Effect of lavender essential oils on sensory, chemical and microbiological quality of meatballs with Escherichia coli O157: H7

Meatballs are considered amongst most preferred products in our country. Due to uncontrolled production or inappropriate storage conditions, some food pathogens may make this product problematic for public health. Escherichia coli O157: H7 is one of the major food pathogens that may pose a risk to public health. Recently, essential oils have been the focus of scientific studies and due to their antimicrobial effects have begun to be widely used. The main reason for this was the public awareness and negative outlook of foods containing protective chemical additives. To determine the effect of the essential oil derived from lavandula angustifolia on Escherichia coli O157: H7, minimum inhibition concentration (MIC) was determined and added to 6 meatball groups at different concentrations. Mesophilic aerobes, coliforms, Escherichia coli, yeast-mold, Staphylococcus aureus and Escherichia coli O157: H7 bacterial loads were analyzed by the use of pour plate method. Staphylococcus aureus amounts were approximately the same in the first days of analysis, whereas in the last days of analysis, only 2MIC values addition of essential oil showed an important decreasement in D and F groups. When the amounts of Escherichia coli O157: H7 were examined, a decrease of about 5 logs was observed in the 2MIC essential oil containing group. During shelf life the chemical analyses of meatballs consisted on the evaluation of salt content, pH, dry matter and water activity. Dry matter content was found to decrease at the end of storage period in groups containing essential oil. During storage period no difference in water activity was observed between the groups. The meatball groups A, C and D, which did not contain Escherichia coli O157: H7, were asked to be examined in terms of color, taste, smell, texture and general acceptability as a sensory analysis on days 0th, 3rd, 7th and 12th. As for the consummability Group C containing lavender essential oils as MIC value on the 12th day of analysis was evaluated as most preferred. During storage, decrease in the smell of essential oil was noted. Obtained findings showed that the essential oil had an antimicrobial effect. The utilisation of antimicrobials such as nitrite, nitrate and sorbate over permitted limits to meat products has a negative effect on human health and this inhibits the use of these additives. Taking into account the above mentioned it is thought that combinations of lavender essential oil with different food preservatives will give better results.