Lactobacillus plantarum-Based Sustainable Biopreservation for Maintaining Postharvest Quality and Microbial Safety of Red Pepper (Capsicum annuum L.)

.This study evaluated the effects of Lactobacillus plantarum (ATCC 8014) on the postharvest quality of red pepper (Capsicum annuum L. cv. ‘Kapya’). Fruits were treated with suspensions of L. plantarum at 106 CFU mL-1 (LP1), 108 CFU mL-1 (LP2), or sterile water (control), and stored at 8 ± 1 °C and 90-95% relative humidity for 21 days. Physical quality attributes were significantly improved by bacterial treatments. By day 21, weight loss reached 15.6% in the control but was reduced to 10.5% in LP1 and 7.2% in LP2. Firmness decreased to 7.5 N in the control, while LP1 and LP2 maintained higher values of 9.2 N and 11.0 N, respectively. Color was also better preserved in treated fruits, especially under LP2, which maintained higher L*, chroma, and hue values. Chemical analyses confirmed a protective effect of L. plantarum. Ascorbic acid declined from 102 to 60 mg 100 g-1 FW in the control, whereas LP1 and LP2 retained 70 and 76 mg 100 g-1 FW, respectively. Total phenolic content decreased to 68 mg GAE 100 g⁻¹ FW in the control but remained at 76 (LP1) and 83 (LP2). Changes in soluble solids, titratable acidity, and pH were more moderate in treated fruits. The findings demonstrated that L. plantarum, particularly at higher concentrations, effectively maintained the physical, chemical, and microbiological quality of pepper during storage and can serve as a sustainable alternative to chemical preservatives.