Factors Affecting S-Methylmethionine Levels in Malt. W. J. Pitz, Canada Malting Company Limited, Toronto, Canada, M5A 1C2. J. Am. Soc. Brew. Chem. 45:0053, 1987.

The effects of genotype, environment, processing, and barley storage on S-methylmethionine (SMM) levels in malt were investigated. Laboratory maltings of samples of commercial barley varieties and plant breeders' cultivars from various barley breeding programs showed genotype and environment to have statistically significant effects on malt SMM. High barley protein content and good modification during malting were shown to increase levels. Indexes of malt modification revealed barleys that produced low levels of SMM under a given set of malting conditions were inferior in terms of modification. Processing adjustments offered only limited control of SMM in finished malt. Steeping and germination manipulations that restricted modification resulted in reduced synthesis of SMM, and increased kilning temperatures enhanced SMM breakdown. However, other items of malt analysis were adversely affected by these processing adjustments. Of several processing additives investigated, only potassium bromate effectively lowered malt SMM levels.

Keywords: Malt, S-Methylmethionine, Control measures, Genotype, Environment, Processing