Nutritional evaluation of the protein of dried tomato pomace in the rat

Abstract

1. Nutritional evaluation of dried tomato pomace (DTP-20) as a source of protein was carried out using weanling rats. Comparisons were made with casein (CS), soya-bean meal (SOM-45) and the hydrocarbon-grown yeast Toprina (BP-T). The growth-promoting effects of the diets were evaluated over a period of 28 d of ad lib. feeding. 2. The unsupplemented DPT-20 had a protein efficiency ratio ( per ) of 2.18±0.13 and a net protein utilization ( npu ) of 0.55. The addition of dl methionine (5 g/kg) resulted in a per of 1.74±0.15 ( t 2.99, P < 0.01) and a npu of 0.40, while the addition of an amino acid mixture resulted in a per of 2.33±0.08 ( t 1.84, P < 0.1) and a npu of 0.70. 3. The reason for the decrease in growth and the reduced per and npu values recorded for the methionine-supplemented group of rats is not clear and it is discussed in connexion with an imbalance or a slight toxicity caused by the added amino acid.