ANTIMCROBIAL ACTIVITY OF LICORICE (Glycyrrhiza glabra) EXTRACT AGAINEST SOME PATHOGENIC MICROORGANISMS AS A PRESERVATIVE AGENT IN MANGO NECTAR AS AN ALTERNATIVE TO SODIUM BENZOATE

Abstract

Chemical preservatives cause great concern due to their unhealthy effects, and plant extract could be used as a natural antimicrobial alternative to chemical preservatives. The objective of the present research is to investigate the use of licorice extracted using 80% ethanol solution as a natural preservative in mango nectar and its impact on the physicochemical and sensory characteristics. The bioactive compounds in licorice extract and their antimicrobial activity were determined utilizing LC-MS/MS, HPLC, and disc diffusion techniques. The effect of licorice extract on mango nectar's physicochemical, sensory, and microbiological properties was examined.  The results showed that the major antimicrobial compounds in licorice extract were ellagic acid, quercetin, rutin, and catechin. The extract exhibited substantial antibacterial action, effectively suppressing the development of all tested harmful bacteria, such as Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa, except Escherichia coli, where its effect was less pronounced.  Additionally, licorice extract had comparable efficacy to mango nectar treated with sodium benzoate in reducing the overall bacterial count at 1% concentration. Furthermore, it fully suppressed fungal growth at all concentrations for seven days. The physicochemical and sensory properties of the mango nectar treated with licorice extract varied negligently compared to sodium benzoate treatments. Licorice extract is an effective natural preservative for mango nectar, showing comparable efficacy to sodium benzoate in controlling microbial growth while maintaining the physicochemical and sensory properties of the juice.