Effect of high-pressure carbon dioxide combined with modified atmosphere packaging on the quality of fresh-cut squash...

The study evaluated the application of a novel high-pressure microbial inactivation method combining dense carbon dioxide with modified atmosphere packaging on organic fresh-cut squash (Cucurbita moschata). Approximately 4 g or 32 g of squash was packed in plastic pouches filled with CO₂ to test two different gas-to-product ratios and treated with the high-pressure method at previously optimized process conditions (45 °C, 6.0 MPa and 40 min). The products were then stored for 21 days at 4 °C and assessed for enzymatic activity, product quality, sugar content, bioaccessibility (polyphenols, DPPH antioxidant activity, and carotenoids), and sensory acceptance, with products packed in air and CO₂ serving as controls. The high-pressure treatment effectively inactivated inoculated E. coli to undetectable levels (inactivation >3.63 ± 0.53 Log CFU/g) and reduced the activity of the browning-responsible enzymes up to 50 %. During the shelf life, treated samples exhibited significantly higher scavenging activity for DPPH, ABTS, OH, O₂^-, and NO compared to non-treated samples, with minor exceptions at a high gas-to-product ratio. Additionally, treated samples showed increased levels of glucose and fructose and a comparable or higher bioaccessibility of antioxidants with respect to the products packed in air or in CO₂. Sensory evaluation indicated that the treatment enhanced color and smell appreciation among panelists, demonstrating the potential of this method to improve both safety and quality of fresh-cut squash.