Synergistic Utilization of ε-Polylysine and p-Coumaric Acid as Natural Preservatives for Enhancing the Shelf Life of Fresh-Cut Green Bell Peppers

Abstract

The utilization of natural preservatives presents a promising avenue for mitigating the spoilage of fresh-cut fruits and vegetables induced by microorganisms, enzymatic browning, and water loss. We have developed an innovative method for preserving fresh-cut green peppers using the combined effects of ε-polylysine (ε-PL) and p-Coumaric acid (p-CA). Through concentration screening experiments, we determined that the optimal concentrations of ε-PL and p-CA were 25 mg/L and 10 mg/L, respectively (ε-p-CA). Treatment with ε-p-CA significantly improved the quality of fresh-cut green peppers. It effectively reduced hardness and weight loss, preserving the texture and appearance of the peppers. Furthermore, ε-p-CA treatment delayed the increase in respiratory rate, electrolyte leakage, and ethylene production, thereby maintaining the structural integrity. Meanwhile, ε-p-CA treatment effectively inhibited the malondialdehyde (MDA) content increase and maintained DPPH radical scavenging activity. The microbial analysis demonstrated the ε-p-CA-treated peppers also showed lower total bacterial, mold, and yeast counts, which prolonged the freshness of fresh-cut peppers. In addition, ε-p-CA treatment improved the retention of phenolics and vitamin C without significantly affecting the color and soluble sugar content of green peppers. Overall, the ε-p-CA treatment showed promise as a natural preservative for extending the shelf life of fresh-cut green peppers.

Characterization and Antioxidant and Antibacterial Activities of Carboxymethylated Tamarind Seed Polysaccharide Composite Films Incorporated with ε-Polylysine and Their Application in Fresh-Cut Green Bell Pepper Preservation

“…The CTPε 2 group demonstrated the least ascorbic acid loss, at only 12.41%, and the control group, at 25.83%. The reduction in ascorbic acid content not only significantly impacts the nutritional composition of bell pepper slices but also indirectly indicates the weakening defense capability of bell pepper slices themselves . By day 10, the CTPε 2 group maintained a higher level of ascorbic acid content at (70.38 ± 0.67) mg/100 g, while the control group had only (59.51 ± 2.09) mg/100 g. The research findings suggest that the CTPε 2 coating effectively inhibits the loss of ascorbic acid in freshly cut bell peppers.…”

“…Starting from day 2, the control group showed a more pronounced decline in hardness, while the CTP group and the CTPε 2 group experienced only a slight decrease. The rapid decline in hardness of the control group can be attributed, on the one hand, to the rapid loss of nutrients and moisture in green bell pepper slices due to cutting-induced stress and, on the other hand, to microbial invasion, further depleting nutrients and leading to the breakdown of tissue structure . On day 10, the hardness of the CTPε 2 group decreased from 408.16 ± 17.48 g to 289.49 ± 20.92 g, while the control group’s hardness decreased from 402.14 ± 13.48 g to 212.07 ± 22.78 g. These results indicate that CTPε 2 effectively delayed the decline in hardness of fresh-cut green bell pepper slices, aligning with the observed weight loss metrics.…”

“…plus SMS UK). 12 The P2 probe was employed at a testing speed of 1 mm/s to perform puncture tests within the pepper skin with a strain set at 80%. Each green pepper slice was randomly tested five times, and a total of 30 measurements were conducted for each sample group.…”

“…11 However, these products are more susceptible to spoilage and deterioration compared to their unprocessed counterparts, leading to a shortened shelf life. 12 Therefore, the development of new preservation materials and technologies to solve the existing problems has become the primary task of relevant researchers. Simultaneously, we also pay attention to the application prospect of the coating preservation technology for preserving fresh-cut agricultural products.…”

“…The segment of fresh-cut fruits and vegetables has rapidly expanded in the last decades in line with socio-cultural changes increasingly demanding ready-to-eat foods . However, these products are more susceptible to spoilage and deterioration compared to their unprocessed counterparts, leading to a shortened shelf life . Therefore, the development of new preservation materials and technologies to solve the existing problems has become the primary task of relevant researchers.…”