Physiological effects of putrescine and modified atmosphere packaging treatments on quality, phenolic compound and biochemical stability of cape gooseberry (Physalis peruviana L.) fruit by suppressing respiration rate.

backgroundThis study investigated the effects of putrescine (Put), modified atmosphere packaging (MAP), and their combination (Put + MAP) on the physicochemical and biochemical quality of fruits during postharvest storage. The fruits were stored for 30 days, and changes in weight loss, decay rate, respiration rate, organic acids, vitamin C, sugars, and phenolic compounds were examined throughout the storage period.

resultsSignificant quality losses were observed in the control group as the storage period progressed; by the end of the 30th day, weight loss and decay rate reached 7.91% and 6.69%. Conversely, the Put + MAP treatment was able to effectively suppress weight loss and decay, hence minimizing the deterioration of overall quality. Although respiration rate was high at the end of harvest, it significantly decreased towards the end of storage in the Put + MAP treatment, hence showing a substantial reduction in metabolic rates. Organic acids generally tended to decrease in concentration throughout storage; however, their levels were better maintained in the Put + MAP treatment than in the control. Citric acid content decreased to 544.74 mg 100 g⁻¹ in the control group at the end of 30 days, while it was maintained at 617.26 mg 100 g⁻¹ in the Put + MAP application. Similarly, vitamin C content decreased to 20.28 mg 100 g⁻¹ in the control group, while it was determined to be 30.83 mg 100 g⁻¹ in the Put + MAP group. Phenolic compounds were also affected by the treatments. Although phenolic acids tended to decrease in concentration throughout storage in the control treatment, their retention was significantly higher in fruits treated with putrescine, either alone or in combination with MAP. The combined Put + MAP treatment was therefore more effective in maintaining biochemical quality attributes and in slowing down the rate of postharvest senescence than the control.

conclusionAnalysis of variance showed that storage time and the “treatment × storage time” interaction were statistically significant for many parameters (mostly p ≤ 0.001). PCA, heat map, and correlation analyses revealed that Put + MAP treatment maintained the most balanced physiological profile and best preserved quality related components. In conclusion, the Put + MAP combination emerged as an effective preservation strategy that delays post-harvest quality loss.