배추김치의 식품학적 품질에 대한 굴 패각 분말의 영향

Abstract

Kimchi is one of the famous Korean traditional fermented foods. Kimchi has been mainly prepared with salted Chinese cabbage blended with various spices including red pepper, garlic, green onion, ginger and other minor ingredients. In addition, it has been known that lactic acid bacterial fermentation is associated with the ripping and food qualities of Kimchi. Thus, over-production of lactic acid by lactic acid bacteria results in the acidification of Kimchi that means deterioration. Therefore, many studies have been performed to extend the shelf-life of Kimchi by retarding or regulating lactic acid bacterial fermentation using non-thermal methods such as radiation, natural antimicrobial substances and pH adjuster. However, there are no commercially available non-thermal methods to make better quality of Kimchi except low temperature control. The object of this study was to investigate the effects of oyster shell powder (OSP) addition on extending self-life and enhancing food qualities of Chinese cabbage Kimchi (CCK) as non-thermal agent. In this study, it has been monitored on the changes of microbial levels, pH, acidity and sensory evaluation during the fermentation of Chinese cabbage Kimchi treated with various contents of OSP (OSP; 0%, 0.1%, 0.3%, 0.5% and 1%). Microbial assay showed the efficacy of OSP addition in CCK on inhibiting the growth of viable cells, total coliforms and lactic acid bacteria. Among of them, the addition of OSP exhibited the strongest growth inhibitory activity against lactic acid bacteria over the fermentation periods. After 18 day fermentation, the lactic acid bacterial counts in CCK treated with OSP (0.3%, 0.5% and 1%) were to be at least 1 log CFU/g lower than those of control CCK. In addition, the levels of pH and acidity in CCK treated with OSP were lower than those of control CCK over the fermentation periods. In CCK treated with 1% OSP, the acidity was not determined until 9 days of fermentation. In aspects of sensory evaluations on the effect of OSP to CCK, the crispness evaluation of CCK with 0.3% OSP showed higher score than control CCK after 21 day of fermentation. Also, overall evaluation of CCK with 0.3% OSP was higher than that of control CCK after 24 day of fermentation. Considering above results, it was concluded that OSP, especially 0.3% OSP treatment, will be useful to enhance food qualities and extend self-life of CCK while minimizing detrimental effects on the sensory characteristics. Furthermore, the results obtained in this study will contribute to develop an effective non-thermal method for enhancing food quality and extending self-life of other fermented food or non-sterilized foodstuffs as like Kimchi.