(515b) Characteristics of Carbon Dioxide Adsorption on Food Grains at Different Temperature and Moisture Contents

Grain storage in an inert atmosphere seeks to avoid or lower the changes, which must be caused by the presence of oxygen. Normally the gases used for this purpose are either carbon dioxide or nitrogen. The distinctive feature of the action of carbon dioxide (CO2) is its sterilization effect on the growth of microbes and fungi etc. Even when there is a high level of oxygen remaining in the vessel, a higher concentration of CO2 effectively prevents pest growth while nitrogen can not do so .This is favorable characteristic for the practical use of CO2 in the prolonged storage of grain because the risk of contamination of oxygen into the storage vessel can not be eliminated. The current research aimed at measuring CO2 adsorption on different grains at various temperature and moisture contents .The adsorption of CO2 by various food grain took place in a significant amount and also it was determined that the adsorbed CO2 was released completely when grain was allowed to stand in air. Thick steel walled (100 cc) metallic high-pressure reactor was specially designed to study the adsorption and desorption characteristics and also to quantify sorption. The experiments were conducted using premium basmati rice , commercial grade basmati rice (polished) and paddy at three different temperature conditions 26° C , 35° C and 40° C and three different moisture contents 5 %, 10 % and 15 % . The rate of uptake of CO2 by three rice varieties was studied, dry basis during 120 h of exposure at three temperatures (25, 35 and 40° C) and at 25° C with the different rice varieties at three moisture contents ( 5%, 10% and 15 %). The cumulative CO2 adsorbed at 120 h exposure to 100% CO2 at three temperatures and three moisture content were used to establish the relation and effect of temperature and moisture content on adsorption of grain.