IMPROVING THE BIOCONTROL EFFICACY OF PICHIA CARIBBICA WITH PHYTIC ACID AGAINST POSTHARVEST BLUE MOLD AND NATURAL DECAY IN APPLES

Abstract

Phytic acid integrated with Pichia caribbica or as separate treatments for the control of wound infections, spoilage of intact apple fruits and enzymatic activities were investigated. The combined treatment of P. caribbica and phytic acid (0.2% v/v) showed significant improvement in the control of Penicillium expan-sum infections on apples than either yeast or phytic acid alone. Disease incidence and lesion diameter in treated fruits were significantly lower than the control fruits after 10 days of storage (20 °C, RH 95%). P. caribbica treated with or without phytic acid significantly reduced the natural decay incidence, weight loss, browning index, while maintained the firmness, total phenolic compound, total soluble solids (TSS) and titratable acidity (TA) of the apples. Similarly, the combination of yeast and phytic acid led to increases of peroxidase (POD), polyphenoloxidase (PPO), catalase (CAT) and low malondialdehyde (MDA) activities. Therefore, phytic acid could be used as a potential elicitor against blue mold decay caused by P. expansum.