Abstract
The antimicrobical and antiviral effects of native soy lecithin, quercetin and quercetin-enriched lecithin formulations were studied. The preparation of quercetin-enriched lecithin was described for the first time. In general, antimicrobial and antiviral activities of quercetin-enriched lecithin formulations were found to be better than individual lecithin or quercetin, most likely as a consequence of synergism between polar lipids and quercetin. Quercetin-enriched lecithin formulations exhibited strong antimicrobial action in comparison with native lecithin and quercetin. Increases in the concentration of quercetin in the formulation resulted in an increase in its antimicrobial activities. In addition, quercetin-enriched lecithin formulation (1: 99, w/w) also showed high antibacterial activity against gram-positive bacteria with minimum inhibitory concentration between 750 and 1,000 mu g/mL. Quercetin-enriched lecithin formulation (3: 97 w/w) had a drastic effect on the biosynthesis of protein in cells of Bacillus subtilis, but the effect was slightly noted on the biosynthesis of DNA and RNA. The results are of great importance for improving the biological activity, functionality and health impact of commercial lecithin that could be applied in different food and pharmaceutical applications.