Abstract
It has been revealed that as much as 86% of soybean hulls in dried condition are carbohydrate fractions, which consist mainly of cellulose, acidic polysaccharides, galactomannan and xylan. In spite of their nutritional value of much a great percentage, however, the utilization of carbohydrate fractions by mammal body has scarcely been studied.
For the present study, hull powder and hull extract soluble in 1% sodium bicarbonate were prepared, and an experiment of the in vitro digestion on adult albino rats and seven kinds of enzymes sold on markets were carried out. The enzymes contained Cellulosin and Penase from Aspergillus nigar, Meiselase and. Sevelase from Trichoderma viride, Diastase, Pancreatin and Pepsin.
The enzyme activity hydrolyzing hulls was found to be very weak or even absent in the small intestines of albino rats. The hulls were degraded, it was concluded, to some extent by the micro-organisms in the cecum, because 92% of carbohydrate fractions had been degraded after incubation at 37°C for 24 hr.
The activity of the enzymes degrading hulls was observed, but of all the seven kinds of enzymes that produced from Asp. nigar was the most remarkable. The enzyme activity of Cellulosin was particularly high, which degraded about 60% of the carbohydrate. The twoenzymes from T. viride ranked next and the other three were found negative.
The hydrolysis of hulls by hydrochloric acid at pH values corresponding to acidity of human gastric juice was also studied. The degree of acid hydrolysis was small.
