Physio-chemical changes during post harvest handling of onion (Allium cepa L.) - A review

Harvested onion bulbs under goes several physio-chemical changes like increase in respiration, physiological loss in weight (PLW), rotting and sprouting. Chemical changes in stored of onions include dry matter content, pungency, abscisic acid and fructans concentration. The seasonal differences were observed in the weight of the onions, dry matter content, glucose and total carbohydrates. Even some of the pre-harvest cultural practices like nutrition, maturity, growth regulator spraying etc and also post harvest curing would extend shelf life of onion bulbs. Onion storage in ventilation condition is satisfactory when the temperature is maintained between 25°C to 30°C with a relative humidity 65 to 70 per cent.