A Review of Different Drying Technique of Freshly Harvested Maize Cobs

Abstract

At the time of harvesting, maize contains moisture of about 20 – 25% and, in this moisture level, the growth of mould & fungi increases which can cause damage to the grains. The moisture content of 11.8-13%, which is suitable for safe storage, must be achieved after the drying of maize. The passive solar dryer dries grain faster than the open conventional system. It took 2 days for the maize cobs to dry with a stabilized weight of moisture from 30.3 g to 24.3 g using the constructed passive solar dryer, whereas, it took 6 days to dry the same cobs to 25.4 g under the open conventional sun drying system. Maize cobs in the solar dryer looked cleaner compared with the sun drying. The drying of maize to safe moisture content of 14% for 5 days and 6h respectively when taken for drying on bare ground and by the biomass¬ heated natural convection dryer, it reduced the drying time and greatly improved the quality of the grain during storage. The passive universal dryer reduced the moisture content of fresh maize up to the safe storage level 12% (wb) in 12 h resulting in 98% viability of dried maize. Passive universal dried product was more acceptable, neat and spores less food materials, as compared with the sun dried products. The main aim of this research was to review the various types of dryers and drying methods used in drying of maize cobs