Effects of different storage temperatures on the shelf life and quality characteristics of winter jujubes

• Near-freezing temperature greatly reduced respiration and oxidative damage. • Freezing point was measured and applied to refine storage temperature settings. • A temperature-metabolism-oxidative stress-quality regulation chain was revealed. • Near-freezing temperature significantly extends shelf life to 70 days. • It has filled the gap in the mechanism of quality changes at different temperatures. This study investigated the effects of four storage temperatures—near-freezing temperature (NFT, -1 ± 1 °C), low temperature (LT, 2 ± 2 °C), near-low temperature (NLT, 12 ± 2 °C), and room temperature (RT, 22 ± 2 °C)—on the postharvest quality of winter jujubes. The freezing point of the fruit (-4.4 °C) was first determined and used to refine the NFT setting. Results showed that temperature strongly influenced respiratory metabolism, oxidative stress, and antioxidant defense, forming a typical temperature-metabolism-oxidative stress-quality regulatory chain. NFT significantly suppressed respiration, reduced Malondialdehyde (MDA) accumulation, and maintained higher activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Consequently, NFT best preserved total soluble solids (TSS), Titratable acidity (TA), phenolics, and ascorbic acid (AsA), while minimizing weight loss, firmness decline, and decay, resulting in the longest shelf life (70 d). LT also delayed deterioration but was less effective than NFT, whereas NLT and RT caused rapid quality loss. These findings highlight the central role of precise temperature management—particularly NFT—in maintaining postharvest quality of winter jujubes, providing practical guidance for cold-chain storage and commercial applications.