Effect of Carbon Dioxide-Enriched Atmosphere during Cold Storage on Limiting Antioxidant Losses and Maintaining Quality of ‘Barhy’ Date Fruits

Abstract

Mature ‘Barhy’ date fruits (Phoenix dactylifera L.) were stored under different storage temperatures (0, 2, 4, 6°C) under modified atmosphere (MA) conditions with 0.03, 5, 10, or 20% carbon dioxide concentrations (balance air). Fruit total phenolic content (TPC), flavonoids content, carotenoids content, total sugar %, SSC %, and fruit skin color (L*a*b*c* and h*) were determined. Total phenolic content (TPC) was determined by the Folin-Ciocalteu method, and antioxidant capacity was determined using ferric reducing antioxidant power (FRAP). A clear integration was observed between modified atmosphere and cold storage treatments regarding maintaining fruit quality during the storage period. Fruits stored under low temperature conditions (0°C) or relatively high CO2 concentration (20% CO2) did not show any chilling or CO2 injury symptoms. Fruits kept under MA conditions with 20% CO2 at cold storage (0°C) showed brightest yellow color, and highest storage ability among all stored fruits. All MA conditions investigated extended date storability by maintaining fruit quality. The effect of MA conditions on maintaining fruit quality was magnified when fruits were stored under cold temperature. Fruit quality was maintained for 173 days when stored in 20% CO2 at 0°C, whereas it did not exceed 60 days when stored under common air composition (containing 0.03% CO2) at 0°C. Treatments with high CO2 concentrations (20% CO2) under cold storage conditions (0°C) maintained fruit total phenolic content, SSC%, total sugar content, and total tannins.