期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1985
卷号：31
期号：1
页码：77-87
DOI：10.3177/jnsv.31.77
出版社：Center for Academic Publications Japan
摘要：Whey is a by-product of the manufacture of cheese from milk. The usual practice is to dispose of it, the usage of whey being not sufficiently developed, though it contains proteins of excellent quality such as β-lactoglobulin and α-lactalbumin. Interaction between κ-casein and whey protein was examined in order to form new food materials. Gelation of the heat-induced complex between κ-casein and α-lactalbumin is described in this paper. α-Lactalbumin was easily separated from whey protein by the gel filtration technique on a Toyopearl HW-50 column at pH 6.0. Heat treatment facilitated the hydrolysis of a mixture of κ-casein and α-lactalbumin by trypsin, α-chymotrypsin and pronase. Heat treatment at above 75°C and a protein level of over 5% were needed to form gel in 35mM phosphate buffer, pH 7.6, containing 0.4M NaCl. The temperature was in agreement with that at which α-lactalbumin denatured and formed the complex with κ-casein. Decrease of soluble protein concentration and increase of turbidity were induced with gelation. Gel was not formed when only κ-casein or α-lactalbumin was heated under the appropriate conditions. It was considered that a κ-casein-α-lactalbumin gel was formed from a complex of the two proteins by heat treatment. The breaking stress of κ-casein-α-lactalbumin gel was less than that of κ-casein-β-lactoglobulin gel. If the pH was reduced to 5.8 after complex formation by the two proteins, gel was formed at a low protein concentration compared with that with no alteration of pH.
关键词：κ-casein;α-lactalbumin;gelation;interaction;κ-casein-α-lactalbumin gel;separation of α-lactalbumin
