Mathematical Modeling of Microwave Heating of Food
MATHEMATICAL MODELLING OF MICROWAVE HEATING OF FOOD
By M . SHIVA KUMAR ( 04AG1008 ) Under the guidance of PROF. SURESH PRASAD
ABSTRACT
• The use of microwaves in the food industry is attributed to the lower time needed to increase the temperature of foodstuffs compared to the traditional heating methods.
•However, the heating is not uniform and the products show hot and cold spots.
• In order to analyze the behaviour of foods heated by microwave oven, a mathematical method was developed solving the unsteady state heat transfer differential equations.. • It takes into account variable thermal and electromagnetic properties.
•The numerical solution was developed using an implicit finite difference method in one dimensional system (slab).
• It allows predicting temperature profiles. • The model will later be validated with experiments and data on apple fruit.
ADVANTAGES OF MICROWAVE HEATING
• Does not involve a conduction or convection medium • Food material is heated directly due to agitation of the polar molecules contained – namely water • Reduced drying time • Improved final quality of the dried products • Better rehydration
DRAWBACKS OF MICROWAVE HEATING
• Inherent non-uniformity of the electromagnetic field within a Microwave cavity. • Excessive temperatures along the edges and corners of products may lead to overheating and irreversible drying-out resulting in possible scorching and development of off-flavors.
• Final product temperature in MW drying is difficult to control, compared to that in hot-air drying in which product temperature never rises beyond air temperature. • Limited amount of water is available during the final stages of drying processes, hence the material temperature can easily rise to a level that causes scorching
TEMPERATURE PROFILE PREDICTION
A mathematical model is proposed to predict temperatures during microwave food heating, taking into account thermal and dielectric properties of the food material
By M . SHIVA KUMAR ( 04AG1008 ) Under the guidance of PROF. SURESH PRASAD
ABSTRACT
• The use of microwaves in the food industry is attributed to the lower time needed to increase the temperature of foodstuffs compared to the traditional heating methods.
•However, the heating is not uniform and the products show hot and cold spots.
• In order to analyze the behaviour of foods heated by microwave oven, a mathematical method was developed solving the unsteady state heat transfer differential equations.. • It takes into account variable thermal and electromagnetic properties.
•The numerical solution was developed using an implicit finite difference method in one dimensional system (slab).
• It allows predicting temperature profiles. • The model will later be validated with experiments and data on apple fruit.
ADVANTAGES OF MICROWAVE HEATING
• Does not involve a conduction or convection medium • Food material is heated directly due to agitation of the polar molecules contained – namely water • Reduced drying time • Improved final quality of the dried products • Better rehydration
DRAWBACKS OF MICROWAVE HEATING
• Inherent non-uniformity of the electromagnetic field within a Microwave cavity. • Excessive temperatures along the edges and corners of products may lead to overheating and irreversible drying-out resulting in possible scorching and development of off-flavors.
• Final product temperature in MW drying is difficult to control, compared to that in hot-air drying in which product temperature never rises beyond air temperature. • Limited amount of water is available during the final stages of drying processes, hence the material temperature can easily rise to a level that causes scorching
TEMPERATURE PROFILE PREDICTION
A mathematical model is proposed to predict temperatures during microwave food heating, taking into account thermal and dielectric properties of the food material
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