Mexican sage (Salvia officinalis) extraction using factorial design and its effect on chemical and antibacterial properties

Abstract

The essential oils (EOs) extracted by hydrodistillation (HYDRO) and steam distillation (SD) from Mexican Salvia officinalis L were analyzed for yield, chemical composition (GC-MS), particle morphology (SEM), antioxidant activity (ABTS), and antibacterial activity against Enterobacter agglomerans, Citrobacter freundii, Salmonella sp, E. coli, and Pseudomonas aeruginosa. The influence of the factors (method, quantity, and sample) was evaluated using a 23 full factorial design, Pareto chart, normal probability plot, main effects, and interaction plots in variance analysis on yield and antioxidant activity. The quantity, methods, sample, and the methods × sample and methods × quantity interactions were the most significant factors on yield (%). The sample, methods, and quantity × sample interaction were significant for antioxidant activity. EO yields were between 0.35 and 1.27 (% w/w), and the highest value was obtained by the HYDRO method using 50 g of whole sage leaves. The antioxidant activity values were in the range of 2.35 to 3.44 mg Trolox equivalent/g. Camphor, limonene, camphene, and caryophyllene were the main compounds identified. Micrographs of sage leaves showed relevant changes in the structure after extraction. The antibacterial activity was confirmed with the inhibition diameter and inhibition percentage of all bacteria, and P. aeruginosa was the most resistant bacteria. Finally, S. officinalis EO potentials can be considered an alternative natural preservative for the food and pharmaceutical industries.