LAUSR

Abstract This study examined for the first time the effect on malolactic fermentation of an autochthonous Oenococcus oeni PG-16, which was isolated following alcohol fermentation of red-fleshed apple cider. The chemical composition and volatile characteristics of red-fleshed apple ciders produced via simultaneous and sequential inoculation of yeast with either PG-16 or a commercial O. oeni 1 strain were examined. The fermentations were monitored by measuring cell viability and organic acid metabolism. Irrespective of the inoculation mode, malic acid and citric acid were rapidly degraded in the presence of PG-16 during alcoholic fermentation in comparison with the control. These changes were accompanied by increases in lactic acid, acetic acid, ethyl lactate, acetate esters, pH, fatty acids and terpenes, although higher alcohols were unchanged. Cider obtained after inoculation with PG-16 had a sensory evaluation profile dominated by fruits and floral notes linked to esters, and to butter and creamy notes associated with ethyl lactate and 2,3-butanediol that enhanced the global aromatic intensity. Our findings suggest that simultaneous inoculation using the Excellence XR yeast strain and the O. oeni PG-16 lactic acid bacterial strain is an effective method for preparing red-fleshed apple cider.