Preservation & Storage

Keep it safe, keep it fresh. Refrigeration, drying, freezing, water activity, hurdle technology and post-harvest storage.

• Refrigeration — Refrigerators and heat pumps move heat from cold to hot using work. Learn COP, the Carnot limit, the vapour-compression cycle (evaporator, compressor, condenser, expansion valve), refrigerants and capacity in tons.
• Drying — Drying removes moisture from solids by evaporation. Learn moisture content (wet and dry basis), equilibrium and critical moisture, constant-rate and falling-rate periods, drying-time calculations, heat requirements, and dryer types (tray, rotary, spray, fluid-bed, freeze).
• Food Preservation: Freezing, Chilling, Water Activity & Hurdles — Keeping food safe and fresh longer. Learn the principles of preservation (remove, inhibit, destroy microbes; slow chemical change), chilling and cold chain, freezing (freezing point depression, ice crystal formation, Plank's freezing time, freezer burn), water activity and sorption isotherms, drying and intermediate-moisture foods, preservatives (salt, sugar, acids, chemical), smoking, fermentation, irradiation, high-pressure and other non-thermal methods, and hurdle technology — with Python for freezing time, Q₁₀ shelf-life and a hurdle check.
• Post-Harvest & Food Process Engineering — Preserving and adding value after harvest. Learn moisture content (wet and dry basis), equilibrium moisture and water activity, grain drying principles and dryer types, drying energy, cleaning, grading and milling (rice, wheat, pulses), storage structures (bags, silos, hermetic), pest control, cold chain and refrigeration load, controlled atmosphere storage, food processing operations (thermal processing, pasteurisation, extrusion), packaging and food safety — with Python for drying mass balance, energy and cooling load.