Estimation of pressure and volume changes for packages of kimchi, a Korean fermented vegetable

✍ Scribed by Dong Sun Lee; Ho Ryoung Kwon; Jung Uk. Ha

• Book ID: 101288500
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 205 KB
• Volume: 10
• Category: Article
• ISSN: 0894-3214
• DOI: 10.1002/(sici)1099-1522(199701/02)10:1<15::aid-pts378>3.0.co;2-a

✦ Synopsis

Kimchi, a vegetable containing lactic acid bacteria, produces CO 2 gas because of its continued fermentation during storage, resulting in a pressure build-up and extensive expansion of its containers. This pressure build-up and volume expansion occurring in packaged kimchi constitute a serious problem, since it makes the product unattractive and difficult to market. As an attempt to solve this problem, a kinetic model for CO 2 production in kimchi during storage was established as a function of salt content and temperature to monitor the pressure and volume variations of the packages. The concentrations of CO 2 in headspace and CO 2 dissolved in brine were related by Henry's law, which allowed easy determination of CO 2 production from fermentation and offered a useful estimate of the CO 2 partial pressure in the packages. The CO 2 production in kimchi consisted of two stages of constant rate and could be described for both stages as R CO 2 , i =K i exp ( Ϫ E ai /RT), where K i is a function of salt content. In the model, the pressure and volume of the packages were presumed to be the sum of contributions of the CO 2 produced during the fermentation as well as O 2 and N 2 from entrapped air. Variations of pressure and volume due to temperature change were assumed to be governed by the ideal gas law. Measurements of pressure and volume for te kimchi packages stored both at constant and changing temperatures were in good agreement with the predicted values, thus confirming the validity of the proposed model.