Objective
Although deficient in all indispensable amino acids, gelatin is used in protein-restricted diets. Food efficiency and protein quality of casein and gelatin mixtures in low protein diets in Wistar rats were investigated.
Methods
The rats were treated with protein-restricted diets (10.0 and 12.5%) containing casein (control diets), casein with gelatin mixtures (4:1 of protein content), and gelatin as sources of protein. The food conversion ratio, protein efficiency ratio, relative and corrected protein efficiency ratio, true protein digestibility, and hepatic parameters were estimated.
Results
After 28 days of the experiment, food efficiency of 10.0% casein/gelatin diet decreased when compared to that of 10.0% casein diet, and the protein efficiency ratio of the casein/gelatin mixtures (10.0%=2.41 and 12.5%=2.03) were lower than those of the casein (10.0%=2.90 and 12.5%=2.32). After 42 days of the experiment, the weight of the liver of the animals treated with 10.0 and 12.5% casein/gelatin diets, and the liver protein retention of the 12.5% casein/gelatin diet group of animals were lower than those of the control group.
Conclusion
Gelatin decreases food efficiency and high-quality protein bioavailability in protein-restricted diets.
Amino acids; Biological availability; Caseins; Gelatin; Proteins; Rats
