Antimicrobial properties of sage (Salvia macrosiphon ) seed gum and egg white via Maillard reaction

Background and Aim : Lysozyme could be considered as well-known antibacterial egg white protein, however, its antibacterial activity is mostly limited to gram-positive bacteria. Maillard type covalent conjugation with polysaccharides could be used as suitable method for improvement antibacterial activity of proteins. Sage seeds are traditionally used for antimicrobial and therapeutic effects. So the aim of this study was to investigate the antimicrobial effect of egg white protein (EWP) conjugation with sage seed gum (SSG) via Maillard reaction. Methods : EWP powder and SSG powder were dispersed in deionized water (۱:۲), magnet stirred freeze dried, ground and sieved to obtain uniform particles. Powder was placed in a desiccator with relative humidity of ۷۹% and incubated at ۶۰ ˚for ۰, ۳, ۵, ۷ and ۱۰ days. Antibacterial activity of conjugated powders was checked by disk diffusion method on Mueller Hinton agar against two gram-positive bacteria (Staphylococcus aurous and Bacillus cereus) and two gram-negative pathogens (E. coli and Salmonella). Results : Results showed increase in antimicrobial activity with conjugation days, so ۱۰-days conjugated samples indicated higher antimicrobial activity than other conjugates. Inhibition zone of ۱۰-days EWP-SSG conjugates on gram positive bacteria (۱۲ mm and ۲۰ mm for Bacillus cereus and staphylococcus aurous, respectively) was higher than ceftriaxone disk (۷ mm and ۱۵ mm for Bacillus cereus and staphylococcus aurous, respectively).Conclusion : Finally we can conclude Melanoidins could be formed at final stages of Maillard reaction so extending conjugation days improved antibacterial activity of conjugates. EWP-SSG conjugates could be used as suitable antibacterial agents to prolong shelf life of foods.

کلیدواژه ها:

Egg white ، Sage seed gum ، Maillard ، Conjugates ، Antimicrobial