

直接采用大麦酿制啤酒,不经过制麦工艺,可有效地降低生产成本。该文主要通过对中性蛋白酶在糖化过程的应用以及对无麦芽啤酒的非生物稳定性的影响进行研究。实验结果表明,添加中性蛋白酶在一定程度上可降低高分子蛋白质的含量,有效地提高无麦芽啤酒的非生物稳定性,提高麦汁的质量,添加量在300mg/kg时效果最优。     

中性蛋白酶对啤酒酿造中麦汁质量的影响

随着啤酒工业的发展,酶制剂在啤酒酿造中的应用越来越广泛.文中主要对中性蛋白酶在糖化过程的应用及对麦汁的影响进行了研究.研究表明,中性蛋白酶添加量在250mg/(kg麦芽)以下,可以使麦汁中α-氨基酸态氮含量提高25%以上,高于250mg/(kg麦芽)反而不利于酶的作用.添加中性蛋白酶只能在一定程度上降低麦汁浊度和敏感蛋白含量,若要进一步提高麦汁稳定性,需要同时采取相应措施,控制麦汁中多酚物质的含量.     

菜籽蛋白酶解预处理条件研究

以脱脂菜籽粕制备的菜籽蛋白为主要原料,水解度为考察指标,探讨了蛋白酶的选择及湿热处理条件对蛋白质水解的影响。结果表明,碱性蛋白酶、酸性蛋白酶、中性蛋白酶和木瓜蛋白酶4种酶在其最适条件下水解菜籽蛋白能力顺序为碱性蛋白酶中性蛋白酶酸性蛋白酶木瓜蛋白酶。选择碱性蛋白酶进行菜籽蛋白水解,通过完全试验得出菜籽蛋白的湿热处理最佳工艺条件为:温度100℃,时间30min,此条件下,水解度可达到18.51%。     

挤压大米啤酒辅料的糖化工艺参数对麦汁碘值的影响

为了合理地确定挤压膨化大米啤酒辅料的糖化工艺参数,采用二次正交旋转组合试验方法,研究挤压蒸煮大米糖化工艺参数(65℃糖化时间、71℃糖化时间、耐高温α-淀粉酶添加量)对麦汁碘值的影响规律。研究结果表明,当65℃糖化时间为47 m in,71℃糖化时间为25 m in,α-淀粉酶添加量为1.75×10-3L时,挤压大米辅料糖化麦汁的碘值可达0.13,比传统大米辅料糖化麦汁的碘值减少了48%,另外,从麦汁各项指标的检测结果表明,挤压膨化大米做啤酒辅料的糖化工艺是可行的。     

复合酶水解猪血红蛋白制备富血红素多肽

以木瓜蛋白酶和AS1398中性蛋白酶组成的复合酶对猪血红蛋白进行水解,制备富血红素多肽,考察底物质量分数、加酶比例、水解pH值和水解温度等因素对水解率、蛋白质回收率、血红素含量等指标的影响。结果表明：底物质量分数是影响水解率和蛋白质回收率指标的最重要因素;pH值是影响血红素含量指标的最重要因素;复合酶水解猪血红蛋白制备富血红素多肽的最佳工艺条件为底物质量分数6%、pH8、水解温度55℃、加酶比例5:5(木瓜蛋白酶:中性蛋白酶)。在此工艺条件下,猪血红蛋白水解产物具有较高的蛋白质回收率和血红素含量。     

复合酶生产酪蛋白磷酸肽的工艺研究

实验以木瓜蛋白酶、胰蛋白酶、中性蛋白酶As1．398、碱性蛋白酶As2709 4种酶复合水解酪蛋白，生产酪蛋白磷酸肽。设计了木瓜蛋白酶 中性蛋白酶As1．398、木瓜蛋白酶 碱性蛋白酶As2709，胰蛋白酶 中性蛋白酶As1．398、胰蛋白酶 碱性蛋白酶As2709、木瓜蛋白酶 胰蛋白酶 中性蛋白酶As1.398和木瓜蛋白酶 胰蛋白酶 碱性蛋白酶As2709六种试验方案。通过比较水解度、酶促水解速率(酶活力)、得率和N／P比等工艺参数，探索合适的实验工艺条件。我们发现胰蛋白酶 中性蛋白酶As1．398这组的产品综合结果最佳。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press