NEW 3-CHLORO-1,2-PROPANEDIOL DERIVED DIHYDROXYPROPYLAMINES IN HYDROLYZED VEGETABLE PROTEINS

Reaction products of 3-chloro-1,2-propanediol (the main contaminant of protein hydrolysates produced by hydrochloric acid hydrolysis; used as food seasonings) with ammonia in model aqueous solutions were analyzed, and except for the already known compounds (glycerol, 3-amino-1,2-propanediol, 2-amino-1,3-propanediol) bis(2,3-dihydroxypropyl)amine and tris(2,3-dihydroxypropyl)amine were newly identified. Commercial seasonings, a soybean meal hydrolysate containing more than 400 mg kg-1 of 3-chloro-1,2-propanediol, and an alkaline-treated hydrolysate containing less than 1 mg kg-1 3-chloro-1,2-propanediol were analyzed, and bis(2,3-dihydroxypropyl)amine (in concentrations of 6 and 3 mg kg-1, respectively) and tris(2,3-dihydroxypropyl)amine (2 and 4 mg kg-1, respectively) were newly identified as protein hydrolysates chemical constituents. Mass spectra of their silyl derivatives and H-1 and C-13 NMR spectra of these newly found compounds in foods are presented.