Volatile medium chain fatty acids and mutton flavor

Abstract

Mutton fat, cooked with or without meat added, produced a host of steam volatile fatty acids in trace amounts. These have been identified by GC-MS as medium chain normal, branched, unsaturated, oxygenated, and aromatic acids belonging to 11 homologous series. Odor properties of these acids have been evaluated and results in-dicate that the branched chain and unsaturated acids having 8 to 10 carbon atoms contribute to the undesirable flavor of cooked mutton. The 4-methyl branched Cg and Cio acids in particular are considered primarily responsible for the sweaty odor note described in Chinese as "SOO".

The contribution of 4-methyloctanoic (hircinoic) acid to mutton and goat meat flavour

“…The pattern of volatile fatty acids obtained from hydrolysis of mutton fats resembles in general that produced on heating the fat, and GC-MS analysis has shown that essentially the same series of acids are produced under both conditions (Wong et al 1975b). Differences between samples are manifest generally in the relative proportions of the odd and branchedchain acids present.…”

“…This strongly implies that other factors were contributing to the muttoniness in these samples. We have earlier concluded, independently from combined chemical and nasal appraisal studies, that other factors contribute to muttoniness and are present in the non-acid fraction of cooked mutton fat volatiles (Wong et al 1975b). This fraction is the subject of current investigations.…”

“…Although the odour of the compound is suggestively "sheepy" by smell alone (Wong et at. 1975a(Wong et at. , 1975b) a much more positive evocation of muttoniness was found in the present study when the acid was administered with mince and savoured by mastication.…”

“…This acid fraction was analysed by gas chromatography on 10% EGA as previously described (Wong et al 1975b), with typical separations as shown in Fig. 1.…”

“…These, together with other novel volatile acids, have been shown to be regular minor constituents of mutton fat from which they can be readily liberated by alkaline hydrolysis (Wong et al 1975b). This paper describes work aimed at correlating intensity of mutton flavour with quantitative levels of these acids in mutton fat.…”