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

Abstract

I . 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. 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.Exploitation of agricultural by-products may make a substantial contribution towards better and more economic feeding of livestock. The nutritive potential of a number of available by-products is, however, inadequately known, a fact that discourages their efficient utilization in animal feeding. I n view of the shortage and the high prices of protein feeding-stuffs, some of these by-products could provide part of the protein needed by animals. In this respect it is clear that the country's resources in such products need to be fully developed and thoroughly evaluated nutritionally.Stahlin (1957) and Maymone & Tiberio (1959) have provided information on the nutritive value of the tomato-seed oilcake meal, a by-product obtained after the extraction of the oil from the tomato seed. The oilcake has a crude protein (CP) (nitrogen x 6-25) content ranging from 340 to 400 g/kg and its value as a protein supplement for broilers is considered to be good (Kalaisakis, Papadopoulos, Boufidis, Zacharioudakis & Gourakou, 1970). Dried tomato pomace is composed of tomato seeds and skin that remain after the expulsion of the juice. In the dry state, as fed, it provides approximately 950 g dry matter and 195-215 g CP/kg. The annual production of dried pomace in Greece is in the order of 3000 t, with good prospects for future increase.The purpose of this study was to assess, by a series of rat bioassay procedures, the protein quality of dried pomace, and obtain information regarding its nutritional value. The biological indices measured were the protein efficiency ratio (PER), the net protein utilization (NPU) and the growth response of the experimental animals to amino acid supplementation. The amino acid profile was compared to other protein supplements and the interpretation of the results obtained is discussed.https://www.cambridge.org/core/terms. https://doi

Comparison of the total protein, nitrogen, and amino acid composition of selected additives and ingredients used in composite meat products

“…than that of cereal grain derived proteins but lower than al., 1984) including potato waste meal and oat groats those of casein (Drouliscos, 1976) and whole-egg protein (FAO/WHO, 1965). Similar results were obtained from the essential amino acid indices and protein scores (data not shown) calculated from their amino acid composition (Table V) by the methods of Block and Mitchell (1946) and Oser (1951).…”

Nutritive Value of Tomato Pomace for Ruminants and Its Influence on In Vitro Methane Production

“…Tomato pomace replaced increased amounts of soybean meal in the experimental diets and rumen degradability of TP has been reported to be lower than that of soybean meal [2], which would indicate greater bypass protein in TP than in soybean meal. According to Drouliscos [44], the essential amino acids profile in TP protein is similar to that in soybean meal, but the low values of IDCP observed in our study indicate that about half of the protein reaching the small intestine may not be digested, whereas intestinal digestibility of soybean meal is greater than 90% [43]. In agreement with these results, Fondevila et al [2] and Yuangklang et al [40] reported a significant decrease in CP digestibility when replacing soybean meal by TP in the diet of lambs and beef cattle, respectively.…”

Protein Isolation from Tomato Seed Meal, Extraction Optimization

“…The potential of tomato seeds as a food source has been reported (Ammerman et al, 1963;Drouliskos, 1976;Kramer and Kwee, 1977a,b;Abdel-Rahman, 1982;Al-Wandawi et al, 1985;Lasztity et al, 1986;Rahma et al, 1986). The approximate composition of tomato seeds (dry basis) is: fat 1 l-20%, protein 15-22% and ash 3-7%.…”