Abstract:To investigate the effects of relative humidity （RH） on apple quality at a shelf temperature of （14 ±1） ℃， samples were stored under conditions of 50%， 60%， 70%， 80%， 90%， and 100% RH for 24 d， and their nutritional qualities， physicochemical characteristics， anti-browning properties， and total antioxidant capacity were measured. The results showed that 100% RH reduced weight loss and firmness deterioration in apples， thereby preserving their freshness and textural characteristics. It delayed the occurrence of the maximum soluble solids content and accelerated the conversion of organic acids into sugars. During the early stages of storage， 100% RH regulated the L-phenylalanine metabolism pathway， inhibiting the synthesis of browning substrates， while in the later stages， it further inhibited the activity of polyphenol oxidase， reducing flesh browning. Additionally， 100% RH better maintained the integrity of the cell wall structure， suppressed the increase in malondialdehyde content， and enhanced peroxidase activity， thus preventing membrane lipid peroxidation. In conclusion， the 100% RH condition positively influenced postharvest quality control and freshness preservation in apples.