醤油

Chemical changes in hydrolysing soy bean cake by concentrated hydrochloric acid at ordinary temperature have been studied in order to obtain a suitable material for the rapidbrewing of shoyu. Attempt has also been made to ferment the hydrolysate by the addition of shoyu-koji. The results are following. 1) Carbohydrate part of soy been cake is almost quantitatively hydrolysed. Furfurol which hinders the following fermentation forms- slightly during the hydrolysis. 2) The hydrolysate is rich in black colour, but poor in reddish colour characteristic to the best grade of shoyu. 3) The soy bean cake if hydro l ysed at 35°C liquefies very readily and gives no protein test after 24 hours' hydrolysis. The hydrolysate obtained by 72-120 hours' hydrolysis , contains quantities of pepton- and, residual nitrogen quite analogous to that of shoyu-moromi fermented for 8 or 10 months, while contains quantity of amino nitrogen only half that of shoyumoromi aforementioned, corresponding only 25 % of amino nitrogen of complete hydrolysate. 4) The hydrolysate is almost tasteless, and does not ,give unpleasant odor which is always perceptible in acid hydrolysate obtained at higher temperature. 5) The fermentation of the hydrolysate has been tried by adding a small amount of shoyu-koji. About 90 days' fermentation gives rise to a product quite similar to the ordinary fermented shoyu.