Abstract
The effect of far-infrared (FIR) irradiation and heat treatment on the antioxidant activity of extracts from defatted soybean meal (DSM) was evaluated. DSM were placed in pyrex petri dishes (8.0 cm diameter) and irradiated at $150^{\circ}C$ for 5, 10, 15, 20, 40 or 60 min with a FIR heater or simple heater. After FIR irradiation or simple heat treatment at same conditions, methanol extracts of DSM were prepared and total phenol contents (TPC), radical scavenging activity (RSA) and reducing power of the extracts were determined. The antioxidant activities of the extracts increased as the time of heating or FIR-irradiation increased. When DSM were FIR-irradiated at $150^{\circ}C$ for 15 min, the values of TPC, RSA, and reducing power of the extracts increased from 31.62 mg/ml to 57.51 mg/ml, 11.6% to 53.1%, and 0.068 to 0.147, respectively, compared to the untreated controls. Simple heat treatment of DSM under the same conditions ($150^{\circ}C$ for 15 min) also increased the TPC, RSA, and reducing power of the extracts from to 58.04 mg/ml, 65.2% and 0.160, respectively. The results indicated that appropriate FIR-irradiation or heat treatment on DSM increased the antioxidant activities of methanolic extracts.
원적외선 조사 및 일반 열처리가 탈지대두박의 항산화능에 미치는 영향을 조사하기 위하여 $150^{\circ}C$에서 각각 5, 10, 15, 20, 40 그리고 60분간 처리한 후, 메탄올 추출물을 제조하여 총 페놀함량, DPPH 라디칼 소거능 그리고 환원력을 측정하였다. 이들 측정 결과, 무처리구 31.62 mg/ml, 11.6％, 0.068에 비해 원적외선을 $150^{\circ}C$에서 15분간 조사한 처리구는 각각 57.51 mg/ml, 53.1%, 0.147로 증가하였다. 한편, $150^{\circ}C$에서 15분간 일반 열처리한 시료의 경우는 각각 58.04 mg/ml, 65.2%, 0.160로 증가하였다. 그러나 원적외선 조사 및 일반 열처리를 20분간 이상하면 점차 감소하는 경향을 보였다. 이상의 결과는 적당한 조건에서의 원적외선과 열처리 조사가 탈지대두박에 존재하는 페놀 화합물의 추출을 촉진하며 항산화능을 향상시킴을 의미한다.
