Research concerning the influence of linoleic acid addition in wort comparing with wort aeration

Résumé

It is well known that yeasts need oxygen at the beginning of the fermentation process for the synthesis of essential compounds for cell membrane, like unsaturated fatty acids and ergosterols. Because the yeast needs the oxygen for the multiplication phase, the brewers aerate the cleared wort with 5-8 mg O2/l. Studies showed that yeast uses oxygen for lipid synthesis needed for cell membrane. It was also observed that yeast is able to use wort’s lipids which have generated the idea that, adding lipids in wort, especially unsaturated fatty acids, would be an interesting alternative for wort aeration. It was also demonstrated the negative implication of the fatty acids addition in aroma profile of the fermented wort. Based on these considerations the effect of linoleic acid addition in wort on the fermentation intensity and aroma compounds synthesis have been studied and compared to fermentation dynamics and aroma profile of the beer obtained from aerated wort.