Abstract
BACKGROUND: Climate change in Spain is altering the optimal conditions for producing high-quality 'Mollar de Elche' pomegranate fruit, due to reduced colour development in husk and arils. In addition, the pomegranate requires storage above 7-10 °C, depending on cultivar, to preserve its quality because it is susceptible to chilling injury (CI) damage at lower temperatures. RESULTS: In this study, the effect of preharvest application of 0.01 and 0.1 mmol L(-1) spermidine (SPD) and putrescine (PUT) on crop yield and fruit quality at harvest was evaluated in two consecutive years, 2022 and 2023, and during cold storage at chilling temperature in fruit for the 2023 trial. Results showed that SPD and PUT, at 0.01 and 0.1 mmol L(-1), significantly increased crop yield and improved fruit quality parameters at harvest in the experiments carried out in 2022 and 2023. The application of polyamines (PAs) effectively alleviated CI after 30, 60 and 90 days of storage at 2 °C (85-90% RH) plus 2 days at 20 °C (55-60% RH) by reducing electrolyte leakage, malondialdehyde accumulation and peel browning. PAs also preserved fruit firmness and titratable acidity and decreased respiration rate and weight loss. In addition, the ripening index was significantly lower in PA-treated fruit compared to controls during the whole storage period. Finally, PAs increased total phenolic content in arils, especially anthocyanins, which intensified aril red colour. Notably, SPD at 0.01 mmol L(-1) was the most effective treatment in improving crop yield, red colour of husk and arils and anthocyanin content in arils with strong effects also in reducing CI symptoms. CONCLUSION: The findings demonstrate the potential of PAs, especially SPD at 0.01 mmol L(-1), as an effective and sustainable tool to improve crop yield, mitigate CI and preserve the quality of 'Mollar de Elche' pomegranate fruit during cold storage. Thus, PA treatments would lead to an increase in growers' income and health benefits for consumers, due to the enhanced bioactive compound content. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.