Enhancing Ground Beef Shelf Life Using Psidium guajava Leaf and Oliveria decumbens Essential Oils: Antimicrobial, Antioxidant, and Quality Preservation Effe

ABSTRACT

This study evaluated guava leaf essential oil (GL‐EO) and flowers and seeds of Oliveria decumbens essential oil ( Od ‐EO) for their antimicrobial, antioxidant and sensory effects in ground beef. The essential oils were applied individually and in combination to ground beef samples (control, GL‐EO, Od ‐EO, and GL‐EO +  Od ‐EO), which were packaged in sterile polyethylene zip‐lock bags and stored at 4°C for 10 days. In vitro analyses revealed concentration‐dependent antimicrobial activity against both Gram‐positive and Gram‐negative pathogens, with Od ‐EO showing superior efficacy attributed to its high content of thymol and carvacrol. Antioxidant assays demonstrated strong radical scavenging capacity for both oils, with Od ‐EO exhibiting 1.5‐fold higher activity in 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assays compared to GL‐EO ( p  < 0.05). In ground beef applications, microbiological analyses (total mesophilic/psychrotrophic counts, coliforms and fungi) showed that both oils significantly ( p  < 0.05) inhibited microbial growth, with the GL‐EO +  Od ‐EO combination exhibiting notable preservative effects (approximately 2 log CFU/g reduction compared to controls). Chemical analyses revealed 45% lower thiobarbituric acid reactive substances (TBARS) values in treated samples, total volatile basic nitrogen (TVB‐N) levels maintained at < 20 mg/100 g throughout and improved storage, pH stability (6.3–6.5 vs. 6.8 in controls) ( p  < 0.05). Sensory evaluation indicated that the combined treatment received the highest acceptability scores for color, odor, texture, and overall acceptability, without negative sensory impact. The GL‐EO treatment also achieved high scores in preserving odor and color. These effects are associated with the oils' bioactive compounds (thymol, carvacrol, limonene, β‐caryophyllene). These results suggest that these essential oils, particularly in combination, can serve as effective natural preservatives, extending shelf‐life while maintaining quality. All treatments significantly extended shelf‐life by 4 days compared to control ( p  < 0.05).