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MICROWAVE APPLICATIONS IN FOOD INDUSTRIES
K. SOWJANYA
1
& A. ASHOK KUMAR
2
1
Department of Food Science and Technology, CFST, Angrau, Hyderabad, India
2
Department of Food Engineering, CFST, Angrau, Hyderabad, India
ABSTRACT
Microwave heating is a process of heating technique, where heating causes the electric field to polarize the
charges in the material by two mechanisms namely polarization and conduction. Microwave frequencies have very short
wave lengths (33.3 cm at 900 MHz, 12.2 cm at 2450 MHz). This process is based on the ability of a particular substance
to absorb microwave energy and effectively convert the electromagnetic energy to heat. Due to mechanical oscillation, the
frictional forces within the molecules cause heat to be de
veloped due to the motion of dipoles. Microwave heating includes induction, radio frequency, direct resistance
or infra-red heating. Microwaves have many advantages in food processing such as drying, tempering, blanching,
cooking, pasteurization, sterilization, and baking. When compared with convectional heating methods, microwave
heating has considerable advantages, high reliability, especially with regard to energy efficiency, most efficient in drying
within the falling rate period, puffing of a material in case of doughnuts by internal pressure. During microwave heating,
heat is transferred from the surface of food to the interior by convection and conduction. By using microwave heating
processing of chunks of meat, sardines, and skinless frankfurters can be done. Microwave bread pasteurization is one of
the processes which enhances the destruction of micro organisms and heat liable spores during cooling, slicing, and
packaging operation. The present study involves microwave applications in different food processing operations.
KEYWORDS: Microwave, Induction, Resistance, Infra-Red, Electromagnetic Spectrum & Etc
Received: Jun 08, 2017; Accepted: Jun 28, 2017; Published: Jul 12, 2017; Paper Id: IJIETAUG20171
INTRODUCTION
Nowadays, the foods available in the market are produced using conventional thermal processing. The
microwave processed foods are shelf stable and have good qualitative traits than foods processed using other
conventional thermal processing. The microwave energy has been in industrial processing for many years. This
technique was originally conceived about forty years ago. Its adoption against conventional heating methods has
been special advantage such as faster throughputs energy savings and quality improvement. The microwave system
is composed of magnetron, set- up transformer, oven cavity, wave guide, applicator and a sample to be processed.
Microwave frequencies above 500 MHz wired circuits cannot be used where we can observe in the case of radio
frequency heating, and the power is transferred to applicator containing the material to be processed in waveguides.
In modern industrial microwave heating, systems are used for a diversity of processes in the food industry,
tempering, thawing, continuous baking, vacuum drying, pasteurization and sterilization. The overall efficiency of
microwave heating systems is usually very high, because of high power magnetrons at the rate of 85% at 900 MHz,
80% at 2450MHz.
Original Article
International Journal of Industrial Engineering
& Technology (IJIET)
ISSN (P): 2277-4769; ISSN (E): 2278-9456
Vol. 7, Issue 1, Aug 2017, 1-6
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