Programmed Conditions of Supplying Carbon Dioxide to Keep its Desired Concentration in Kimchi Container

Abstract

Kimchi is a refreshing sour food which gives sour and carbonic acid taste of carbon dioxide produced during the fermentation process. So, carbon dioxide injection was tried to raise carbonic acid taste of kimchi stored in the airtight container. First, carbon dioxide injection times of a given gas supply system were determined experimentally to attain initial concentration of 80% for different solid/liquid ratios. Since carbon dioxide is dissolved in kimchi to decrease its concentration during storage, periodical carbon dioxide injection conditions were needed and determined to keep the CO2 concentration above 70%. For the initial flushing to 80% CO2 concentration in model system filled with water, the injection time ranged from 40 to 89 seconds for free volumes of 2-8 L. CO2 injection conditions for the under-ripened storage at 10C consisted of longer time at more frequent cycles for watery kimchi than for Chinese cabbage kimchi. At 0C of subsequent ripened stage storage of watery kimchi, the periodical injection at 3 hour interval was required because of continuous dissolution of carbon dioxide. However, Chinese cabbage kimchi did not require subsequent CO2 injection during the ripened state storage and needed only flushing to 80% CO2 at time of the container opening and closing. These results can be used as basic information for the programmed control of CO2 injection in the kimchi container system.