FDSC 310 Lecture 8: Postharvest technology lecture 8
10 Oct 2017
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Document Summary
General considerations: control of temperature, rh, air velocity, air composition. Simple systems: ventilated storages (potato, carrot, dry onion). Ra insulation, air circulation and ventilation, mechanical refrigeration. Insulation, air tightness, vapor barrier, precise control of temperature, rh, air composition. Important factors storage requirements differs for different commodities. Separate storage chamber for each produce is ideal but not practical. Mixed loads are common in storage, compatibility is important including ethylene production. Lowest permissible temperature (chilling injury) optimal t is produce dependent. Use q10 to estimate loss of quality. temperature fluctuation should be below 2 degrees, large fluctuations mean loss of quality. Desiccation if air is not saturated and if saturated sweating. Desiccation if wvpd is positive, condensation if wvpd is negative. Undersized: sow cooling, product warming, large temperature fluctuations. Maintain room t close to refrigeration t, allows lower fluctuations. Adequate thermal insulation prevent heat gain through walls ceiling etc.
