Development of an Instrument for Measurement of Thermal Conductivity and Thermal Diffusivity of Tropical Fruit Juice (original) (raw)
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Journal of Food Process Engineering, 2006
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International Journal of Food Engineering, 2009
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Journal of the Science of Food and Agriculture, 1999
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In this research, 10 kinds of botanical beverages, concentrated juices and purees of orange and pineapple were heated applying a static ohmic heating system. The objectives were (1) to develop the mathematical models for predicting the temperature changes of these samples during ohmic heating and (2) to compare between the qualities of ohmically-heated and conventionally-heated specimens. The results indicated that the mathematical models can precisely predict the temperature variations of the concentrated purees during ohmic heating although the heat losses to the surroundings and evaporated moisture are neglected. However, the temperature estimation of botanical beverages and concentrated juices were more accurate if the heat losses to the surroundings and evaporated moisture were included in the mathematical models. Furthermore, at the same heating rate the ohmic and conventional heating methods resulted in the insignificant difference in the sensorial qualities and remaining vitamin C contents of orange and pineapple juices.