Aging-induced variation in quality of yakju prepared using different commercial yeasts

Abstract

This study demonstrated the effects of different commercially available Saccharomyces cerevisiae yeasts i.e., Fermivin®, La Parisienne, Songcheon, Ottogi, and Chungmoo, on the variation in the quality of yakju samples under accelerated aging (45°C, 14 d). The analyses of physicochemical properties of the yakju samples were performed for, soluble solid content (°Brix), pH, total acid content (%, as acetic acid), alcohol (v/v%), volatile acid (mg/L), reducing sugar content (mg/mL), amino acidity (mL), brownness (A430), and hunter color value before and after aging. By comparing the results, significant differences in the properties of the yakju samples before and after aging were observed. The yakju sample fermented with wine-yeast Fermivin® exhibited no significant change in color after aging; furthermore, the reducing sugar content (1.20±0.01-1.32±0.03 mg/mL) and amino acidity (4.06±0.07-4.80±0.04 mL) of this sample were lower than those of the other samples. The yeast of Fermivin® resulted in a negligible residual sugar content owing to complete fermentation, thereby minimizing the variation in quality during aging. The using of different yeasts for fermentation induced significant differences in the contents of organic acid, free nitrogenous components, and volatile components before and after aging. The obtained results indicated that the properties of yakju such as odor and browning, could be regulated based on the type of yeast used for fermentation.