大米多肽的生产及其在食品工业中的应用

本文概述了大米多肽的营养、功能等,介绍了国内外大米多肽的开发现状,大米多肽的工艺流程及在食品和医药方面的应用。     

大米多肽对冷冻面团发酵特性及馒头品质的影响

面团在冷冻过程中面筋结构以及酵母活力会被破坏,导致解冻之后发酵能力、馒头品质下降。该研究在冷冻面团中加入不同比例的大米多肽,测量其对冷冻面团发酵力、馒头质构、水分迁移以及比容这4个指标随冻融时间增加发生的变化。结果表明,大米多肽的添加可以显著提高馒头的比容和冷冻面团的发酵力。冻融4 d时,添加大米多肽的效果显现出来,到第8天更为显著,与空白对照组馒头相比,添加质量分数4%与8%大米多肽的馒头比容分别增加了0. 26 m L/g和0. 11 m L/g;面团发酵4 h后,体积分别增大了21. 07%和29. 32%。添加4%的大米多肽能够有效延缓冷冻馒头硬度、弹性、咀嚼性的下降以及黏聚性的上升。这些结果表明,冷冻面团中添加适量的大米多肽能抑制冻藏过程中水分迁移,有效减弱冻藏对面筋网络和酵母活力的破坏,从而提高冷冻面团制品的质构特性。     

大米蛋白的提取、特性及其应用的研究进展

大米是我国主要的粮食作物之一,资源丰富,其中大米蛋白不但营养价值高、易消化吸收,并且其水解多肽具有降血压、降胆固醇等功效,具有广阔的开发价值与利用前景。因此本文详细阐述了大米蛋白的碱提酸沉法和酶法等分离提取技术、空间组成等结构特性、起泡性和乳化性等功能特性以及大米蛋白的应用现状。以期为大米蛋白开发利用及相关精深产品加工研究提供参考依据,提高我国稻米资源的经济效益。     

大米源硒代多肽的制备及其抗氧化活性的研究

以富硒碎米为原料,研究了大米含硒蛋白提取条件、硒代多肽的酶法制备及其抗氧化活性.结果表明:NaOH浓度为0.07 mol/L、料液比1∶20 (m/V)、40℃下提取3h时可获得蛋白含量、硒含量分别为80.18％和0.583mg/kg的大米含硒蛋白.相对于木瓜蛋白酶和胃蛋白酶,胰蛋白酶水解大米含硒蛋白可获得具有更高抗氧化活性的多肽.在胰蛋白酶与底物浓度比1∶10,底物质量浓度60g/L,pH9.0,温度50℃的最佳酶解工艺条件下,所得大米硒代多肽的DPPH自由基清除率可达78.19％.因此,碱法提取是一种比较有效的大米含硒蛋白的提取方法,胰蛋白酶水解可获得较高抗氧化活性的大米硒代多肽.     

超声辅助酶解大米多肽的制备及其对酵母细胞增殖性影响

采用超声辅助酶解制备大米多肽,并研究其对酵母细胞增殖性的影响。在单因素试验基础上,对超声辅助酶解制备大米多肽进行工艺优化,确定最优超声辅助酶解工艺:超声功率密度51.8 W/L、超声温度50℃、超声时间15 min。在最优工艺条件下,大米多肽得率为70.57%。对酵母细胞培养增殖显示随着多肽浓度的增加而增强,当多肽浓度达到25 g/L后,酵母细胞增殖效果不再增强;另外超声辅助酶解的大米蛋白多肽作为氮源对酵母细胞培养增殖效果要好于常规酶解。     

大米多肽功能性质及制备方法的研究进展

综述国内外对大米多肽功能性质的研究进展,着重阐述其抗氧化活性和降血压活性,介绍国内外大米多肽的制备方法,指出大米多肽研究中需要解决的问题及应用前景.     

HPLC-MS/MS在活性多肽检测中的应用

多肽具有调节机体生理功能和为机体提供营养的双重功效，生物活性肽的分离和检测日益受到各国的关注。综述了近年来HPLC-MS／MS在某些活性多肽（化学合成多肽、阿片样肽、抗菌肽、磷酸肽）检测中的应用概况。     

多肽的功能活性与研究进展

科学研究发现生物体内存在多种具有生理活性的多肽物质,它们具有不同的结构和功能活性.人体摄入的蛋白质经酶水解后,主要以肽的形式被消化吸收.几乎所有细胞都受多肽调节,它具有调节机体生理功能和为机体提供营养的双重功效.人们已从包括人、植物、动物在内的各种生物体中分离出各类活性多肽,并且对多肽的性质、制备方法、分离纯化方法、鉴定技术、功能活性及应用等方面进行了大量的研究,并取得了一定的成效.本文介绍了近年来活性多肽的国内外研究现状,对多肽的多种功能活性进行了较全面地分析和介绍,概述了不同来源多肽的制备方法,展望了生物活性多肽在食品、医药、生物等领域的发展前景.     

基于超声预处理的大米降血压多肽的制备及其功能评价

采用酶法制备大米降血压肽。本文研究大米降血压肽制备中底物蛋白的超声预处理、酶解产物的超滤提取纯化、大米降血压肽的抗消化道酶降解及原发性高血压大鼠(SHR)一次性灌胃试验等。试验结果表明,最优超声预处理的参数为每升处理液施加超声功率250 W、超声时间10 min、工作间歇比1:2、循环转速30 r/s。经过超声预处理,酶解产物对ACE的抑制率由未经超声预处理的69.8%提高到92.8%。5 kDa为最佳的超滤提取纯化截流分子质量。经过超滤,滤液的IC50值随大米多肽分子质量的降低而降至1.71 mg/mL。大米降血压多肽具有良好的抗消化道酶降解能力,对SHR大鼠具有明显的降血压效果。     

多肽的功能及结构的研究进展

多肽是蛋白质水解产物,人体摄入的蛋白质经酶水解后,主要以肽的形式被消化吸收。机体内多肽几乎能调节全部细胞的生理功能并且可以为机体提供营养,它与蛋白质的氨基酸组成基本一致,而且多肽具有比蛋白质更稳定的加工性质和更易吸收的生理性质,这将会大大拓宽蛋白质的应用范围。本文介绍了近年来活性多肽的国内外研究现状,对多肽的多种功能活性和其作用机理进行了介绍,展望了生物活性多肽在食品、医药、生物等领域的发展前景。     

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