Sustainable Use of Apple Juice By-product for the Propagation of Vishniacozyma victoriae in Batch and Semicontinuous Processes.

This study aimed to evaluate the use of apple juice (AJ), an agro-industrial by-product rich in sugars, as a low-cost substrate for the production of Vishniacozyma victoriae, a biocontrol yeast, and to assess the performance of the fresh and lyophilized biomass under semi-commercial postharvest conditions. A Central Composite Design was used to optimise culture medium composition for improve biomass production. Biomass production was then evaluated under different cultivation modes, batch and semicontinuous reactors at laboratory scale. The biomass was preserved by lyophilization using protective formulations and later applied in two commercial packinghouses. In organic Packinghouse A, the control percentages exceeding 50% and, in some cases, reaching 100% control for the decays caused by Penicillium expansum, Botrytis cinerea and Alternaria-Cladosporium spp. The antagonistic yeast was able to colonize the surface of the fruit during the postharvest period. Apple juice is a suitable substrate for the cost-effective production of biocontrol yeast. Semicontinuous cultivation enhanced biomass yield, and both fresh and lyophilized formulations were effective in reducing postharvest decay in pears and apples under semi-commercial conditions.