EFFECT OF ONION JUICE ON THE POLYMERIZATI ON OF MELANOIDIN IN A MODELSYSTEM

Polymerization of the melanoidin in a heated onion juice and a model s ystem of glucose and glycine was investigated by dialysis and gel filt ration chromatography on a Sephadex G-25 column. The melanoidin in a h eated-onion juice was eluted in the fractions of smaller molecular wei ght than those of sugar and amino acid, with a similar chromatography to caramel rather than these of model melanoidin and soy sauce. Adding onion juice to the model system of glucose and glycine, the ratio of dialyzable melanoidin in the whole melanoidin increased. The inhibitor y effect of onion juice on the polymerization of melanoidin was specul ated.