Pre-Harvest Oxalic Acid Application Improves Fruit Size at Harvest, Physico-Chemical and Sensory Attributes of ‘Red Flesh’ Apricot During Fruit Ripening

Abstract

Apricot is a highly nutritive stone fruit which ripens quickly after harvest and exhibits rapid fruit quality deterioration at ambient conditions. The current research work was executed to evaluate the effect of pre-harvest application of oxalic acid (OA); (0, 0.5, 1, and 2mM) on fruit quality of ‘Red Flesh’ apricot during fruit ripening at shelf under ambient conditions (25±1 °C; 60-65% RH). Fruit size, average fruit weight, fruit juice percentage was determined at harvest. While, fruit weight loss, fruit colour, fruit firmness, titratable acidity (TA), soluble solid contents (SSC), ratio of SSC to TA, ascorbic acid, total phenolics content (TPC), anti-oxidative scavenging activity (ASA), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) enzymes activity were determined during fruit ripening. Fruit sensory attributes (fruit pulp colour, fruit taste, fruit flavour and overall acceptability were determined at fruit ripening. Pre-harvest application of 2mM-OA was found the most effective in improving fruit size, average fruit weight, juice percentage at harvest, about 5%, 6% and 15% higher than control, respectively. Additionally, pre-harvest application of 2mM-OA retained higher fruit firmness, ascorbic acid, TPC, ASA and activities of POD, CAT enzymes in apricot fruit during fruit ripening at ambient conditions. On day-5 of fruit ripening 2mM-OA-treated apricot fruit exhibited about 28%, 20%, 17%, 7%, 9% and 23% higher fruit firmness, ascorbic acid, TPC, ASA and activities of POD, CAT enzymes, respectively as compared to control. Moreover, significant lower fruit weight loss (35%), SSC (20%) and SSC:TA ratio (30%) were exhibited by the apricot fruit treated with 2mM-OA than unsprayed apricot fruit. However, fruit treated with 1 mM-OA exhibited better fruit sensory attributes compared to other treatments at fruit ripening. Conclusively, pre-harvest application of 2 mM-OA improved the fruit size, delayed fruit ripening, and retained higher fruit antioxidants of apricot at ambient conditions.