Journal article #J7739 of the Mississippi Aaricultural & Foreestry Experiment Station, Mississippi State, MS 39762.
k-Casein Heterogeneity and Mild Heating Effects on Susceptibility to Chymosin Action
Article first published online: 25 AUG 2006
Journal of Food Science
Volume 57, Issue 1, pages 49–54, January 1992
How to Cite
HAQUE, Z. U. and KHALIFA, M. Y. (1992), k-Casein Heterogeneity and Mild Heating Effects on Susceptibility to Chymosin Action. Journal of Food Science, 57: 49–54. doi: 10.1111/j.1365-2621.1992.tb05422.x
A Peace fellowship for author Khalifa and a research grant from the National Dairy Promotion and Resesrch Board awarded to author Haque are gratefully acknowledged. Collaboration regarding computer programming was with Professor Yoshiro Kamata as part of a collaborative research agreement between MSU and Miyagi University, Sendai, Japan.
- Issue published online: 25 AUG 2006
- Article first published online: 25 AUG 2006
- Ms received 4/19/91; revised 7/14/91; accepted 8/17/91.
Bovine SH-k-casein (k-C-pool) was fractionated into five components based on carbohydrate and sialic acid contents (k-C-P1 < k-C-P2 < k-C-P3 < k-C-P4 < k-C-P5) by ion-exchange chromatography (DEAE-cellulose). Chymosin susceptibility observed by monitoring changes in optical density during enzyme action, varied among the components. This was a reflection of the difference in self-association of the proteins in aqueous dispersion as determined by hydrophobic interaction chromatograph. There was an inverse relationship between surface hydrophobicity of the protein polymers (k-C-P2 >k-C-P3 >k-C-P4 > k-C-P5 > k-C-P4 > k-C-pool) and their susceptibility to chymosin at 37°C, pH 6.8 (k-C-pool >k-C-P1 >k-C-P5 > k-C-P4 > k-C-P3 > k-C-P2). Mild heating decreased susceptibility and affected flocculation of all except the highly glycosilated components k-C-P4 and k-C-P5 reflecting amphipathicity imparted thermostability.