In this study the effect of high power ultrasound in degradation of ascorbic acid (Vitamin C) in fresh orange juice was investigated. Fresh orange juice was sonicated at various temperatures and acoustic amplitudes for different times at the constant frequency of 30 kHz. Then ascorbic acid was measured. The results showed that ultrasound at the high temperature, had a significant effect on vitamin C. Degradation of vitamin C was found to follow first order kinetics. It was also demonstrated that the efficiency of vitamin C increased with decreasing temperature. This paper will also present how the thermodynamic parameters of ΔS# and ΔH# changed with acoustic amplitude.

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