College of Plant Sciences, Tarim University, Alar, 843300, Xinjiang, China.
The National-Local Joint Engineering Laboratory of High Effciency and Superior-Quality Cultivation and Fruit Deep Processing Technology on Characteristic Fruit Trees, Alar, 843300, Xinjiang, China.
Sci Rep. 2022 Feb 10;12(1):2272. doi: 10.1038/s41598-022-06313-5.
Jujube is a crop highly resistant to drought and salinity, making it one of the main fruit trees in Xinjiang. The present study evaluated the changes in the physicochemical and antioxidant activities of jujube fruit of eight different cultivars from Xinjiang, China. The developmental stages were selected according to the days after full bloom and fruit peel colour during ripening; these stages included young (S1), fruit core-hardening (S2), green ripening (S3), half-red maturity (S4) and complete red. In present study, different cultivars of jujube fruit showed similar chemical profiles, but their amounts showed great variation. HZ had the highest content of sugars, and JY had the highest content of cAMP and cGMP, while relatively higher levels of ascorbic acid, catechin, epicatechin, rutin, proanthocyanidin and antioxidant activity were found in 'FS' than in other cultivars, indicating that 'FS' could be used as a potential natural antioxidant. Regarding the development stages of jujube fruit, the moisture, ascorbic acid, total polyphenol, catechin, epicatechin, proanthocyanidin and rutin contents decreased during the development of all jujube cultivars, while the fructose, glucose, sucrose, cAMP, and cGMP contents greatly increased. The antioxidant activity determined by DPPH and ABTS radical scavenging decreased as the fruits matured. Therefore, the results suggest that green jujube (S1) could be used for natural antioxidants (catechin, epicatechin, proanthocyanidin) and that the advanced ripening stage(S5) is the proper picking period for fresh fruit and commercial processing.
红枣是一种抗旱、耐盐的作物，是新疆主要的果树之一。本研究评估了来自中国新疆的 8 个不同品种红枣果实的理化性质和抗氧化活性的变化。根据盛花后天数和果实成熟过程中果皮颜色选择发育阶段；这些阶段包括幼果期（S1）、硬核期（S2）、绿熟期（S3）、半红成熟期（S4）和全红期。本研究中，不同品种的红枣果实表现出相似的化学成分，但含量差异很大。HZ 品种的糖含量最高，JY 品种的 cAMP 和 cGMP 含量最高，而 'FS' 品种的抗坏血酸、儿茶素、表儿茶素、芦丁、原花青素和抗氧化活性相对较高，表明 'FS' 可作为潜在的天然抗氧化剂。关于红枣果实的发育阶段，所有红枣品种的水分、抗坏血酸、总多酚、儿茶素、表儿茶素、原花青素和芦丁含量在果实发育过程中逐渐下降，而果糖、葡萄糖、蔗糖、cAMP 和 cGMP 含量则大幅增加。DPPH 和 ABTS 自由基清除能力测定的抗氧化活性随着果实成熟而降低。因此，研究结果表明，绿枣（S1）可用于天然抗氧化剂（儿茶素、表儿茶素、原花青素），而晚熟期（S5）是鲜食和商业加工的适宜采摘期。
