文章基本信息

标题：Proving the adulteration of ewe and goat cheeses with cow milk using the reference method of isoelectric focusing of γ-casein
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作者：Špoljarić, Jasminka ; Mikulec, Nataša ; Plavljanić, Dijana 等
期刊名称：Mljekarstvo
印刷版ISSN：0026-704X
电子版ISSN：1846-4025
出版年度：2013
卷号：63
期号：3
页码：115-121
语种：English
出版社：Hrvatska Mljekarska Udruga
摘要：The aim of this study was to introduce a reference method for the detection of cow milk in ewe and goat cheeses (EC 273/08) in order to protect manufacturers and consumers from adulterations and imitations, and to ensure alignment with the demands of domestic and EU markets. The method includes isolation of casein from cheese, isoelectric focusing of γ2- and γ3-casein originating from the hydrolysis of β-casein by plasmin, the detection and quantitative determination of γ-casein in cow, ewe and goat cheese by densitometry. Ewe or goat cheese products with a minimum of 1 % of cow milk are considered to be adulterated. For the quantitative determination of cow, ewe and goat milk in cheeses, standard mixtures of cow-ewe and cow-goat milk were made by adding 0; 0.5; 1; 2; 5; 10; 25; 50; 75 and 100 % (v/v) of cow milk. The quantification was performed by determining the peak area ratio of cow γ-casein in comparison to ewe/goat casein in prepared standard cheeses. The calibration curves were calculated based on the relation of the peak area ratio of cow γ-caseins (calculated as the percentage of total γ-caseins) in contrast to the relative content (%) of cow milk in the mixture. The method proved to be adequate for the detection of raw and heat-treated cow milk in fresh and ripened cheeses made from ewe or goat milk, or a mixture of ewe and goat milk.
关键词：cheese adulteration; isoelectric focusing (IEF); γ-casein; identification of milk types; ewe cheese; goat cheese