Effect of ethanolic extract of Silybum marianum L. Gaertn. on lipid peroxidation inhibition and microbial count in minced beef

The present research was carried out for two main targets, the first one is phytochemical and biological screening of the aerial parts of Silybum marianum. The second one is the possibility of using Silybum marianum ethanolic extract as natural preservative for extending minced beef shelf-life during refrigeration and frozen storage. The chemical analysis of dry matter revealed that total ash content was 13.04% of D.M, crude fibers, total phenolic compounds, total flavonoids and total tannins were (24.59%, 9.16%, 0.84% and (0.08%), respectively. The highest values of antioxidant activity were recorded in ethyl acetate and ethyl alcohol 70%extacts, respectively for successive and selective solvents with values of 82.45% and 58.85% for successive solvents, 86.84% and 70.50% for selective solvents, respectively. Antimicrobial activity showed that, S. marianum L. Gaertn. had effect on gram positive, gram negative bacteria and yeast but had no effect on different strains of studied fungi. S. marianum had an influence on microorganisms growth in minced beef, the highest effect was 1.0% for 60 days (56 CFU). The most effective concentrations on lipid peroxidation prevention in minced beef were 1.5% for 3 days and 1.5 for 60 days.