Effect of the farming system and postharvest frozen storage on quality attributes of two strawberry cultivars

Introduction. Consumer interest in organic fruit is increasing based on the assumption that these products are healthier, despite a lack of conclusive evidence. Strawberry (Fragaria x ananassa Duch.) is a rich source of antioxidants and an important fruit in the human diet. Materials and methods. The configuration of strawberry fruit quality was analyzed in a factorial approach accounting for the effects of the farming system and postharvest frozen storage. The strawberry cultivars 'Sabrina' and 'Ventana' grown under organic and conventional farming management were stored postharvest at -40 degrees C for 6 months. Fruits obtained under the two farming systems were analyzed fresh after harvest and thawed after frozen storage. Fruit quality was evaluated in terms of physical, chemical and phytochemical properties. Results and discussion. The surface lightness, firmness, lipophilic antioxidant activity, soluble solids, ascorbic acid and ellagic acid contents were significantly higher at harvest than after thawing. Frozen storage increased only hydrophilic antioxidant activity, leaving reducing sugars and total phenols without significant alterations. The color of organic fruits in both cultivars was brighter and more vivid (higher L* and C* values). Farming management did not affect the reducing sugars and ascorbic acid contents for the 'Sabrina' (4.6% and 55.5 mg 100 g(-1) FW, respectively) or 'Ventana' (4.0% and 31.2 mg 100 g(-1) FW, respectively) cultivars. The organic 'Ventana' strawberry had higher soluble solid content and hydrophilic antioxidant activity, whereas an opposite trend was observed in total phenols and ellagic acid contents for 'Ventana' and 'Sabrina', respectively. Conclusion. The quality of strawberries, in particular the bioactive compounds, varied according to the farming system and postharvest frozen storage. The cultivation factors, including the farming management and cultivar, may significantly interact to affect quality attributes of strawberry fruit.