The Effect of Feeding Tepary Bean (Phaseolus acutifolius) Proteinase Inhibitors on the Growth and Pancreas of Young Mice

Abstract

The effect of tepary proteinase inhibitor (TI) isolated from unheated tepary bean on the growth, nitrogen digestion and pancreatic hypertrophy of mice was assessed. The mice were fed a whole protein based diet containing either 0, 100, 200, 400 or 600 mg TI per 100 g of diet. Growth performance of mice fed whole egg or 100 mg TI/100 g diet was superior to that of mice fed 200, 400 and 600 TI mg/100 g diet. The growth inhibition of mice fed trypsin inhibitor above 200 mg TI/100 g diet was accompanied by a lower apparent digestibility of protein and lower food conversion efficiency. The pancreas weight relative to body weight of animals fed TI was significantly higher than that of animals fed whole egg. The results of the present study also indicate that TI is not responsible for the death of mice and rats fed raw tepary bean flour.