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目的 降低乳清分离蛋白中的致敏蛋白含量, 制备低致敏性乳制品。方法 利用碱性蛋白酶水解乳清分离蛋白, 研究酶添加量、初始pH、酶解时间以及温度对乳清分离蛋白水解度的影响。在单因素的实验基础上, 采用Box-Behnken实验设计方法进行四因素三水平的响应面优化实验。结果 在P<0.05的水平下, 4个因素对乳清分离蛋白的水解度都有显著影响。最优的水解工艺为: 酶添加量6.4%、初始pH 11、酶解时间4 h、温度60 ℃。乳清分离蛋白在此条件下水解后, 水解度达到21.11%。酶解液的十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis, SDS-PAGE)分析显示, 经过这一优化工艺水解, 10 kDa以上的蛋白基本全部被降解。高效液相色谱法(high performance liquid chromatography, HPLC)分析酶解产物的多肽及蛋白质分子量分布, 结果显示酶解产物的分子量大都分布在3.5 kDa及以下。采用间接竞争酶联免疫吸附法原理测定2种标志性致敏蛋白(β-乳球蛋白和α-乳白蛋白)的残余抗原性, 发现2种致敏蛋白的残余抗原性也有不同程度的降低。结论 通过碱性蛋白酶水解后, 乳清分离蛋白中具有致敏性的大分子蛋白转变为小分子的肽类, 从而降低了致敏性。 相似文献
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酶解对乳清蛋白抗原性影响的研究 总被引:6,自引:0,他引:6
研究了酶解对乳清蛋白抗原性的影响。选择了7种常见蛋白酶在同一水解模式下水解乳清蛋白,用竞争ELISA法测定水解物的残留抗原性,从而间接测定其过敏性变化。结果表明,酶解能有效降低乳蛋白抗原性,但水解物仍能与特异抗体反应,保留一部分抗原性。不同酶对乳清蛋白过敏原的影响不同,酶的特异性对乳清蛋白水解物的抗原性有较大的影响,碱性蛋白酶降低乳蛋白抗原性的效果最佳,对抗β-乳球蛋白(β-LG)和抗α-乳白蛋白(α-LA)抗体的抗原性分别降低了50.02%和99.72%。 相似文献
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采用蛋白酶诱导乳清浓缩蛋白(WPC)成胶,对影响凝胶性质的乳清浓缩蛋白质量浓度、酶与底物比(E/S)、pH 值、温度以及钙离子浓度分别进行研究。结果表明:乳清蛋白质量浓度、反应pH 值、温度和钙离子浓度均会不同程度地影响乳清蛋白凝胶的质构性质和保水性,且当乳清蛋白质量浓度为10g/100mL,E/S 为0.5%pH 值为7.0,酶解温度为50℃,钙离子浓度为2.5mmol/L 时制得的乳清蛋白凝胶具有类似于脂肪的质地和口感,具有很好的模拟脂肪特性。透射电镜分析表明此凝胶为一种结构较为松散的颗粒聚集状凝胶。 相似文献
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为降低水酶法提取大豆油过程所产乳状液的稳定性,得到较高的游离油回收率,研究了α-淀粉酶、纤维素酶、Alcalase碱性蛋白酶、7L中性蛋白酶的破乳效果;通过破乳率、Zeta电位、粘度、粒径分布和平均粒径指标,分别考察了Alcalase碱性蛋白酶和7L中性蛋白酶对乳状液稳定性的影响。结果显示,在所选酶中Alcalase碱性蛋白酶、7L中性蛋白酶破乳效果最好,相同水解条件下,Alcalase碱性蛋白酶的破乳率高于7L中性蛋白酶。2%的7L中性蛋白酶酶解60 min时破乳率达100%,而在相同酶解时间内,1% Alcalase碱性蛋白酶即可实现100%破乳。经Alcalase碱性蛋白酶和7L中性蛋白酶水解后,乳状液的粘度变低,电位电势减弱,油滴发生聚集,导致乳状液稳定性下降。随Alcalase和7L蛋白酶浓度和酶解时间的增加,相应地,乳状液的粘度进一步降低,破乳率上升。 相似文献
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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. 相似文献
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Sophie Guillot Laurence Peytavi Sylvie Bureau Renaud Boulanger Jean-Paul Lepoutre Jean Crouzet Sabine Schorr-Galindo 《Food chemistry》2006
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. 相似文献
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Jesus Simal-Gandara Miguel Sarria-Vidal Arjen Koorevaar Rinus Rijk 《Food Additives & Contaminants》2000,17(8):703-711
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. 相似文献
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Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates 总被引:2,自引:0,他引:2
A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel. 相似文献
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Anne Theobald Catherine Simoneau Philippe Hannaert Patrizia Roncari Anna Roncari Thomas Rudolph Elke Anklam 《Food Additives & Contaminants》2000,17(10):881-887
The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study. 相似文献
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M. S. Garcí a-Falc n J. Simal-G ndara S. T. Carril-Gonz lez-Barros 《Food Additives & Contaminants》2000,17(12):957-964
A simple, rapid and inexpensive method has been developed for the determination of benzo[a 相似文献
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H. J. Van Den Top A. Boenke P. A. Burdaspal J. Bustos H. P. Van Egmond T. Legarda A. Mesego A. Mourino W. E. Paulsch C. Salgado 《Food Additives & Contaminants》2001,18(9):810-824
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. 相似文献
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A. Boenke 《Food Additives & Contaminants》2001,18(12):1135-1140
The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here. 相似文献
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《肉类研究》2014,(2)
<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 相似文献