Physiological response, phytochemicals, antioxidant, and enzymatic activity of date palm (Phoenix dactylifera L.) cultivated under different storage time, harvesting Stages, and temperatures

Abstract

The quality of date palm is highly influenced by postharvest techniques, storage, and processing effects. Fruits stored at room temperature result in dehydration, whereas higher temperatures accelerate the enzymatic browning of fruit. This study aimed to enhance postharvest quality of date palms through improved harvesting and storage techniques. The fruits of date palm (Phoenix dactylifera L. cv. Dhakki) were harvested at khalal (mature, firm), rutab (fully ripe), or tamar (dry) stages and stored at different temperatures (12, 18, or 24 °C) for 0, 15, 30, or 45 days. The analysis of the data showed that the studied attributes significantly different at various ripening stages and storage temperatures. The fruits harvested at Khalal stage proved to be the best in retaining moisture content (23.16%), total soluble solids (20.36 oBrix), fruit juice pH (4.97), ascorbic acid (24.65 mg 100 g−1), non-reducing sugars (26.84%), percent acidity (0.39%), antioxidant activity (211.0 mg 100 g−1), total phenolic (40.07 mg100g−1), flavonoids (45.8 mg 100 g−1), tannin (70.7 mg100g−1), catalase (1.82 U g−1), peroxidase (1.4 U g−1), soluble protein (38.2 mg kg−1), brightness (29.9), chroma (16.4), hue angle (34.9), color (16.8), and with minimum weight loss (8.48%) as compared to fruit harvested at Rutab and Tamar stage. Regarding the means for storage temperature, the fruits stored at 12 ± 3 °C retained the highest moisture content (23.2%), total soluble solids (13.5 oBrix), fruit juice pH (5.42), percent acidity (0.29%), ascorbic acid (24.4 mg100g−1), reducing sugars (31.1%), non-reducing sugars (26.5%), antioxidant activity (214.6 mg100g−1), total phenolic (41.6 mg100 g−1), flavonoids (44.7 mg100 g−1), tannin (71.7 mg 100 g−1), catalase (1.56 U g−1), peroxidase (1.21 U g−1), soluble protein (31.8 mg kg−1), brightness (28.8), chroma (15.3), hue angle (29.6), color (16.2),with minimum weight loss (9.91%). It was concluded that for quality fruit production of date palm cv. Dhakki could be harvested at Khalal stage and stored at a temperature of 12 ± 3 °C.