Ameliorative effects of boiling and methionine supplementation of raw soyabeans given to weanling rats

Abstract

in ameliorating the effects on anti-nutritional factors in raw soyabean were determined using Wistar rats. Six soyabean-based diets made up of three cooking durations of the seeds (uncooked, and boiled for 15 and 30 minutes) and two supplementation levels (none and supplementation with methionine) were compared. Boiling and methionine supplementation improved the nutritional value of the soyabeans as indicated by the relatively higher weights of liver, spleen, adrenal, the whole brain and brain parts of the rats. Boiling and methionine supplementation also eliminated hyperthyroidism. The relative thyroid weights of the rats on heated and/or supplemented soyabeans were 47-63 per cent of those of the rats on raw un-supplemented soyabeans. Boiling for 15 min. was sufficient to inactivate the trypsin inhibitors present in unheated soyabean. The nutritional improvement of the heated soyabeans by methionine was greater than that of the unheated soyabeans similarly supplemented.