Effects of Thymus vulgaris, Zataria multiflora, Salvia verticillata, and ε-polylysine on shelf-life extension of sweet basil leaves

Abstract

ABSTRACT Due to basil’s short shelf life and the insufficient research on utilizing plant extracts and ɛ-polylysine as a natural preservative for vegetables, this research was to investigate different concentrations of plant extracts of Thymus vulgaris, Zataria multiflora, Salvia verticillata, and ε-Polylysine on increasing the shelf life of basil during cold storage at a temperature of 8°C over 12 days. All the treatments had less weight loss compared to the control group at the end of the storage period. ε-Polylysine (3 ml/L) and T. vulgaris (2 g/L) treatments effectively reduced spoilage symptoms by decreasing the activity of degrading enzymes like cellulase and polyphenol oxidase. Additionally, these treatments increased the activity of enzymes such as catalase, which inhibits the production of reactive oxygen species. By preserving phenolic compounds, antioxidant activity, ascorbic acid, and reducing microbial load, the ε-Polylysine (3 ml/L) and T. vulgaris (2 g/L) treatments extended the shelf life and quality of basil. The results indicate that using ε-Polylysine (3 ml/L) and T. vulgaris (2 g/L) treatments effectively preserved the sensory attributes of basil, including freshness, appearance, overall acceptability, and odor, throughout storage. Furthermore, these treatments reduced spoilage, extended shelf life, and improved the nutritional value of basil during storage.