Mechanisms of carbon dioxide gas adsorption by grains and its application to skin-packaging

Abstract

The data obtained with warburg's manometry have revealed that grains such as rice, wheat, corn, peanuts, soybeans, red beans, sesame seeds, and coffee beans and their flours can adsorb a significant amount of CO2 gas. The mechanism of CO2 adsorption phenomenon was examined. The results obtained are summarized as follows: 1. Solubility of CO2 gas into the moisture and lipids of the grains is assumed to have a minor effect on this adsorption phenomenon. 2. Diffusion of CO2 gas into the grain is important in this phenomenon. This adsorption phenomenon is very similar to that observed in sorption of gases by charcoal and silica gel, which sorbe gases into their many pores. The CO2 sorbed by the porous tissues of the grains is considered to remain in solid solution. 3. The amount of CO2 gas adsorbed by brown rice under varying partial pressures follows the classic sorption isoterm of Freundlich. 4. Microautoradiographic experiments show that the radioactivity of 14CO2 appears to be uniformly distributed throughout the tissues of germ and cotyledon. The adsorption phenomenon has led to the development of a new technique for skin-packaging, the Carbon Dioxide Exchange Method (CEM). This method and two modifications are explained. The merit and usefulness of these techniques are discussed. © 1973, Center for Academic Publications Japan. All rights reserved.