Investigation of the effect of lavender (Lavandula angustifolia Mill.) essential oil on microbiological, physicochemical, and sensorial properties of meatballs during shelf-life, and its inhibitory effect on Escherichia coli O157:H7

Abstract

The present work aimed at investigating the effect of lavender (Lavandula angustifolia Mill.) essential oil on the microbiological, physicochemical, and sensorial properties of meatballs, and elucidating its antimicrobial effect on the meatballs contaminated with Escherichia coli O157:H7. The essential oil as determined via gas chromatography mass spectrometry (GC-MS) contained two major components, linalool and linalyl acetate, at 37.023 and 28.651%, respectively. The antioxidant activity test which was performed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity test, revealed that the essential oil had moderate capacity. The antibacterial activity of the essential oil was investigated against E. coli O157:H7, and the minimum inhibition concentration (MIC) was determined to be 6.4 μL/mL. Six different test groups were formed based on the concentrations of E. coli O157:H7 (0 and 108 CFU/mL) and essential oil (0, 6.4, and 12.8 μL/mL). Although essential oil had inhibitory effect against TAMB, coliforms, yeasts and moulds, Staphylococcus aureus, E. coli, and especially E. coli O157:H7 in the microbiological analyses, no effect was observed on the physicochemical properties of the meatballs. Approximately, 3 log decrease was observed in the E. coli O157:H7 levels when essential oil was added at a concentration of two-fold MIC value. It was observed that the addition of essential oil to meatballs did not increase the lipid oxidation level as much as the control group. Meatballs that contained essential oil at MIC value achieved the highest general acceptability scores at the end of their storage periods.