Copolyamide-Based Modified Atmosphere Packaging Attenuates Phenolic Degradation and Maintains Postharvest Quality of Rubus Berries

The highly perishable nature of Rubus berries, particularly their susceptibility to water loss and earlier senescence, significantly limits their shelf life. In this study, we investigated the mechanistic role of modified atmosphere packaging (MAP) on the physiochemical quality, phenolic metabolism, and antioxidant potential of blackberries and raspberries during cold storage (2 ± 1 °C) for 12 and 10 days, respectively. Modified atmosphere (MA)-packed Rubus berries exhibited higher total phenolics accompanied by higher activities of shikimate dehydrogenase, and phenylalanine ammonia-lyase. Furthermore, MA-packed Rubus berries demonstrated lower hydrogen peroxide by maintaining higher catalase activity and delayed lipid peroxidation during the entire period of cold storage. Relatively higher levels of glutathione and ascorbic acid as well as the activities of enzymes involved in the ascorbate-glutathione cycle in MA-packed Rubus berries were also observed. Conversely, MAP reduced the respiration rate and weight loss while maintaining higher postharvest quality attributes in raspberries and blackberries than control fruit. In conclusion, MAP is an effective method for extending the cold storage life and maintaining the quality of Rubus berries.