Southern Peas and other Legume Seeds as a Source of Protein for the Growth of Rats

Abstract

Lima beans, pinto peas, English peas and Southern peas were compared with casein and with egg albumin as sources of protein for the growth of rats. The legumes were tested raw and after they had been autoclaved at 15 pounds pressure for 30 minutes. The heated Lima and pinto beans were superior to the raw beans as sources of protein; the raw Southern and English peas were slightly superior to the heated peas. The nutritive values of all the legumes were increased by the addition of 0.2% of methionine if the legume was heated before the methionine was added. Raw Lima beans were improved only slightly by the addition of methionine. On the other hand, raw English peas were improved markedly by supplementation with this amino acid, and the raw peas plus methionine were slightly superior to egg albumin when the heated legumes were supplemented with 0.2% of methionine. Southern peas were superior to casein but they had a lower value than egg albumin unless lysine and trptophane were fed in addition to methionine. In tests with Southern peas and with pinto beans 0.2% of methionine was required to give a maximum rate of growth. One-tenth % was not enough and 0.3% was no better than 0.2%. The Jackson Purple Hull, Long Pod Cream and Dwarf California Blackeye no. 5 varieties of Southern peas were compared with each other as sources of protein for growth. The tests were carried out in each case with heated peas and with and without the addition of methionine. The Jackson Purple Hull had a lower nutritive value in both tests than the other two varieties. These data suggest that protein availability may be lower in the Jackson Purple Hull, or that a smaller quantity of one or more of the essential amino acids may be present.