Enhancement of ethyl ester and flavour formation in Swiss cheese by ethanol addition

Esters are common flavour compounds of cheese. Our aim was to investigate the impact of esters on the flavour of Swiss cheese. Swiss cheeses were manufactured without (controls) or with (E) addition of ethanol to induce variations in ethyl ester concentrations. Cheese flavour was characterized by quantitative and qualitative (frequency of perception of 53 attributes) sensory evaluation. E cheeses contained similar to 9 times more ethanol (137 mu g g(-1)) and similar to 30 times more ethyl esters (26-172 ng g(-1)) than the controls. All cheeses had a typical Swiss cheese flavour. However, E cheeses were characterized by greater frequencies of perception of 'apricot/peach', 'caramel', 'pear', and 'pepper' odours, 'walnut' aroma, and a lower frequency of 'soap' odour and 'cooked cabbage' aroma. These results confirm that ethanol limits ethyl ester synthesis in Swiss cheese, show that moderate concentrations of ethanol are sufficient to induce perceptible flavour changes, and open new possibilities to diversify cheese flavour. (c) 2008 Elsevier Ltd. All rights reserved.