Antibacterial Efficacy of Chard and Arugula as Natural Nitrite Alternatives against Staphylococcus aureus, Listeria monocytogenes and Clostridium perfringens in Basterma

This study investigated the impact of partial nitrite replacement with natural plant extracts on the sensory quality and microbiological safety of basterma during 90 days of refrigerated storage. Three groups of basterma were evaluated: G1 (control, 100 ppm nitrite), G2 (50 ppm nitrite + 50 ppm arugula extract), and G3 (50 ppm nitrite + 50 ppm chard extract). The other three groups (G4, G5 and G6) were contaminated separately with Staphylococcus aureus, Listeria monocytogenes, and Clostridium perfringens (5log cfu/g) to assess antimicrobial efficacy. Sensory evaluation was conducted at intervals throughout the 90-days storage period G1 consistently maintained high sensory quality throughout the storage period. G2, incorporating arugula extract, showed a moderate decline in sensory attributes but remained generally acceptable up to 49 days. While G3 experienced rapid and severe sensory deterioration, developing strong off-odors and off-flavors, rendering it unfit for consumption by day 60. Microbiologically, all three inoculated pathogens (Staph. aureus, L. monocytogenes, and Clostridium perfringens) below detection limit from all treated samples by the 7th day of storage. Combining sensory and microbiological findings, the basterma samples from all groups were deemed fit for consumption until the 49th day of cold storage. Then, the reappearance of pathogens by Day 60, coupled with significant sensory degradation (mostly in G3), indicated that the products became unfit for consumption by the 60th day of storage. This research affirms that arugula extract is a more promising partial nitrite replacer than chard extract for maintaining basterma quality and safety during extended refrigerated storage.