Ester synthesis by lactic acid bacteria isolated from goat and ewe milk and cheeses (autor de correspondencia)

ABEIJÓN MUKDSI, M.C., MEDINA, R. , ALVAREZ, M. F. Y GONZÁLEZ, S

FOOD CHEMISTRY

ELSEVIER SCI LTD

Año: 2009 vol. 117 p. 241 - 247

0308-8146

The present work evaluates the ability of lactic acid bacteria isolated from goat  and ewe milk and cheeses to synthesise short-chain fatty acid esters. In order to elucidate the mechanisms of ester synthesis involved, cell-free extracts were incubated in sodium phosphate buffer containing triglyceride plus ethanol (alcoholysis) and free fatty acid plus ethanol (esterification). After 24h incubation at 37°C esters were extracted and determined by gas chromatography. Strains evaluated were able to synthesise ethyl esters from 2 to 10 carbon atoms, mainly ethyl butanoate and ethyl hexanoate. A great variability amongst strains was observed. In general, higher ester-forming activities by esterification were detected. In enterococci strains the alcoholysis mechanism was also involved. These strains could be useful as adjunct cultures for small ruminants´ dairy products and would contribute to the development of fruity flavour notes. A deeper understanding of ester synthesis mechanisms involved would allow the control of flavour development