IIT Kharagpur crop production technology syllabus
Thermal Operations in Food Processing
3 – 0 – 0 : 3 Credits Prerequsites: None
Overview of thermal operations carried out in dairy and food processing.
Pasteurization and Sterilization: microbial destruction in batch and
continuous sterilization; kinetics of loss of nutrients in sterilization; UHT
processing; action of chemicals on death kinetics of microbes; aseptic
packaging; irradiation and microwave processing of foods; Effects of heat,
acid and short wave electromagnetic radiation on kinetics of enzyme
Crystallization and Freezing: Plank’s law and estimation of freezing time of
foods; equipment used for freezing water in food for production of crystalline
foods, e.g. sucrose and lactose; freeze concentration of liquid food.
Concentration and Evaporation: Concentration of liquid foods in batch and
continuous type evaporators; heat and energy balance in multiple effect
evaporators; design of calendria in the evaporators, falling and rising film
evaporators; mechanical and thermal vapour recompression systems. Water Relation to Foods: roles of water and activity in foods; control of
water activity by addition of solute and moisture removal; measurement of
water activity; different models of sorption isotherms, their limitations and
applicability, prediction and moderation of water activity of foods.
Drying of Foods: various mechanisms of moisture removal in solid and liquid
foods during drying; properties of air-water vapour mixture; drying
operations based on conduction, convection and radiation heat transfer;
spray, freeze, roller, tray and through-flow drying operations.