Differential consumption of malic acid and fructose in apple musts by Pichia kudriavzevii strains.

ABSTRACT

AIMS: To assess the capability of Pichia kudriavzevii strains isolated from wine, cider, and natural environments in North Patagonia to produce ciders with reduced malic acid levels. METHODS AND RESULTS: Fermentation kinetics and malic acid consumption were assessed in synthetic media and in regional acidic apple musts. All P. kudriavzevii strains degraded malic acid and grew in synthetic media with malic acid as the sole carbon source. Among these strains, those isolated from cider exhibited higher fermentative capacity, mainly due to increased fructose utilization; however, a low capacity to consume sucrose present in the must was also observed for all strains. The NPCC1651 cider strain stood out for its malic acid consumption ability in high-malic acid Granny Smith apple must. Additionally, this strain produced high levels of glycerol as well as acceptable levels of acetic acid. On the other hand, Saccharomyces cerevisiae ÑIF8 reference strain isolated from Patagonian wine completely consumed reducing sugars and sucrose and showed an important capacity for malic acid consumption in apple must fermentations. CONCLUSIONS: Pichia kudriavzevii NPCC1651 strain isolated from cider evidenced interesting features for the consumption of malic acid and fructose in ciders.