Development and origin of the volatile fatty acids in budu

The origin and mechanism of formation of the volatile fatty acids (VFA) present in budu were investigated. The acids did not appear to derive from the breakdown of the fish lipid. When the fish was allowed to spoil, a single bacterial species predominated, and as the fermentation progressed, the appropriate VFA were formed. Using (U −14 C)‐protein hydrolysate it was shown that amino acids are the precursors of the n ‐butanoic and n ‐pentanoic acid and also contributed to the formation of other acids. The bacterium did not use glucose as a carbon source nor did any particular combination of unlabelled amino acids produce the fatty acids. The metabolic route by which the fatty acids are produced from the amino acids is not known. An experiment that allowed spoilage to occur, prior to salting, in the normal environment involved in the preparation of budu, showed that the VFA were produced.