五倍子中α-淀粉酶抑制因子的研究

采用甲醇粗提、索氏抽提及pH值梯度提取和聚酰胺柱层析等分离纯化法及酶反应动力学跟踪的方法对五倍子中的α-淀粉酶抑制因子进行系统研究。结果表明：乙醚、乙酸乙酯、丙酮-水(体积比1:1)、甲醇、石油醚组分和甲醇粗提物对α-淀粉酶的抑制率依次为：91.04%、90.38%、80.09%、66.48%、34.14%和23.96%。其中石油醚组分中的α-淀粉酶抑制因子是月桂酸、肉豆蔻酸和棕榈酸,其抑制率分别为34.34%、31.71%和31.01%,而乙醚组分中的抑制因子是鞣酸及没食子酸,其抑制率分别为66.7% 和21.3%。丙酮-水组分中的抑制因子较为复杂,经初步纯化和气质联用得知其为脂肪醇类并部分甲酯化。     

多酚化合物对黄嘌呤氧化酶抑制作用的研究进展

文章主要对近5年来多酚化合物抑制黄嘌呤氧化酶活性、抑制类型及相互作用研究进行了综述,并对其构效关系、结构修饰及金属配合物的开发与应用进行了展望,以期为多酚化合物作为降尿酸食品功能因子和药物的研发提供参考.     

绿豆中胰蛋白酶抑制子的纯化及部分性质的研究

本文研究将绿豆经过粉碎、过筛和正己烷脱脂后,采用（NH4）2SO4分级沉淀、DEAE-Sepharose CL-6B离子交换、Sephacryl S-200凝胶过滤等方法,对其中的胰蛋白酶抑制因子进行了分离纯化。然后研究了所纯化出的胰蛋白酶抑制子的pH和温度稳定性,实验结果表明：在20～100℃的范围和pH 2.2～10.2范围内,胰蛋白酶抑制因子性质较稳定。     

川芎嗪抑制肿瘤血管生成研究进展

川芎嗪(tetramethylpyrazine,TMP)是一种来源于植物和微生物发酵制品的生物碱类化合物,具有多种生物活性.本文综述了TMP的抑制肿瘤血管生成作用,包括抑制胃癌、肺癌、黑素瘤、大肠癌及其他恶性肿瘤的血管生成的研究情况,并探讨了其抑制机制.     

豆浆豆腐中胰蛋白酶抑制因子活性的研究

豆制品中含有丰富的营养物质,但其中的抗营养因子阻碍人体对营养物质的吸收。分别采用6种不同制浆工艺将5种原料豆进行豆浆、豆腐的制备,测定大豆和豆浆中蛋白含量以及豆浆、豆腐的产量,通过分析不同大豆品种及制浆工艺与豆制品产量及蛋白含量之间的关系,以产量为指标,研究不同大豆品种及其加工工艺对豆制品产量及蛋白含量的影响,选取高产量、高蛋白的豆制品。并采用紫外分光光度计法分别对原料豆、豆浆、豆腐等进行大豆胰蛋白酶抑制因子活性的检测,得出低大豆胰蛋白酶抑制因子活性的品种及加工豆制品的制浆工艺。结果表明,豆制品产量与蛋白含量成正比,不同大豆品种采用不同制浆工艺所制得的豆浆、豆腐中胰蛋白酶抑制因子活性具有显著性差异,为不同大豆品种适用性加工及工业化生产提供理论依据。     

血管紧张素转换酶抑制肽定量构效关系研究进展

在血压调节方面,血管紧张素转换酶（ACE）的活性是重要的影响因子。ACE抑制肽具有抑制ACE活性、降低血压等作用。其毒副作用小、安全性高。该文主要对血压调节机制、ACE抑制肽的降压机理、食源性ACE抑制肽的制备以及定量构效关系进行综述介绍,对指导ACE抑制肽的分子设计过程给予理论分析,有望开发出高活性的功能性食品及降血压药物。     

仙人掌多酚氧化酶的特性及抑制研究

本文研究了仙人掌中多酚氧化酶(PPO)的特性以及一些抑制剂对其活性的影响。结果表明:仙人掌中PPO的最适温度为50℃,最适pH有两个,分别为pH4.0和pH7.0,因而在仙人掌中的PPO存在同工酶。柠檬酸、抗坏血酸及EDTA对仙人掌PPO均有一定的抑制效果,抑制能力顺序为:柠檬酸>抗坏血酸>EDTA。对各种抑制剂的作用机理进行了探讨。EDTA主要是通过螯合PPO中的辅酶因子Cu2+而起作用,抗坏血酸螯合Cu2+的能力比EDTA弱,但抗坏血酸的还原能力较强,而柠檬酸则是通过降低pH和螯合作用抑制PPO。     

富硒辣木叶蛋白ACE抑制肽的酶解工艺优化及活性研究

以富硒辣木叶为原料提取富硒辣木叶蛋白,通过单因素实验和响应面优化富硒辣木叶蛋白血管紧张素转化酶(ACE)抑制肽的制备工艺,并对最优酶解物的ACE抑制活性、氨基酸组成和硒含量进行分析表征。结果表明,富硒辣木叶蛋白ACE抑制肽的最佳酶解条件为时间3 h,pH7.5、酶底比0.23%、底物浓度5.97%、温度39.2℃。该条件下制备的ACE抑制肽的ACE抑制活性较强(IC50=0.522 mg/mL),富含必需氨基酸(24.05%)和疏水性氨基酸(20.6%),其硒含量是辣木叶原料中硒含量的1.86倍。富硒辣木叶蛋白ACE抑制肽具有功能因子和天然食物的双重特性,此研究可为降血压药物及相关功能性食品的开发提供理论依据。     

酵母菌单菌固态发酵豆粕的研究

为了选育能够提高豆粕饲用品质的高效菌株,从12株酵母菌中筛选出一株优质酵母菌,以普通生豆粕为原料,通过L25(56)的正交试验,研究其对豆粕中胰蛋白酶抑制因子和小肽含量的影响,并对其发酵条件进行优化.结果表明,最优发酵条件为:6%的接种量,料水比为1:0.9,通气量为45 g/500 mL,在自然pH,30 ℃下发酵48 h;胰蛋白酶抑制因子含量显著下降,降解率达56.2%(42.53～18.63 mg/g),小肽含量提高了4.3倍(1.65%～8.7%).微生物发酵生豆粕能明显降解抗营养因子,从而改善其饲用品质.     

利用海洋生物蛋白制备ACE抑制肽的研究进展

血管紧张素转化酶(angiotensin convert enzyme,ACE)在血压调节方面起着重要作用,当其受到抑制时血压就会降低。本文综述了A C E抑制肽的降压原理、活性检测方法、分离提纯和海洋生物蛋白源A C E抑制肽的国内外最新研究进展,并对其应用前景进行了展望。     

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