Stability of dried pumpkin snacks packed in bio-polymeric films through accelerated shelf-life testing

This research evaluated the storage characteristics of dried pumpkin packed in two different films: polylactic acid (PLA) and polyethylene (PE) by accelerated shelf-life testing (ASLT) at three storage temperatures: 30, 40, and 50 °C. Weight loss, pH, water activity, color, and total microbial count of the samples were monitored at fixed times during the experiments. After 2 days of storage at 50 °C, the weight loss for the PLA and PE packaging reached its maximum value at 9.15 ± 0.8% and 6.53 ± 1.6%, respectively. The microbiological results demonstrated that, with a total plate count of fewer than 4 log CFU/g, the dried pumpkin samples did not degrade while being stored at different temperatures. Bioactive compound content (total polyphenols, ascorbic acid content, and carotenoid content) and antioxidant activity were determined at the end of storage, and they significantly changed with higher temperatures. The largest total polyphenols losses were observed for samples PLA 40 °C and PLA 50 °C (40%) and samples PE 50 °C (55%). For both packaging under the same storage conditions, antioxidant activity and ascorbic acid concentration likewise showed a similar pattern. The color changes observed during the storage were described by the non-enzymatic browning process using a pseudo-first-order reaction in terms of Chroma. The activation energy in terms of Q10 (defined as the ratio of the rate constants when the temperature is raised by 10 °C) and the storage time at 25 °C were determined. The results showed that PLA film is an appropriate packaging for preserving the physico-chemical properties of dried pumpkin snacks.