FATTY ACIDS CONTRIBUTING TOCAPRYLICFLAVOUR IN BEER. THE USE OF PROFILE AND THRESHOLD DATA IN FLAVOUR RESEARCH

Abstract

Difference tests and flavour-description tests have been used to determine the effects of C₆-C₁₂ straight-chain fatty acids on beer flavour. Levels of hexanoic acid normally found in beer are insufficient to contribute substantially to caprylic flavour. On the other hand, the difference-threshold concentrations of octanoic acid (4·5 mg/litre), decanoic acid (1·5 mg/litre) and dodecanoic acid (0·6 mg/litre) are all within the range of concentrations of the respective compounds that have been found to occur in beer. Moreover, the effects of these three acids on caprylic flavour in beer are additive. The effects of the fatty acids on beer flavour agree with the results of odour characterization of pure samples of the four fatty acids in odourless media. Results of taste-panel tests can be critically affected by differences in the sensitivity of individual assessors to the flavour effect in question. This is a major source of variation in flavour-threshold values that are determined by small laboratory-panels of assessors.