Genetic toxicology evaluation of commercial beers. I. Development of procedures for the preparation of extracts from commercial beer products.

Commercial beer was subjected to an investigation in order to establish standard conditions for preparing organic solvent extracts to be used in short-term genetic screening assays. Test samples for use in the evaluation were prepared by mixing several brands of commercially available beer into a composite pool which was then spiked with the mutagen, 2-nitrofluorene. The composite sample was then concentrated using varying ratios of beer to XAD-2 resin in a 1.5 cm X 30 cm column. Dry-weight analyses indicated that significant amounts of residue could be trapped by XAD-2 resin. Columns were sequentially eluted by methylene chloride, acetone and methanol followed by evaporation of the solvents under nitrogen gas. Residues from commercial products were not mutagenic, but mutagenic activity could be detected in residues from spiked beer, yielding nearly 90% of the expected biological activity in S. typhimurium TA98. A standard method amenable to processing large volumes of beer products was devised for application to other projects.