Formation of N-Nitrosodimethylamine in Direct-Fire Dried Malt. Mario M. Mangino and Richard A. Scanlan, Department of Food Science and Technology, Oregon State University, Corvallis 97331. J. Am. Soc. Brew. Chem. 40:0055, 1982.

The principal objective of this work was to investigate the formation and establish the identity of amine precursors for N-nitrosodimethylamine (NDMA) in direct-fire dried malt. NDMA levels in malt and beer samples were determined using a gas chromatograph coupled with a Thermal Energy Analyzer. A comparison of NDMA levels in nitrosated electric-dried and freeze-dried malt indicated that heat during kilning did not promote formation of precursor amines. Considerable amounts of NDMA were produced from dimethylamine, trimethylamine, hordenine, and gramine, whereas negligible NDMA levels were produced from N-methyltyramine, sarcosine, and choline upon aqueous phase nitrosation. Analysis of commercial samples of malt and beer revealed that NDMA levels have been sharply reduced in these commodities during the past several years.

Keywords: Amine precursors, Malt, Nitrosamines, N-nitrosodimethylamine.