Role of mid- and far-infrared for improving dehydration efficiency in beef jerky drying

Abstract

ABSTRACTThe dehydration efficiency of beef jerky dried by mid- and far-infrared drying (MFIR, MIR 2.9–3.1 µm, FIR 5.8–6.2 µm, 70°C, 1 m/s) was compared with hot air drying (HA, 70°C, 1 m/s). Results showed that the time and energy consumption, heating time to reach the targeted temperature, and activation energy of MFIR-treated samples decreased to 43, 24, 7, and 91%, respectively, when compared to HA drying. In addition, the average effective moisture diffusivity of MFIR-treated samples was 158.1% higher than that of HA. Results of low-field nuclear magnetic resonance showed that MFIR and HA induced 32.7 and 27.9% of immobilized water being shifted to free water, respectively, when water content of samples were 70%. It was assumed to be the one of the reasons for the increase in moisture diffusivity by MFIR drying. Differential scanning calorimetric and magnetic resonance imaging showed that MFIR could promote myofibrillar protein denaturation and cause more uniformed moisture distribution of samples. Our study showed that MFIR could improve dehydration efficiency of beef jerky by promoting protein denaturation, inducing the shift in immobilized water to free water, and reducing the activation energy. It was suggested that MFIR has high application potential on the dehydration of jerky.