Unit I
Overview of post-harvest technology: Concept and science, production and post-harvest losses, reasons for losses, the importance of loss reduction; Water activity, water binding and its effect on enzymatic and non-enzymatic reactions and food texture, control of water activity, and moisture.
Unit II
Post-Harvest Handling operations; Cleaning: Cleaning of grains, washing of fruits and vegetables, types of cleaners, screens, types of screens, rotary screens, vibrating screens, machinery for cleaning fruits and vegetables (air cleaners, washers), cleaning efficiency, care, and maintenance; Sorting and grading: Sorting, grading, methods of grading; Grading- Size grading, color grading, specific gravity grading; screening, equipment for grading of fruits and vegetables, grading efficiency, care, and maintenance.
Unit III
Separation: Magnetic separator, destoners, electrostatic separators, pneumatic separator; Decorticating and shelling: Principles of working, design and constructional details, operating parameters, maintenance, etc. of various decorticators/dehullers/shellers, description of groundnut decorticators, maize shellers, etc.; Grain drying theory, grain dryers; Liquid dryers; Parboiling: process, changes during parboiling, parboiling methods, advantages and disadvantages of parboiling with respect to milling, nutritional and cooking quality of the grain, significance of glass transition temperature.
Unit IV
Milling: milling, polishing, grinding, milling equipment, dehusked, polishers (abrasion, friction, water jet), flour milling machines, pulse milling machines, grinders, cutting machines, oil expellers, machine efficiency, and power requirement; Materials handling: Introduction to different conveying equipment used for handling of grains, fruits, and vegetables; Scope and importance of material handling devices.
Unit V
Study of different material handling systems: Classification, principles of operation, conveyor system selection/design; Belt conveyor: Principle, characteristics, design, relationship between belt speed and width, capacity, inclined belt conveyors, idler spacing, belt tension, drive tension, belt tripper; Chain conveyor: Principle of operation, advantages, disadvantages, capacity, and speed, conveying chain; Screw conveyor: Principle of operation, capacity, power, troughs, loading and discharge, inclined and vertical screw conveyors; Bucket elevator: Principle, classification, operation, advantages, disadvantages, capacity, speed, bucket pickup, bucket discharge, relationship between belt speed, pickup and bucket discharge, buckets types; Pneumatic conveying system: Capacity and power requirement, types, air/product separators; Gravity conveyor design considerations, capacity and power requirement.