earticle

영어

CO2 concentration in kimchi package has emerged recently as a potential index of product ripening to be monitored or sensed in intelligent packaging. Considering that addition of CO2 absorber into the flexible kimchi package changes behavior of its CO2 concentration, ripening of kimchi in total acidity, package CO2 concentration in partial pressure (PCO2) and package volume at 10oC were estimated by mathematical model for two size packages included with different CO2 absorbers. In small size package containing 0.5 kg of kimchi, relatively less gas permeable low density polyethylene (LDPE) sachet of the absorber was found to give rise of PCO2 linearly correlated with acidity at acceptable conditions of absorber amount and size. The levels of PCO2 at optimum ripening were different with absorber amount. However, highly gas permeable microporous spunbonded film (Tyvek) sachet did not show the linear relationship except a condition of 1.5 g of CO2 absorbent. In large size package containing 2.0 kg, absorber sachets of LDPE and Tyvek could give the linear relationship between product acidity and package PCO2 but at different levels (PCO2 of package with LDPE sachet: 0.46~0.79 bar, PCO2 of package with Tyvek sachet: 0.00~0.75 bar). The PCO2 at optimal ripening was found to be less variable with LDPE sachets than with Tyvek ones. Use of package CO2 concentration as an indicator of kimchi ripening was shown to be possible on the limited conditions where the linear relationship between them is established or confirmed.