Synergistic Fermentation of <i>Pichia kluyveri</i> and <i>Saccharomyces cerevisiae</i> Integrated with Two-Step Sugar-Supplement for Preparing High-Alcohol Kiwifruit Wine

Abstract

Wild yeast suitable for kiwifruit wine fermentation was isolated and purified, and the fermentation process was optimized to increase the alcohol content of the kiwifruit wine. Pichia kluyveri was isolated from kiwifruit pulp by lineation separating, screened by morphological characteristics in Wallerstein Laboratory Nutrient Agar (WL) medium and microscope observation, and further identified by 26S rDNA D1/D2 domain sequence analysis. Taking alcohol content and sensory evaluation as two indexes, the fermentation condition for kiwifruit wine was optimized by single factor and response surface experiment. The optimal fermentation conditions were optimized as follows: the fermentation temperature was at 24 °C, the initial pH was 3.8, the sugar dosage in second step was 8% (w/w), and the inoculating quantity of Pichia kluyveri and Saccharomyces cerevisiae was 0.15 g/L at equal proportion. Under these optimal conditions, the maximum estimated alcohol content was 15.6 vol%, and the kiwifruit wine was light green in color with strong kiwifruit aroma and mellow taste.

Keywords

• kiwifruit wine
• wild yeast
• 26S rDNA D1/D2
• synergistic fermentation
• <i>Pichia kluyveri</i>
• two-step sugar supplement