Preharvest Application of Oxalic Acid Increased Fruit Size, Bioactive Compounds, and Antioxidant Capacity in Sweet Cherry Cultivars (Prunus avium L.)

• Published in: Journal of agricultural and food chemistry 2014-04, Vol.62 (15), p.3432-3437
• Main Authors: Martínez-Esplá, Alejandra, Zapata, Pedro Javier, Valero, Daniel, García-Viguera, Cristina, Castillo, Salvador, Serrano, María
• Format: Article
• Language: English
• Subjects: acidity; anthocyanins; Anthocyanins - analysis; antioxidant activity; antioxidants; Antioxidants - analysis; cherries; chlorogenic acid; Color; cultivars; firmness; flavonols; Fruit - chemistry; Fruit - drug effects; Fruit - growth & development; functional properties; oxalic acid; Oxalic Acid - pharmacology; phenolic compounds; Phenols - analysis; Plant Extracts - analysis; preharvest treatment; Prunus - chemistry; Prunus - drug effects; Prunus - growth & development; Prunus avium; ripening; total soluble solids; trees
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf500224g

Trees of ‘Sweet Heart’ and ‘Sweet Late’ sweet cherry cultivars (Prunus avium L.) were treated with oxalic acid (OA) at 0.5, 1.0, and 2.0 mM at 98, 112, and 126 days after full blossom. Results showed that all treatments increased fruit size at harvest, manifested by higher fruit volume and weight in cherries from treated trees than from controls, the higher effect being found with 2.0 mM OA (18 and 30% higher weight for ‘Sweet Heart’ and ‘Sweet Late’, respectively). Other quality parameters, such as color and firmness, were also increased by OA treatments, although no significant differences were found in total soluble solids or total acidity, showing that OA treatments did not affect the on-tree ripening process of sweet cherry. However, the increases in total anthocyanins, total phenolics, and antioxidant activity associated with the ripening process were higher in treated than in control cherries, leading to fruit with high bioactive compounds and antioxidant potential at commercial harvest (≅45% more anthocyanins and ≅20% more total phenolics). In addition, individual anthocyanins, flavonols, and chlorogenic acid derivatives were also increased by OA treatment. Thus, OA preharvest treatments could be an efficient and natural way to increase the quality and functional properties of sweet cherries.