두부는 식물성 단백질 자원의 식품으로 세계적으로 잘 알려져 있으며 우리나라의 전통식품이다. 최근 두부가 건강식품으로 인식되면서 품질 고급화를 위한 방안으로 화학 첨가물이 아닌 천연응고제로서 석류즙을 사용하여 두부를 제조하여 기계적 및 관능적 특성의 품질특성을 조사하고 저장성을 살펴보았다. 두부의 수율을 대조군이 485g/500ml이었으나 석류즙 첨가 두부군에서는 석류즙 3%(49.3g/500mL)가 가장 높고 석류즙 2%, 4% 순이었다. 두부여액의 탁도는 석류즙 첨가량이 많아질수록 높에 나타났으며 여액의 pH는 석류즙 첨가 두부가 대조군보다 낮게 나타났다. 두부의 색도에서 L(lightness)값은 대조군이 가장 높았으며 탁한 붉은 색의 석류즙 두부는 첨가량이 증가될수록 감소하였다. a(redness)값은 석류즙 첨가량이 증가될수록 커졌으며 b(yellowness)값은 대조군이 석류즙 첨가 두부군보다 높았다. 두부의 texture에서 경도(hardness)는 석류즙 첨가 두부가 더 단단하였고 응집성(cohesiveness)은 석류즙 4%, 5% 첨가군이 대조군보다 높고, 석류즙 1%, 2%, 3% 첨가군보다 낮았다. 탄력성(springness)은 P4〉P5〉P3〉P2〉P1순이며 검성은 석류즙 3%첨가군이 GDL두부와 유사한 특성을 보였으며(p〈.001), 부지짐성(brittleness)은 석류즙을 많이 첨가할수록 높아지는 경향이 있었다. 두부를 0℃에 저장하는 동안 pH는 대조군은 증가하며 석류즙 첨가 두부는 감소하는 경향을 보였으며 산도에서 대조군은 석류즙 첨가 두부와 같이 증가하였으며 두부의 저장성에서 대조군은 12일 지나면서 107 CFU/g을 넘어 부패가 진행되었으나 석류즙첨가 두부는 세균의 증식속도가 감소되어 전 기간동안 대조군에 비해 저장성 연장을 볼 수 있었다. 두부의 미세구조에서 석류즙 2%, 3% 첨가 두부가 대조군과 균일하게 구조를 나타냈으며 석류즙 첨가량이 증가할수록 입자가 크고 불규칙하며 거칠었다. 두부의 관능특성에서는 외관이 기호도는 대조군이 가장 높았으나 석류즙 첨가 두부군에서는 석류즙 2% 첨가 두부가 외관(appearance), 향미(flavor), 맛(taste), 질감(testure)에서 가장 높았다.

This study was investigated the utilization of pomegranate(P) as coagulants for 새려 manufacture, the quality characteristics and shelf-life on tofu made by P1(fruit juice of pomegranate 1%) and P2(fruit juice of pomegranate 2%) and P3(fruit juice of pomegranate 3%) and P4(fruit juice of pomegranate 4%) and P5(fruit juice of pomegranate 5%) were investigated and compared to G.D.L(C). And also, total microbe and tatal acid of the tofu were determined during storage at 0℃. The results are summarized as follow P3(493.3g/500ml) compared to C(485g/500ml) showed the highest yield. Turbidity of tofu was increased as the proportion of pomegranate was increased, while pH of tofu was increased as the proportion of pomegranate was decreased. L*** value of C tofu was highest, a*** value of tofu was increased as the proportion of pomegranate was increased and b*** value of C tofu was higher than those of other tofus. The hardness of tofu coagulated with pomegranate showed higher than that of coagulated G.D.L. The cohesiveness of P4, P5 showed higher than C tofu, but those of other tofus showed lower than C tofu. The springiness of tofu showed in the order of P4〉P5〉P3〉P2〉P1, gumminess of P5 tofu was highest. The Brittleness of tofu was increased as the proportion of pomegranate increased. The pH value of tofu coagulated with pomegranate increased during storage at 0℃. During the storage period of tofu, pH and total acid showed a maximum change in C tofu. Generally the total plate counts of bacteria of all tofu increased during storage at 0℃, and those of tofu with added pomegranate were shown to be lower than C tofu. The results of S.E.M(scanning electron microscopes), the lower hardness showed the more soft and the smaller particle, The particle of C tofu was small and uniformity but the size of P4, P5 tofu showed coarse. In the sensory evaluation of all tofu, sleekness, nutty, chewiness and smoothness, appearance and overall quality was the highest in C tofu. In the sensory evaluation of tofus coagulated with pomegranate. overall quality was the highest in P2.

• 김지영 | Kim, Ji-Young
• 박금순 | Park, Geum-Soon