Effects of microwave heating on quality attributes of pineapple juice.

The effects of microwave heating on the quality attributes of pineapple juice were investigated in this study. The experiments were conducted based on the central composite design of response surface methodology to analyze the relationship of mass evaporation rate at different initial masses of pineapple juice (100–250 g) on the physiochemical properties of pineapple juice. The results showed to have significant parabolic increment, except the sugar content of pineapple juice behaved linearly with the mass evaporation rate. The diffusion of moisture was well explained by the Fick's second law. The modified Arrhenius model was used to estimate the activation energy (1.02–3.20 kW/kg). The drying model of Henderson and Pabis could fit well into the kinetic behavior of concentrating pineapple juice. The change of quality attributes, particularly browning effect and proteolytic activity could be minimized using low initial mass of juice and heated at short duration for high evaporation rate. [ABSTRACT FROM AUTHOR]