Blueberry leaf extracts incorporated chitosan coatings for preserving postharvest quality of fresh blueberries

•Eight phenolic compounds were detected in blueberry fruit and leaf extracts.•Blueberry leaf extracts had high antimicrobial ability.•Chitosan coating containing leaf extract showed some degrees of delaying fruit decay.•Coated fruit with MA packaging controlled decay and retained phenolic content. The phenolic compounds in blueberry (Vaccinium spp.) fruit and leaf extracts (BLE) were determined based on HPLC analysis. Antimicrobial assays against Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and Escherichia coli, as well as fungi isolated from the rotting blueberry fruit were conducted. The effects of chitosan coating incorporating different concentrations of BLE on the quality of fresh fruit during postharvest storage at 2±1°C and 95±2% relative humidity (RH) for 35d and then at room conditions for 3d were also investigated. Five different coating treatments were applied including 2% (w/v) chitosan coating (T1), 2% (w/v) chitosan coating containing 4% (w/v, T2), 8% (w/v, T3), or 12% (w/v, T4) BLE, and 2% (w/v) chitosan coating containing 12% BLE plus modified atmosphere packaging (MAP at 3kPa O2+12kPa CO2) (T5). A sample of blueberries dipped into distilled water was used as control (T0). BLE had a greater variety of phenolic compounds than fruit extracts with syringic acid the highest concentration (0.259±0.003gkg−1), but the total phenolic content in BLE was lower (P