P-022. Antibacterial Effect of Peanut Skin Polyphenols on Raw Ground Beef Patties

J. Yu, M. Ahmedna, I. Goktepe;
North Carolina A&T State Univ., Greensboro, NC.

The growth of pathogenic bacteria in raw meat is a major cause of meat quality deteriorations and food poisoning. Common meat preservatives such as potassium nitrite and sulfites have been linked to potential health problems. Therefore, there is need for effective and safe natural food preservatives. The objective of this study was to explore the potential of crude peanut skin extract (PSE) as antimicrobial preservative in fresh ground beef. Ground beef was mixed with sterile PSE at levels of 0.1, 0.2, 0.4, 0.6, 0.8 or 1.0%. Kanamycin at 0.02% served as positive control. Untreated meat was used as negative control. Meat samples were packed in autoclaved plastic boxes then stored at 4°C for 12 days. Samples were evaluated every three days for color and total aerobic bacteria count. The most effective PSE dosage was selected and mixed with ground beef. The mixture was then split into 5 portions which were spiked with 103 cfu/g meat of Salmonella typhimurim, Staphylococcus aureus, L. monocytogenes or E.Coli, respectively, or sterile DI water (control). Spiked ground beef samples were packed and stored as described above. Samples were monitored every 3 days for pathogen growth using selective media. Results showed a 50% inhibition of total aerobic bacterial growth in ground beef containing 0.1% PSE. At 1.0% PSE, the bacterial inhibition rate reached 85-99%. Meat samples containing PSE retained more of the fresh red color compared to negative control, although a brownish color was observed upon mixing meat with high level of PSE. Significant inhibition of pathogens was also observed at 0.2% PSE and higher. This study showed that PSE exhibited significant antibacterial effect in raw ground beef. Our previous research has demonstrated that PSE also inhibited lipid oxidation in cooked ground beef, Thus, PSE has the potential to be used as natural meat preservative.