LONG-TERM STORAGE AND CONTROLLED ATMOSPHERE AFFECT ANTIOXIDANT PROPERTIES AND SENSORY QUALITY OF NEW 'GALA'-TYPE APPLE CULTIVARS

Fruit of the cultivar ‘Galaxy’ and of three new apple cultivars (‘Gemini’, ‘Renoirciv’ and ‘Gaia’) were evaluated at 1°C in regular (RA) or controlled (CA) atmosphere during a 6-months storage. Two static CA compositions were assessed: CA1 (1.7% O₂ + 1% CO₂) and CA2 (1.2% O₂ + 1% CO₂). At harvest and after 60 and 180 days, total phenols content (TPC), chlorogenic acid (CH) and antioxidant activity (AA) (evaluated by DPPH and FRAP tests) were measured in the fruit peel and flesh. Sensory analysis for sweetness, acidity, aroma, firmness, mealiness and juiciness was carried out by a trained panel, while firmness, titratable acidity, soluble solids content, color and ethylene production were measured analytically. During storage, TPC, CH and AA increased in the flesh and in the peel of all the cultivars. The effect of controlled atmosphere on nutritional quality was cultivar-dependent: after 6 months, both FRAP and DPPH test showed a higher antioxidant activity in RA-stored fruit of ‘Gemini’ and ‘Gaia’, while no significant differences among storage atmospheres were reported for ‘Galaxy’ and ‘Renoirciv’. TP, CH and AA were always highest in the peel than in the flesh. Storage time, storage treatments and cultivar had a significant effect on sensory scores for firmness, mealiness and acidity while they did not affect sweetness and aroma. Sensory and instrumental results indicated that CA2 was the best treatment to maintain the quality of ‘Renoirciv’, ‘Gemini’ and ‘Gaia’ during a long-term storage, while in ‘Galaxy’ RA-storage allowed a higher perception of aroma and sweetness. All cultivars could retain their antioxidant properties during a long-term storage; a more suitable effect of the CA2 regime was observed for their sensory and instrumental quality characteristics.