The Nutritive Value of the Protein of Varieties of Legumes and the Effect of Methionine Supplementation

Abstract
Since none of four varieties of lima beans (Phaseolus lunatus), five varieties of snap beans (Phaseolus vulgaris) and nine varieties of edible peas (Pisum sativum), when fed as the sole source of a 10% protein level, promoted more than slight growth in the white rat, it is concluded that there are no significant differences in the nutritive value of their unsupplemented proteins. The responses were markedly less than those of soybeans (Soja Max.) and chick peas (Cicer arientinum) fed under the same conditions. The addition of 0.1% methionine to the basal diet caused an immediate growth response and increase in the gain per gram of protein consumed for all of the varieties of lima beans, snap beans and peas, as well as for soybeans and chick peas, and with this supplementation differences in the nutritive value of the protein of these varieties become apparent. When the level of methionine was raised to 0.6%, there was a further growth response and gain per gram of protein consumed except in the case of three varieties of peas for which losses occurred. Of the eighteen varieties of lima beans, snap beans and peas tested, only the protein of the King of the Garden variety of lima beans, when supplemented with methionine, promoted average daily gains and gains per gram of protein consumed of the same order as those obtained with soybeans supplemented with methionine and with dried whole beef. The nutritive value of the protein of chick peas (also called “garbanza,” “gram” and “ceci”) is almost as high as that of the soybeans. When three varieties of snap beans, picked green, were fed in the cooked and dried form as the sole source of a 10% protein level, they failed to promote growth and the addition of 0.6% methionine resulted in only very slight gains for two of the varieties. The methionine content of the legumes, on the oven-dried basis, ranging from 0.29 to 0.85%, did not have a direct relationship to nutritive value of the proteins. The methionine of soybeans and chick peas is more readily available to the rat than that present in the varieties of lima beans, snap beans and peas studied.