Changes in the pomological and biochemical properties of some jujube (Ziziphus jujuba Mill.) genotypes at three different edible development periods of fruits

This study was conducted in 2021 to determine the quality characteristics of the fruits of 15 jujube genotypes grown from seeds in a commercial jujube garden in the Çivril/Denizli ecology at different maturity periods. For this purpose, some pomological and antioxidant properties were investigated in the samples taken in three different edible mature stages of fruits (green-white, semi reddish and full reddish). The fruit weight, fruit width, fruit length, fruit flesh hardness, L*, h*, C*, water soluble solute content (SSC), titratable acidity (TA), total phenolic substance, total flavonoid and total antioxidant activity values of the genotypes varied between 7.33-20.35 g, 23.88-35.32 mm, 24.23-40.95 mm, 2.89-5.61 lb, 71.55-81.98, -73.92- -66.51, 39.15-47.88, %7.35-17.37, 0.071-0.241 g/100ml, 16.49-28.90 mg GAE/g DW and 1.68-6.69 mg CE/g DW, respectively, in the green-white mature stage and between 8.16-23.61 g, 24.77-35.03 mm, 24.28-44.88 mm, 2.28-5.19 lb, 72.93-80.29 (green-white skin) and 35.58-45.21 (reddish skin), -78.85- -67.73 (green-white skin) and 41.80-66.98 (reddish skin), 39.76-47.18 (green-white skin) and 27.48-39.04 (reddish skin), %14.90-22.80, 0.122-0.330 g/100ml,16.21-29.02 mg GAE/g DW, 1.58-6.33 mg CE/g DW and 1.58-3.24 mmol TE/g, respectively, in semi-reddish mature stage and between 7.82-21.94 g, 23.90-34.56 mm, 23.11-43.52 mm, 2.46-4.74 lb, 34.16-41.79, 37.27-59.40, 24.54-36.45, %15.90-25.85, 0.142-0.352 g/100ml, 10.90-20.34 mg GAE/g DW, 0.67-4.22 mg CE/g DW and 0.17-1.27 mmol TE/g, respectively, in the full reddish mature stage. As maturity progressed, the contents of SSC and TA increased. On the other hand, the total phenolic, total flavonoid and total antioxidant activity contents decreased. As a result, it was concluded that jujube fruits would be suitable for fresh consumption in the semi reddish ripe period in terms of phenolic, antioxidant, taste and flavor.