The Potential Application of <i>Syzygium aromaticum</i> and <i>Cymbopogon citratus</i> Essential Oils as Natural Preservatives of Beef Patties

Abstract

The effect of essential oils from Syzygium aromaticum and Cymbopogon citratus on the lipid oxidation and microbial growth in beef patties was investigated in the present study. Essential oils were incorporated into the beef patties at 0.1% and 0.2% (w/w). The beef patties were then inoculated with cultures of E. coli and S. aureus and stored at 4°C. The control patties were processed without essential oil but inoculated with E. coli or S. aureus . The proximate composition, lipid oxidation and microbial counts were carried out after 7, 14, 21 and 28 days. Results showed that the incorporation of essential oils in beef patties did not significantly (P < 0.05) influenced the chemical composition of the beef patties but significantly (P < 0.05) reduced the TBA (Thiobarbituric acid) during storage period. The incorporation of the essential oil of S. aromaticum at 0.2% reduced the E. coli growth by 1.48 log CFU/g and that of S. aureus by 6.52 log CFU/g while the incorporation of C. citratus at 0.2% reduced the E. coli growth by 1.21 log CFU/g and that of S. aureus by 1.4 log CFU/g after 28 days of storage. The pH measurement during the storage period showed a slight drop during the first 7 days of storage and an increase during the last 21 days in all samples. The sensory test of the beef patties showed that the consumers accepted patties formulated with the two essential oils. But the one made with 0.1% essential oil of S. aromaticum was the most accepted. The analysis of the color of beef patties between 0 and 28 days of storage revealed that the incorporation of essential oils retarded the degradation of the color of patties. Results obtained in the present study indicate the possibility of exploiting Syzygium aromaticum and Cymbopogon citratus essential oils to protect beef patties against lipid oxidation and microbial growth.