GEL-FILTRATION CHROMATOGRAPHY OF BROWNED COMPOUNDS IN HEATED ONION

Onion juice browned by heating was chromatographed on a Sephadex G-50 column. Browned compounds in the onion juice were fractionated into fi ve peaks designated as A, B, C, D and E according to the elution order . Optical density at 400 nm of peak B increased by browning. Elution v olume of peak B was a little larger than that of sugar or amino acid. The yield of non-dialyzable melanoidin of browned onion juice was 1/5 of total melanoidin. These results suggested that the main browned com pounds of heated onion juice are low in molecular weight compared with model melanoidin.