High CO2 Prolongs Postharvest Life of Strawberry Fruit by Reducing Decay and Cell Wall Degradation

Abstract

Extending postharvest life of fruit, particularly strawberry, is a challenge due to rapid loss of firmness and freshness during ripening. To overcome this problem, short-term high CO2 treatment has been widely used to maintain firmness and reduce decay. Previous studies of high CO2 treatment have mostly been related to the issue of proper treatment concentration and time. However, the mechanism of the high CO2 treatment to maintain fruit firmness is still unclear. Therefore, the objective is to understand postharvest physiological mechanism by high CO2 in strawberry fruit after harvest. In this study, harvested strawberry fruit was stored at 10oC after 3 h of treatment with 30% CO2 or air. The effect on the cell wall and lipid metabolism was examined through pectin analysis and cell wall degradation-related gene expression. The high CO2 treatment maintained higher pectin content and firmness and lower decay compared to the control. Cell wall degradation-related gene expression was lower with high CO2 treatment. High CO2 induced oligogalacturonides and thereby provided the defence mechanism against Botrytis cinerea in strawberry fruit. High CO2 lowered decay incidence after 7 days after inoculation of Botrytis cinerea. The high CO2 treatment is expected to maintain the quality by reducing decay and cell wall degradation.