Ohmic Heating Characteristics of Water Chestnut Juice and the Effect of Ohmic Heating on Its Clarity

The water chestnut juice was an important processed product of water chestnuts,but its poor clarification had strong negative effect on the quality of products. To obtain the ohmic heating properties of water chestnut juice,the samples were treated using a self-made ohmic heating device,and the effect of ohmic heating on the clarification of the juice was analyzed. The results showed that the conductivity of water chestnut juice increased with the increment of temperature and electric field frequency. The temperature of water chestnut juice had a linear relationship with time under low frequency and low electric field strength,and exponential relationship under high frequency and high electric field strength. On the same electric field intensity,the conductivity of water chestnut juice increased with the increment of heating frequency,and the conductivity under the 200 and 400 Hz were twice as much as it under the 50 Hz. The capacitive reactance value mainly fluctuated between -5 and 0 Ω,and the electric field strength had little influence on it (p>0.05). The electric potential value declined a half compared with the primary the electric potential value,the stability of the particles reduced,making it easier to clarify the juice. Above all,ohmic heating had a certain improvement on the clarification of the water chestnut juice.