Abstract
This study was carried out to investigate potential use of Scutellaria bicalensis Georgi (SBG) as an ingredient for extending the shelf life of tofu. The spore of Bacillus sp. KN-4 was isolated from commercial tofu and inoculated to soybean milk to prepare artificially contaminated tofu. The contaminated tofu was stored in the presence of 0.05 and 1% of SBG extract at $25^{\circ}C$ for 72 hrs. The pH changes of contaminated tofu with SBG extract was slower than those of control during storage. The degree of pH change decreased as the concentration of SBG extract was increased from 0.05% to 0.1%. The change of titratable acidity of the tofu showed the same tendency as pH change during storage. Total cell number of the SBG extract added tofu was lower about $1{\sim}2$ log cycle (0.05% SBG extract) or $2{\sim}3$ log cycle (0.1% SBG extract) than that of control after storage for 12 hrs at $25^{\circ}C$. The color changes of the tofu did not show any difference with and without SBG during storage at $25^{\circ}C$. The strength and hardness of the tofu was improved by the addition of SBG extract. Especially, the strength and hardness of tofu in the Presence of 0.1% SBG extract did not change during storage time. The sensory Qualify of SBG extract added tofu was better than control in texture, but not in taste and color. The overall acceptability of the SBG extract added tofu was similar to control.
항균활성, 항산화성 등 다양한 생리활성이 있는 황금 에탄올 추출물의 두부 저장성 증진 효과를 검토하기 위하여 황금에탄올 추출물을 0.05%, 0.1%를 첨가하고, Bacillus sp. KN-4포자를 접종한 두부를 $25^{\circ}C$에서 저장하면서 품질변화를 측정한 결과, 총균수가 $10^7 CFU/mL$에 도달하는 시간이 대조구는 24시간, 황금 에탄을 추출물 0.05% 첨가구는 36시간, 0.1% 첨가구는 48시간이 소요되었다. pH와 산도는 12시간까지는 큰 차이를 보이지 않았으나, 저장 24시간 이후의 대조구에서는 pH가 급격하게 감소되었고, 산도는 증가하였다. Strength, hardness는 저장초기 대조구보다 황금 에탄올 추출물 첨가구가 높게 나타났으며, 대조구는 저장 초기부터, 0.05% 첨가구는 24시간부터 다소 낮아지는 경향을 나타내었으나, 0.1% 첨가구는 저장기간 중 뚜렷한 변화가 관찰되지 않았다. 관능적인 평가는 대조구에 비해 조직감은 첨가구가, 맛은 대조구가 높았으며, 그 외 색상, 풍미 등에서는 첨가구와 대조구간의 유의적인 차이를 나타내지 않았다.
