QUANTITATIVE DETERMINATION OF N-METHYL KETONES AND O-AMINOACETOPHENONE IN STERILIZED CONCENTRATED MILK

The odd-numbered n-methyl ketones (C3—C11) and o-aminoacetophenone in sterilized concentrated milk were quantitatively determined as 2,4-dinitropbenylhydrazones during storage at 27 C up to 26 weeks. The n-methyl ketones were found to exceed their average flavor thresholds (considering additive interactions) after 13 weeks of storage, although the levels never approached theoretical maximum concentrations, based on the amounts of precursor usually available. The concentration of o-aminoacetophenone was well above its threshold after 13 weeks, suggesting that this compound also contributes to stale flavor of the concentrated milk. © 1969, American Dairy Science Association. All rights reserved.