蛋白质乳化作用与置换吸附探讨

乳化剂是食品加工中广泛应用的添加剂之一。蛋白质作为一种天然乳化剂,具有较大的市场潜力,受到广泛关注。酪蛋白、乳清蛋白、鸡蛋黄等作为常用的蛋白质乳化剂已大量应用于食品中,获得广泛认同。探讨了蛋白质作为乳化剂的乳化作用机理,介绍了复合蛋白质乳化体系中蛋白质的置换吸附(displacement adsorption)过程、发生的条件以及相关研究进展,为复合蛋白质乳化剂的选择和开发提供了理论依据。     

食品乳化剂的工业应用

<正>近年来,工业化生产食品已经获得了显著的普及和发展,食品乳化剂在提高食品的质量、使用性能和生产效率等方面已发挥了极其重要的作用。食品乳化剂作为食品添加剂的作用,首先是油脂与水的乳化分散,其     

从国外公司开发上市的几个新产品看乳化剂今后发展的动向

众所周知，食品用乳化剂是食品加工中，如乳制品和冰淇淋之类产品，可以使原料组成的水和油分从原先不相互熔转变为充分熔合成一体，形成如牛乳一样的乳状液。乳化剂也由此成名。其实从界面活性作用考虑，乳化剂不光有乳化作用，而且还包含了使物料分散、渗透、洗净、发泡、消泡和脱模等多种作用。这就是乳化剂在食品加工中被广泛使用的原因。除此以外，乳化剂对淀粉类制品还有防止老化和调整油脂结晶等特殊功效。     

乳化剂应如何正确添加到食品中

应用乳化剂的介晶理论,乳化剂在添加到食品中前,首先将其制成凝胶或水合物,然后再添加到面包、蛋糕等烘培食品中。试验结果表明,将乳化剂制成凝胶或水合物后再添加到食品中,则可以大大提高乳化剂的作用效果。     

芦荟爱美丽

在食品加工中，如冰淇淋等产品，应用乳化剂可以使原料组分中的水和油从不相溶转变为充分融合，形成牛乳样的液体状。从界面活性作用考虑，乳化剂不光有乳化的作用还包含了使物料分散、渗透、洗净、发泡、消泡和脱模等多种作用和功效。此外，乳化剂对淀粉类制品还有防止老化和调整油脂结晶等特殊功效。这就是乳化剂在食品加工中被广泛使用的原因。     

食品乳化剂的介晶理论及实际应用

乳化剂是食品工业中使用最广泛、最重要的一类食品添加剂 ,除具有典型的表面活性作用外 ,还能与食品中碳水化合物、蛋白质、脂类发生特殊的相互作用 ,而起到多种功效。它具有安全可靠 ,使用方便的特点 ,能起到乳化、保鲜、品质改良、起泡等多种功能。根据乳化剂的介晶理论 ,乳化剂具有多晶性 ,即α 晶型、β 初级晶型和 β 三种晶型。乳化剂在使用前只有处于α 晶型结构 ,应用到面包、蛋糕等食品中才能充分发挥作用效果     

乳化剂在粮油食品中作用机理的研究(下)——(食品抗老化保鲜、面团改良作用)

四、乳化剂的面团改良作用机理(一)问题的提出乳化剂加入食品中,例如面包、糕点,能增强面筋蛋白质强度,改善面团物理性能,特别是增大了食品的体积,提高了食品内部组织的疏松度,改善了品质.为了更好地了解乳化剂在食品中的品质改良作用机理,我们有必要介绍一下面包等发酵类产品的特点.面粉和水搅拌后,蛋白质吸水形成了面筋,构成面筋的主要成分是麦胶蛋白和麦谷蛋     

食品乳化剂的发展趋势

1食品乳化剂的现状食品乳化剂属于表面活性剂,由亲水和疏水(亲油)部分组成。由于具有亲水和亲油的两亲特性,能降低油与水的表面张力,能使油与水“互溶”。它具有乳化、润湿、渗透、发泡、消泡、分散、增溶、润滑等作用。乳化剂在食品加工中有多种功效,是最重要的食品添加剂,广泛用于面包、糕点、饼干、人造奶油、冰淇淋、饮料、乳制品、巧克力等食品。乳化剂能促进油水相溶,渗入淀粉结构的内部,促进内部交联,防止淀粉老化,起到提高食品质量、延长食品保质期、改善食品风味、增加经济效益等作用。世界上食品乳化剂约65种,FAO/WHO制订标准…     

蛋白质——果胶复合物的乳化特性及其在含油食品中的应用

根据其对奶油、蛋黄酱和其它含油脂食品制备的重要性,很好地研究了蛋白质的乳化特性,蛋白质的乳化作用不总是充分获得很好质量的稳定性。在食品工业中,化学稳定剂的使用不是合适的,最好的方法之一是改善乳化剂的质量,生产高营养值的乳化剂,使用蛋白质—多糖复合物作为乳化剂。改变复合物中蛋白质——多糖的比例,即聚合的种类,将改变食品的质量和营养价值。试验了四种非商品化的蛋白制剂作为乳化剂,并添加果胶改善其乳化特性,这使得产生新的低油含量和高营养价值的食品。     

大豆分离蛋白/可溶性大豆多糖作为生物活性物质包埋载体的研究进展

目前大豆分离蛋白(soy protein isolate,SPI)和可溶性大豆多糖(soluble soy polysaccharide,SSPS)均已实现工业化生产,在食品领域中得到了广泛的应用.作为生物大分子物质,以SPI和SSPS为壁材来包埋疏水性小分子生物活性物质受到众多学者的关注.以姜黄素为代表的疏水性小分子...     

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