Onggi's permeability to carbon dioxide accelerates kimchi fermentation

Area of Science:

• Food science and microbiology
• Materials science and engineering
• Traditional Korean culinary practices

Background:

• Traditional Korean fermented foods utilize porous earthenware vessels called onggi.
• The porous nature of onggi is believed to support lactic acid bacteria growth, but the mechanisms are not fully understood.
• Lactic acid bacteria are crucial for fermentation and food preservation.

Purpose of the Study:

• To investigate the role of onggi's porosity in lactic acid bacteria fermentation.
• To quantify the effect of onggi's gas permeability on carbon dioxide levels during fermentation.
• To develop a mathematical model explaining the fermentation process in onggi.

Main Methods:

• Fermentation of salted napa cabbage in both onggi and hermetic glassware.
• Measurement of carbon dioxide concentration over time as a fermentation indicator.
• Development and application of a mathematical model incorporating onggi's gas permeability.

Main Results:

• The mathematical model accurately described carbon dioxide generation rates in onggi.
• Onggi's porous walls facilitate carbon dioxide release, maintaining optimal conditions for lactic acid bacteria.
• The onggi's structure acts as a natural barrier against external contaminants, enhancing microbial safety.

Conclusions:

• The porosity of onggi plays a key role in regulating the internal environment for beneficial lactic acid bacteria.
• Onggi's unique properties provide a safe and efficient method for food fermentation and preservation.
• This study highlights the scientific basis of traditional Korean fermentation and suggests potential for energy-efficient food technology.