Article

Effect of modified casein to whey protein ratio on dispersion stability, protein quality and body composition in rats

Eun Woo Jeong1, Gyu Ri Park1, Jiyun Kim1, So-Yul Yun2, Jee-Young Imm2, Hyeon Gyu Lee1,*
Author Information & Copyright
1Department of Food and Nutrition, Hanyang University, Seoul 04763, Korea.
2Department of Foods and Nutrition, Kookmin University, Seoul 02707, Korea.
*Corresponding Author: Hyeon Gyu Lee, Department of Food and Nutrition, Hanyang University, Seoul 04763, Korea. E-mail: hyeonlee@hanyang.ac.kr.

© Copyright 2021 Korean Society for Food Science of Animal Resources. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Jul 09, 2021 ; Revised: Jul 29, 2021 ; Accepted: Aug 05, 2021

Published Online: Aug 05, 2021

Abstract

The present study was designed to investigate the effects of protein formula with different casein (C) to whey protein (W) ratios on dispersion stability, protein quality and body composition in rats. Modification of the CW ratio affected the extent of protein aggregation, and heated CW-2:8 showed a significantly increased larger particle (> 100 mm) size distribution. The largest protein aggregates were formed by whey protein self-aggregation. There were no significant differences in protein aggregation when the CW ratios changed from 10:0 to 5:5. Based on the protein quality assessment (CW-10:0, CW-8:2, CW-5:5, and CW-2:8) for four weeks, CW-10:0 showed a significantly higher feed intake (p < 0.05), but the high proportion of whey protein in the diet (CW-5:5 and CW-2:8) increased the feed efficiency ratio, protein efficiency ratio, and net protein ratio compared to other groups. Similarly, CW-2:8 showed greater true digestibility compared to other groups. No significant differences in fat mass and lean mass analyzed by dual-energy x-ray absorptiometry were observed. A significant difference was found in the bone mineral density between the CW-10:0 and CW-2:8 groups (p < 0.05), but no difference was observed among the other groups. Based on the results, CW-5:5 improved protein quality without causing protein instability problems in the dispersion.

Keywords: protein quality; milk protein; casein-to-whey protein ratio; particle size; bone mineral density