Application of Physical Gas Absorbers in Manipulating the CO₂ Pressure of Kimchi Package

Physical gas absorption and release of activated carbon or zeolite were used to attain the desired CO₂ concentration profile inside a package of kimchi for its dynamic storage and consumption environment. The CO₂ adsorption/desorption behavior of different combinations of physical scavengers in the microporous Tyvek sachet was measured at 0, 10 and 20 °C. A combination of highly permeable microporous Tyvek and much less permeable nylon/polyethylene laminate was also examined as a variable to help control the access of CO₂ to the physical CO₂ absorber. The composition of the absorber and its packing density in the sachet affected the CO₂ absorption rate and capacity. Increased zeolite in the Tyvek sachet showed higher CO₂ absorption followed by higher CO₂ release concomitant with moisture sorption, while activated carbon itself had low CO₂ absorption and little subsequent CO₂ desorption. Lower temperatures increased the capacity of CO₂ absorption and release along with lower CO₂ absorption and release rates. A reduction in Tyvek area could decrease the absorption and release rates. An application of a physical CO₂ absorber to the kimchi package was tested at 10 °C to show potential for keeping the desired CO₂ pressure profile for carbonic cool flavor under tolerable pressure during storage and use. PRACTICAL APPLICATIONS: Physical carbon dioxide absorbers consisting of zeolite and activated carbon inside the gas-permeable sachet can be placed in kimchi packages for time-dependent absorption and release of carbon dioxide, which responds in harmony with the fermentation profile of kimchi. Its practical potential is both to provide a carbonic cool taste of the product and to avoid excessive overpressure in the package through its shelf life when used in kimchi packaging. Its intelligent use may resolve the problem of a dull kimchi taste, which occurs when incorporating calcium hydroxide as the chemical scavenger in the package.