Improving fruit cluster quality attributes of 'Flame Seedless' grapes using preharvest application of ascorbic and salicylic acid

The effectiveness of ascorbic acid (AA) and salicylic acid (SA) at different concentrations (AA, 3 and 6 mM; and SA, 2 and 4 mM) of 'Flame Seedless' grapes spraying to improve fruit cluster quality or delay cluster deterioration during shelf life. Vines were received different AA and SA concentration tow time at véraison stages and 14 days before harvesting time. Fruit clusters were harvested when total soluble solid content reaches to 16%, then fruit clusters were stored at ambient air for four-day shelf life (28 ± 1 °C and air humidity 48 ± 2 during shelf life period). Samples were picked every day to measure physical and chemical attribute quality properties such as water loss, soluble solid content (SSC%), titrable acidity (TA%), berry firmness and separation force, rachis browning index, and berry color hue angle (h°). Riches browning parameters such as total phenol content (TP), flavonoids (TF), and poly phenoloxidase (PPO) activity. While cell wall degrading enzyme activities like polygalacturonase (PG; EC: 3.2.1.15), xylanase (XYL; EC:3.2.1.8), and cellulase (CEL; EC: 3.2.1.4). The AA 6 mM + SA 4 mM treatment was delayed fruit cluster deterioration during shelf life by minimizing cell wall degradation enzyme activities, maintaining the phenolic compounds. So, less rachis browning symptoms, and preserving the chemical and physical of a fruit cluster quality attribute during shelf life.