Antimicrobial and antioxidant activities of natural extracts in vitro and in ground beef

• Published in: Journal of food protection 2004, Vol.67 (1), p.148-155
• Main Authors: JUHEE AHN, GRÜN, Ingolf U, MUSTAPHA, Azlin
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cattle; Colony Count, Microbial; Color; Dose-Response Relationship, Drug; Escherichia coli; Escherichia coli O157 - drug effects; Escherichia coli O157 - growth & development; Flavonoids - pharmacology; Food industries; Food Microbiology; Food Preservation; Fundamental and applied biological sciences. Psychology; Lipid Peroxidation - drug effects; Listeria monocytogenes - drug effects; Listeria monocytogenes - growth & development; Meat and meat product industries; Meat Products - microbiology; Meat Products - standards; Microbial Sensitivity Tests; Oxidation-Reduction; Plant Extracts - pharmacology; Salmonella typhimurium - drug effects; Salmonella typhimurium - growth & development; Thiobarbituric Acid Reactive Substances - analysis
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X-67.1.148

Inhibition of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes by grape seed extract (ActiVin) and pine bark extract (Pycnogenol) and the effect of these natural extracts on the oxidative stability of raw ground beef were studied. In an agar dilution test, the MICs of ActiVin and Pycnogenol were determined to be 4.0 mg/ml for 4.43 log CFU per plate of E. coli O157:H7 and 4.0 mg/ml for 4.38 log CFU per plate of L. monocytogenes. In an inhibition curve test, populations of E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes fell to below the detection limit (10 CFU/ml) after 16 h of incubation. The numbers of E. coli O157:H7, L. monocytogenes, and Salmonella Typhimurium declined by 1.08, 1.24, and 1.33 log CFU/g, respectively, in raw ground beef treated with 1% Pycnogenol after 9 days of refrigerated storage. ActiVin (1%) and oleoresin rosemary (1%) resulted in an approximately 1-log CFU/g reduction in the populations of all three pathogens after 9 days. The addition of 1% ActiVin and Pycnogenol contributed to the maintenance of an acidic pH of 5.80 and 5.58, respectively, in raw ground beef. Compared to the control, all treatments increased in L* (lightness), with the exception of ActiVin. ActiVin and oleoresin rosemary had the highest a* (redness) and b* (yellowness) values, respectively. ActiVin most effectively retarded lipid oxidation, followed by Pycnogenol. The results suggest that these natural extracts have potential to be used with other preservative methods to reduce pathogenic numbers, lipid oxidation, and color degradation in ground beef.