Effect of microwave cooking on foodborne pathogens in fish

Abstract

Considering the popular use of microwave ovens to prepare foods, inhibitory effect of microwave cooking on foodborne pathogens was studied. Whiting and salmon blocks were inoculated either with E. coli O157:H7, Staphylococcus aureus or Listeria monocytogenes, then cooked in microwave oven to the internal temperatures of 50 and 70°C. Cooking of fish fillets to both internal temperatures resulted in approximately 4 log cfu/cm2 reductions in E. coli O157:H7 population. After cooking to the internal temperatures of 50°C S. aureus counts reduced by 2.78 and 1.06 log cfu/cm2 on whiting and salmon fillets, respectively. L. monocytogenes counts reduced by 1.70 and 0.14 log cfu/cm2 on whiting and salmon fillets, respectively, cooked to 50°C. S. aureus and L. monocytogenes counts reduced below detectable level (2 log cfu/cm2) when cooked to 70°C. The results suggest that internal temperature should be higher than 70°C during microwave cooking to destroy completely these pathogens. Practical applications This research shows that pathogens of Listeria monocytogenes, Staphylococcus aureus and E. coli O157: H7 cannot be completely inhibited by microwaving at 50 and 70°C (internal temperatures) in both fish species. The findings revealed that using a microwave oven to cook fish could be a problem regarding pathogen inactivation in terms of food safety and human health. The study may also help microwave oven producers and caterers to prepare the manufacturer's recommendations, and to determine CCPs in HACCP plans.

Mild processing of seafood—A review

“…In contrast, Aeromonas hydrophila was reduced by 5 log CFU/g. To the best of our knowledge, only one study in the past 5 years has investigated the specific effect of MW on foodborne pathogens in fish products concluding that even though MW had a significant effect on the microbial inactivation of L. monocytogenes , Staphylococcus aureus , and E. coli O157:H7, a treatment above 70°C core temperature was needed to ensure complete destruction of these pathogens (Ulusoy et al., 2019).…”

Impact of different microwave treatments on food texture

“…This can be risky for the consumer because they often decide to eat any food based on its appearance. In addition, strategies (turntables, mod stirrers, or moving the product) to minimize problems in ensuring heating are not always sufficient (Fryer & Robbins, 2005; Ulusoy, Üçok‐Alakavuk, Mol, & Coşansu, 2019). Excessive heating speed, overheating of the edge, wet texture, and lack of browning are other microwave issues.…”

“…turntables, mod stirrers, or moving the product) to minimize problems in ensuring heating are not always sufficient(Fryer & Robbins, 2005;Ulusoy, Üçok-Alakavuk, Mol, & Cos ¸ansu, 2019). Excessive heating speed, overheating of the edge, wet texture, and lack of browning are other microwave issues.Microwave cooking leads to cooking defects and some adverse effects on the structural properties by changing the quality parameters of the product (Barbosa-Cánovas, Medina-Meza, Cando gan, & Bermudez-Aguirre, 2014; Tas ¸kıran, Olum, & Cando gan, 2019).…”