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 less than 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 greater than 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.