Ester synthesis by lactic acid bacteria isolated from goat’s and ewe’s milk and cheeses

ABEIJÓN MUKDSI C; MEDINA R; ALVAREZ MF; GONZÁLEZ S

FOOD CHEMISTRY

Elsevier

Lugar: Reading - Whiteknights - UK; Año: 2009 vol. 117 p. 241 - 247

0308-8146

The present work evaluates the ability of lactic acid bacteria isolated from goat’s and ewe’s 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 buffer phosphate containing triglyceride plus ethanol (alcoholysis) and free fatty acid plus ethanol (esterification). After 24 h 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 ethylbutanoate and ethylhexanoate. 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. Keywords: esters – esterification – alcoholysis - lactic acid bacteria