Increased qualities and health functional effects of ganjang fermented in onggi

Abstract

The quality and health functional effects of ganjang fermented in onggi and other ordinary containers were studied. The containers employed for ganjang fermentation included non-glazed onggi (onggi without glaze, OWOG), glazed onggi (onggi with glaze, OWG), ceramics (CRM), stainless steel containers (STL), and glass bottles (GLA). Grain-type meju with salt and water was fermented in each container at 37°C for 40 days. The pH decreased slowly and the acidity gradually increased, whereas the amino-type nitrogen content increased, although the ammonia-type nitrogen content was significantly decreased (p<0.05) for ganjang fermented in onggi. The abundance of yeasts, molds, and lactic acid bacteria was significantly increased whereas the total bacteria content decreased in OWOG and OWG during fermentation compared to that in the other types of containers. Ganjang fermented in onggi exhibited better antioxidant, antimutagenic, and anticancer effects than the samples fermented in other container types. Overall, the obtained results indicated that onggi, especially OWOG, was the best container for the fermentation of ganjang to ensure high food quality and health functions.