Changes in Enzymatic Activities during Eoyukjang Fermentation

Eoyukjang is a traditional sauce-type of Korean food that is similar to a soybean sauce made from fermented soybeans, and it is produced from a fermented mixture of sea foods, meats, and meju (soybean paste). This study examined periodical changes in the enzymatic activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, protease, lipase, and lipoxygenase within the culture broth and solids of eoyukjang during 1 year of fermentation. The eoyukjang solids had 234-532% higher protein content than the culture broth. The specific activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease increased in both the culture broth and solids. Particularly, in the culture broth, ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease activities rapidly increased (3- to 8-fold) until 10 months of fermentation, and then drastically decreased. However, the activities of lipase and lipoxygenase in both the culture broth and solids were less than 0.05 unit/mg of protein, respectively, throughout fermentation; thus, their activity levels were low and changed little over the 12 months. Overall, while the solids had higher protein content than the culture broth, the broth had greater enzyme activity levels during eoyukjang preparation.

어육장 발효 시 생성되는 효소의 활성 변화

한국의 전통 한국의 전통적인 식품 중, 대표적인 장류로서 반가 식품에 해당하는 수조육류와 어패류를 첨가하여 제조한 어육장(규합총서의 방법)을 발효시키되, 2달 간격으로 발효기간에 따라 ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, lipase, lipoxygenase 및 protease의 활성을 각각 측정하여 경시적 변화를 관찰하였다. 어육장을 액체와 고체시료로 나누어 이상에서 열거한 효소들의 활성을 측정한 결과, lipase 및 lipoxygenase의 비활성도는 모두 0.05unit/mg protein 이하로서 효소 활성도가 낮은 수준이었으며, 1년동안의 발효·숙성기간 중 비활성 증감변화도 미미하였다. 반면,${\alpha}$-amylase, esterase, ${\beta}$-glucosidase 및 protease는 숙성기간에 따라 효소의 활성이 증가하는 것을 확인할 수 있었고, 특히 10개월째에는 액체시료의 경우 4종류 효소의 비활성이 급격히 증가하였다가 감소하는 것을 확인할 수 있었다. 전반적으로 고체시료의 단백질 함량은 액체시료보다 높았지만, 액체시료의 비활성이 고체시료보다 2-5배 이상 높은 결과를 확인하였다.