CHARACTERIZATION OF MUTAGENIC ACTIVITY IN INSTANT HOT BEVERAGE POWDERS

Extracts of several grain-based coffee-substitute blends and instant c offees were mutagenic in the Ames/Salmonella test using TA98, YG1024, and YG1029 with metabolic activation. The beverage powders induced 150 to 500 TA98 and 1,150 to 4,050 YG1024 revertant colonies/g, respectiv ely. Increased sensitivity was achieved using strain YG1024. No mutage nic activity was found in instant hot cocoa products. The mutagenic ac tivity in the beverage powders was shown to be stable to heat and the products varied in resistance to acid nitrite treatment. Differential bacterial strain specificity, and a requirement for metabolic activati on suggest that aromatic amines are present. Characterization of the m utagenic activity, using HPLC and the Ames test of the collected fract ions, showed the coffee-substitute blends and instant coffees contain several mutagenic compounds. Known heterocyclic amines are not respons ible for the major part of the mutagenic activity. The main mutagenic activity in grain-based coffee-substitute blends and instant coffees i s due to several unidentified compounds, which are most likely aromati c amines. (C) 1995 Wiley-Liss, Inc.