Effect of Process Variables on Gas Release from Free and Latex-Coated Calcium Alginate Beads

Volatile compounds are emitted as gases from certain solids or liquids. These compounds are important in agricultural production as plant growth enhancers, fruit ripening agents, and pesticides. Ca-alginate beads have been used to control the release of volatile compounds. This study aims to investigate the effects of process variables on gas release (carbon dioxide gas was used as a model gas) from free and latex-coated floating calcium alginate beads. Floating beads were prepared from a sodium alginate solution containing calcium carbonate (CaCO3) as a gas-forming agent. The resulting solution was then extruded into a calcium chloride (CaCl2) solution and coated with latex solution. The effect of alginate concentration and extrusion tip diameter on beads size was investigated. The results indicated that increasing alginate concentrations and the extrusion tip diameter led to the formation of larger beads. Moreover, the gas (CO2) released from free and latex-coated beads was studied. It was observed that the release rate of CO2 from free-floating beads increased with the increased extrusion tip diameter but decreased with increasing alginate concentration. Instead, applying latex coating on floating calcium alginate beads could provide the controlled release of CO2.