Comparison between conventional convective heating and microwave heating: an FTIR spectroscopy study of the effects of microwave oven cooking of bovine breast meat

The effects of microwave energy and conventional convective heating on bovine meat were studied in the mid-infrared region by FTIR spectroscopy, to highlight the differences between the two cooking methods. Samples of 100 g of bo-vine breast meat were cooked using three treatments: heating in a conventional electric oven at the temperature of 165°C for 16 min, heating in a microwave oven at 800 W for 95 sec, and heating in the same microwave oven at 650 W for 160 sec. Significant decreases in intensity of vibration bands of CH2 methylene group at 1921 and 1853 cm–1 and of the carbonyl band at 1742 cm–1 were observed after microwave heating with respect to heating in a conventional oven, showing that Maillard reaction occurs partially using microwave oven. Spectral analysis in the amide I region after mi-crowave cooking at 800 W for 95 sec showed that an increase in intensity occurred in the region from 1665 to 1690 cm-1 which can be attributed to β-turns, characteristic of disorder processes in the protein. Further analysis after micro-wave cooking at 650 W for 160 sec evidenced major increase in intensity of β-turns content and the appearance of sig-nificant increases of β-sheet component at 1635 cm-1 and 1695 cm-1 that can be attributed to aggregated β-sheets struc-tures.