Impact of microwave heating on product safety and quality in meatballs

The effects of microwave heating at different processing time and power levels (360 W, 600 W and 900 W) on Salmonella Typhimurium , Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in Turkish type meatballs were evaluated. Besides, the changes in the textural and sensorial properties of meatballs were determined to reveal the cooking time and temperatures that would make the product safety without affecting the consumer preferences. In this direction, the experimentally contaminated meatballs were subjected to microwave heating at low, medium and high power levels for different processing times and analysed for the survival of the relevant pathogenic bacteria. The total aerobic bacteria count in meatballs could be reduced approximately 3 - 4 log CFU/g by medium and high microwave powers, whereas 5 - 7 log CFU/g inhibition was obtained in meatballs inoculated with pathogens. The increase in power level together with the increasing process time resulted in a decrease in the counts of bacteria and an undesirable effect on the textural and sensorial qualities of meatballs. Microwave heating at medium and high power levels as from 3 min, caused excessive drying and blackening of the product, making it difficult to consume due to crust formation. Consequently, to achieve optimal acceptability of the product by consumers, meatballs should be heated with a microwave power of 600 W and 900 W for 3 min.