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Influence of 2-mercaptoethanol on heat stability of concentrated whey-protein-free milk and formation of soluble casein

Published online by Cambridge University Press:  01 June 2009

Takayoshi Aoki  and
Yoshitaka Kako
Takayoshi Aoki
Affiliation:
Animal Products Processing Research Laboratory, Faculty of Agriculture, Kagoshima University, Kagoshima 890, Japan
Yoshitaka Kako
Affiliation:
Animal Products Processing Research Laboratory, Faculty of Agriculture, Kagoshima University, Kagoshima 890, Japan
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Summary

The heat coagulation time (HCT) of concentrated whey-protein-free (WPF) milk measured at 120 and 130 °C was reduced to by addition of 5–20 mM-2-mercaptoethanol (ME). However, although the amount of soluble casein formed on heating was doubled by addition of ME, the shape of the HCT–pH profile was affected only slightly. The proportion of κ-casein in the soluble casein from heated concentrated WPF milk containing ME was very high, though it was somewhat lower than that of the soluble casein from heated concentrated WPF milk containing no ME. No solubilization of colloidal Ca phosphate was observed in either unheated or heated concentrated WPF milk on addition of ME. These facts suggest that ME probably promotes the formation of soluble casein with release of κ-casein from micelles on heating, thus destabilizing the casein micelles.

Type
Original Articles
Information
Journal of Dairy Research , Volume 51 , Issue 3 , August 1984 , pp. 439 - 445
Copyright
Copyright © Proprietors of Journal of Dairy Research 1984

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References

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