Akademik Veri Yönetim Sistemi
Türk Tarım - Gıda Bilim ve Teknoloji dergisi, cilt.7, sa.11, ss.1805-1816, 2019 (Hakemli Dergi)
Dielectric properties of materials are used for evaluating their interactions with electromagneticenergy. Dielectric properties of food materials are required for various applications in food industrysuch as microwave (at 915 or 2450 MHz), radio wave (at 13.56, 27.12 or 40.68 MHz) and magneticfield processing. In order to understand the response of food materials to electromagnetic energy,dielectric parameters must be determined as a function of frequency, temperature, composition andmoisture content. In this review, the dielectric properties of different food groups were listeddepending on temperature and frequency ranges. In addition to the literature data of dielectricproperties, the penetration depths of microwave or radio wave through food groups were calculated.The effects of temperature and composition (mostly moisture content) on dielectric propertiesdepend on the type of the food and sometimes on frequency. However, the effect of frequency isconstant; increased frequency decreased dielectric constant, loss factor and penetration depth. Thelowest calculated penetration depth belonged to the fish surimi gel as 3.39 mm at microwavefrequency whereas they were high generally for fats, oily seeds and flours (max was 372602 mm forcorn flour). It appears that dielectric properties of foods should be investigated further depending onthe interactions between frequency, temperature and composition. And then, dielectric heating basedon the aim of the process can be applied accordingly. Besides, it appears that the moisture contentand especially the dipole rotation and the conductivity movements of the molecules in free watercontent of the food are some of the most critical factors influencing the dielectric properties of foodmaterials.