The green hull of fresh walnuts (Juglans regia L.) is highly susceptible to browning and accompanied with deterioration of the walnut quality, and the currently available preservation technologies still do not meet the market threshold supply of fresh walnut. This study investigated the effect of controlled atmosphere (CA) storage alone and combination with 1-Methylcyclopropene (1-MCP) on hull browning and kernel quality of fresh in-hull walnut. Fresh in-hull walnuts were treated with air (Control), CA (5% O₂, 7.5% CO₂), 1-MCP (0.5 μL L⁻¹) + CA and stored at 0 ± 0.5 °C for 100 d. Browning incidence, hull redox metabolism, kernel color and walnut oil quality were analyzed. The results showed that CA promoted the activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), maintained total phenol (TP), γ-aminobutyric acid (GABA), ascorbic acid (ASA), and glutathione (GSH) contents, inhibited ethylene production, reduced reactive oxygen species (ROS) accumulation, and delayed the hull browning. Besides, CA attained the highest kernel quality through inhibited the decrease of kernel color value and moisture content, and reduced acid value (AV) and peroxide value (POV) of walnut oil. While 1-MCP + CA treatment increased the activities of antioxidant enzymes, the combination weakened the other positive effects of CA. However, hull browning and kernel deterioration in 1-MCP + CA were less than that observed in air control. Overall, CA was an effective method for the preservation of fresh in-hull walnut at 0 ± 0.5 °C.

新鲜核桃（Juglans regia L.）的绿色外壳极易褐变，并伴随核桃质量下降，并且当前可用的保鲜技术仍无法满足新鲜核桃的市场供应阈值。这项研究调查了单独控制气氛（CA）的存储以及与1-甲基环丙烯（1-MCP）的组合对新鲜壳核桃的壳褐变和仁品质的影响。新鲜在船体核桃用空气（控制）处理，CA（5％氧气₂，7.5％CO ₂），1-MCP（0.5μL大号^-1）+ CA，并在0±0.5°C下保存100 d。分析了褐变发生率，船体氧化还原代谢，果仁颜色和核桃油质量。结果表明，CA促进了超氧化物歧化酶（SOD），过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的活性，维持了总酚（TP），γ-氨基丁酸（GABA），抗坏血酸（ASA）和谷胱甘肽的活性。 （GSH）含量，抑制乙烯的产生，减少活性氧（ROS）的积累，并延迟船体褐变。此外，CA通过抑制核桃仁色值和水分含量的降低以及降低核桃油的酸值（AV）和过氧化物值（POV）而获得了最高的籽粒品质。1-MCP + CA处理虽然增加了抗氧化酶的活性，但组合削弱了CA的其他积极作用。然而，1-MCP + CA中的褐变和籽粒变质均低于空气控制中观察到的。总体而言，CA是在0±0.5°C下保鲜新鲜壳核桃的有效方法。