Drying kinetics and quality characteristics of microwave-assisted hot air dried beef chips

In this study, the drying kinetics and quality characteristics of microwave-assisted hot air dried beef chips were investigated. For this purpose, beef slices were treated with spice mixture (4 g/100 g beef) and then dried with 2 different air temperature (60 and 70 degrees C) and 3 different microwave power (0, 90 and 180 W at fixed product weight). Drying process was terminated when moisture content of samples went below 15% and then drying kinetics and quality characteristics of the beef chips were analyzed. Drying time of beef chips reduced due to the increase in the microwave power and temperature whereas Page model was the most suitable model for identifying drying kinetics. It was also noted that average moisture content of microwave-assisted hot air dried beef chips was 12.8% (dry basis), water activity (a(w)) value was 0.70, pH value was 5.8 and thiobarbituric acid reactive substances (TBARS) value was 30.48 mu mol MDA/kg. It was further found that those beef chips that were dried at high temperature (70 degrees C) and microwave power (180 W) had darker color (higher a* value) and shorter, thicker and harder (high cutting force). Moreover, it was finally noted that such fast drying samples had better microbial and sensory quality.