Effect of carboxymethyl chitosan-gelatin-based edible coatings on the quality and antioxidant properties of sweet cherry during postharvest storage

Abstract

The effects of various carboxymethyl chitosan (CMCS)-gelatin (GL) based edible coating combinations with calcium chloride (CaCl2) and/or ascorbic acid (AA) on the quality and antioxidant properties of sweet cherry (Prunus avium L. cv. “Red Agate”) were investigated. Sweet cherries were treated with tap water (control), 2 % CaCl2, CMCS-GL, CaCl2 + CMCS-GL, CaCl2-CMCS-GL, or AA-CaCl2-CMCS-GL for 2 min and dried at ambient temperature. All fruit were stored at 0 ± 0.5 °C under Relative Humidity (RH) of 85–90 % for 30 d, and 23 ± 1 °C, RH 40-50 %, for a further 3 d. Weight loss, fruit firmness, soluble solids content (SSC), titratable acidity (TA), SSC/TA, AA, skin color characteristics (L⁎, chroma, and hue angle), total phenolics compounds (TPC), total anthocyanins concentration (TAC), and antioxidant activity (DPPH and ABTS+ radical scavenging capacity) were measured, in addition to fruit decay ratio, pedicel browning incidence, and pedicel moisture content. AA-CaCl2-CMCS-GL treatment decreased fruit decay ratio, weight loss, respiration rate, and pedicel browning incidence; slowed the increase of SSC and SSC/TA; maintained high fruit firmness, pedicel moisture content, TA, AA, TPC, TAC, and antioxidant activity. Fruit coated with AA-CaCl2-CMCS-GL exhibited better skin color with higher L⁎, chroma, and hue angle values throughout the storage period. AA-CaCl2-CMCS-GL treatment is a promising management strategy to control the quality of sweet cherries during postharvest storage.