Abstract
Melanoidin produced during storage (37°C, 50 days) of soy sauce was purified and studied. The experimental results were as follows;
(1) The soy sauce melanoidin was purified by dialysis (against running water), DEAE-cellulose chromatography and Sephadex G-100 gel filtration. The purified melanoidin gave a single peak on Sephadex G-100 gel filtration and a single band on disc electrophoresis. No amino acids and reducing sugars were contaminated in the melanoidin.
(2) The color of melanoidin was not increased by heating and oxidation. Besides, it had no effect upon the browning of soy sauce on heating and oxidation.
(3) The melanoidin had considerable ability of reducing ferricyanide and uptaking oxygen.
(4) By hydrolysis, the melanoidin liberated sugars (Glc, Xyl, Gal, Ara) and all kinds of amino acids contained in soy sauce.
