High CO2 atmosphere enhances fruit firmness during storage

Abstract

Strawberries were subjected to air or 20% CO2 + air at 2.2 °C for 2 days. Firmness of strawberries increased under high CO2 treatment by 20-30%. Cell wall analysis showed lower water soluble pectin and higher chelating soluble pectin in CO2 treated strawberries. Viscosity of water soluble extract from alcohol soluble solids was lower in CO2 treated strawberries, and could be influenced by the change in pH. The enhanced firmness effect was also observed in mature mangoes, but not in immature and fully mature mangoes. The mechanism of firmness enhancement by CO2 was possibly due to the change in intercellular pH and its solute composition.