College of Mechanical and Electrochemical Engineering, Tarim University, Arar, 843300, China.
College of Mechanical and Electrical Engineering, Fujian Agricuture and Forestry University, Fuzhou, 350000, China.
Sci Rep. 2023 Oct 4;13(1):16732. doi: 10.1038/s41598-023-43594-w.
Dry processing is ineffective in preserving fresh jujubes (Zizyphus jujuba Mill.), contributing largely to the delayed jujube harvest in Xinjiang. However, no studies have evaluated the impact of delayed harvest periods on processing quality. Therefore, the present study investigated the effects of different delayed harvest periods on the characteristics of the quality of jujubes in Xinjiang after hot air drying. Six batches (S1-S6) were sampled over a 7-d period. Various indicators of jujubes changed significantly during the extended harvest period (P < 0.05). The water content of the fruit decreased progressively. While the percentages of soluble solids, total sugars, and reducing sugars increased continuously, the total weight of these parameters in a single jujube fruit decreased continuously. The proportion of ascorbic acid, total weight, and drying time decreased steadily. The fruit had the highest ascorbic acid content at the S4 stage after hot air drying (87.14 mg 100 g). Fewer color differences were recorded in hot air-dried fruits as compared with fresh jujubes; the cracking rate decreased after hot air drying, but the fruit could be rehydrated more effectively. A comprehensive evaluation revealed that jujubes harvested in the S4 stage were better suited for dry processing.
干制加工在保持鲜枣（Zizyphus jujuba Mill.）的新鲜度方面效果不佳，这在很大程度上导致了新疆红枣的收获期延迟。然而，目前还没有研究评估延迟收获期对加工质量的影响。因此，本研究调查了不同延迟收获期对新疆红枣热风干燥后加工品质特性的影响。在 7 天的时间内，共采集了 6 批（S1-S6）样本。在延长的收获期内，枣果的各种指标发生了显著变化（P<0.05）。果实水分含量逐渐降低。与此同时，可溶性固形物、总糖和还原糖的百分比持续不断地增加，而单个枣果中这些参数的总重量持续不断地减少。抗坏血酸、总重量和干燥时间的比例稳步下降。在热风干燥后，S4 期的枣果具有最高的抗坏血酸含量（87.14mg/100g）。与鲜枣相比，热风干燥后的枣果颜色差异较小；热风干燥后裂果率降低，但果实的复水能力更强。综合评价表明，S4 期收获的枣果更适合干制加工。
