毛细管电泳测量牛奶中的蛋白质.pdf

International Dairy Journal 9 (1999) 709}713
Correlation between i-casein variants and citrate ceolar cells of the udder and the concentration of 1976; Mariani, Losi, Morini & Castagnetti, 1979; Hans-
citrate in cow milk is about 90 fold of that in blood. The son & Pettersson, 1985). In contrast to this, in another
mean content of cow milk have been reported to be study the signi"cance of the correlation between citrate
} g L\ (Jenness, 1988). Citrate forms in milk salts content and the genetic variants of i-CN has not been
with calcium, magnesium and to a much lesser extent con"rmed (Remeuf, Cossin, Dervin, Lenoir & Tomas-
with sodium and potassium. About 7}10% of the total sone, 1991). Jakob (1993) also reported that there was no
citrate is associated with the casein micelle and its signi"cant di!erence between the i-CN phenotypes in
amount correlates with the Ca and Mg content (Holt, citrate content. The objective of the present study was to
1985). The binding of calcium and phosphate with casein investigate the citrate content in milk within half sibs of
may be enhanced by citrate ions (Visser, Schaier & van Brown Swiss ; Swiss Brown (BS ; SB) having inherited
Gorkom, 1979). Citrate also plays an important role in either the paternal haplotype B-A-B-A or B-A-B-B for