Intermittent warming improves postharvest quality of bell peppers and reduces chilling injury

• Intermittent warming reduces chilling injury to peppers and extends storage life.
• Two intermittent warming cycles at 6 and 13 days after harvest were optimal.
• Cell microstructure and volatile flavor changes confirmed this result.
• Storage life was extended by 6–11 days and delayed chilling injury onset.
• Suitable timing and intermittent warming intervals are required for optimal storage.

The long-term low temperature storage of pepper fruit is currently risky because of the likelihood of chilling injury (CI), which reduces shelf-life. Intermittent warming (IW) has been proposed as a potential solution to enhance successful long-term pepper fruit storage. To understand the influence of IW in alleviating CI in peppers, the effects of 3 IW cycles were tested on the organic acid content, firmness, and relative enzyme content of pepper fruit (namely, 1–3 IW cycles to 20 °C for 24 h every 7 days for fruit stored at 4 °C for 27 days). Subsequently, the effects of 2 IW cycles were tested on the organizational structure of pepper fruit cells and potential odor changes. The results showed that IW effectively reduces the CI index and maintains pepper firmness. Following 2 IW cycles after 6 and 13 days storage, pepper integrity was retained, with no shrinkage or decay. Furthermore, partial least squares analysis of odor changes showed that both 1 IW cycle after 20 days storage and 2 IW cycles after 6 and 13 days storage extended storage time to over 10 days. The appropriate IW cycles effectively delay the decline in unsaturated fatty acid content and maintain a higher index of unsaturated fatty acids (IUFA), which helps retain the integrity of the pepper cell membranes.