Effect of Modified Casein to Whey Protein Ratio on Dispersion Stability, Protein Quality and Body Composition in Rats

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 casein to whey protein (CW) ratio affected the extent of protein aggregation, and heated CW-2:8 showed a significantly increased larger particle (>100 μm) 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.

Whey Proteins-Fortified Milk with Adjusted Casein to Whey Proteins Ratio Improved Muscle Strength and Endurance Exercise Capacity without Lean Mass Accretion in Rats

“…Nevertheless, the CW ratio did not show a significant difference in growth performance among the milk-administered groups. Similarly, in our previous study, we reported that different CW compositions of the experimental diet did not alter body weight and weight gain [ 20 ]. Additionally, Yajima et al demonstrated that body weight gain did not change with CW ratio in rats [ 29 ].…”

“…The increased viscosity or firmness of the coagulant was observed as the ratios changed from CW0:10 to CW8:2 [ 41 ]. Our previous study’s findings also showed that CW2:8 significantly increased true digestibility compared to CW10:0, CW8:2, and CW5:5 in rats [ 20 ]. In contrast to previous studies, we observed no significant difference in the true digestibility among all groups.…”

“…Having integrated the above information, it appears that blending casein and whey proteins may create a synergistic benefit by complementing each other. Previous studies investigated the effects of the addition of casein or whey proteins for the physicochemical properties of food [ 17 , 18 , 19 ]; however, few studies have investigated the effect of adjusting the ratio of casein to whey proteins (CW) in milk on the protein quality and biological activities [ 20 , 21 , 22 ]. Our previous study demonstrated that CW5:5, the adjusted protein composition in the diet, improved protein quality in rats compared to other ratios [ 20 ].…”

“…Previous studies investigated the effects of the addition of casein or whey proteins for the physicochemical properties of food [ 17 , 18 , 19 ]; however, few studies have investigated the effect of adjusting the ratio of casein to whey proteins (CW) in milk on the protein quality and biological activities [ 20 , 21 , 22 ]. Our previous study demonstrated that CW5:5, the adjusted protein composition in the diet, improved protein quality in rats compared to other ratios [ 20 ]. Additionally, CW4:6 reduced the allergenicity compared to CW8:2, which is the conventional ratio of cow’s milk [ 21 ].…”

Whey protein‐derived peptides improve blood profile and enhance muscular endurance in mice

“…Milk protein comprises 80% casein protein, and 20% whey protein and has been shown to effectively enhance gastrointestinal activity, function and immunity (Maldonado Galdeano et al 2011;Pezeshki et al 2015). Whey protein is more effective than casein protein in reducing food intake, weight and fat gain, and improving glucose tolerance (Jeong et al 2021). The whey protein comprises several bioactive fractions, including glycomacropeptide, β-lactoglobulin, αlactalbumin and lactoferrin, which decrease body weight and fat content (Pezeshki et al 2015).…”