Antioxidant Activities and Quality Characteristics of Germinated Rough Rice Tea according to Roasting Temperature, Time and Leaching Condition

볶음 조건 및 침출 조건에 따른 발아 벼차의 항산화 활성 및 품질 특성

  • Lee, Sang-Hoon (Department of Food Science and Technology, Chungbuk National University) ;
  • Lee, Youn-Ri (Department of Food Science and Technology, Chungbuk National University) ;
  • Hwang, In-Guk (Department of Food Science and Technology, Chungbuk National University) ;
  • Woo, Koan-Sik (Division of Functional Cereal Crop, National Institute of Crop Science, RDA) ;
  • Kim, Kyoung-Ho (Division of Winter Cereal & Forage Crop, National Institute of Crop Science, RDA) ;
  • Kim, Kee-Jong (Division of Winter Cereal & Forage Crop, National Institute of Crop Science, RDA) ;
  • Jeong, Heon-Sang (Department of Food Science and Technology, Chungbuk National University)
  • 이상훈 (충북대학교 식품공학과) ;
  • 이연리 (충북대학교 식품공학과) ;
  • 황인국 (충북대학교 식품공학과) ;
  • 우관식 (국립식량과학원 기능성작물부) ;
  • 김경호 (국립식량과학원 벼맥류부) ;
  • 김기종 (국립식량과학원 벼맥류부) ;
  • 정헌상 (충북대학교 식품공학과)
  • Published : 2009.08.31

Abstract

To verify the possibility of manufacturing a germinated rough rice tea, germinated rough rice was roasted at 200, 220, and $250^{\circ}C$ for 10, 20, and 30 min. The treated rice powder was then put into tea bags and leached for 1, 3, and 5 min, after which their antioxidant, physicochemical, and sensory characteristics were compared. The total polyphenol content and 2,2'-Azino-bis-(3-ethyl benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of the germinated rough rice tea increased as the roasting temperature increased as well as in response to increased roasting and leaching times. Furthermore, the greater the roasting temperature, roasting time, and leaching time, the greater the increase in total soluble solid contents. Moreover, the turbidity and browning index of the germinated rice tea rose as the roasting temperature, roasting time, and leaching time increased. Additionally, the pH tended to decrease as the roasting temperature, roasting time, and leaching time increased. Evaluation of the sensory characteristics of the germinated rice tea revealed that the formation of a Maillard reaction product in the course of heating the rice added a unique flavor, which led to increase preference for the color, flavor, and taste, and therefore, the overall preference.

발아 벼차의 이용 가능성을 검토하기 위해서 발아 벼를 볶음 온도, 볶음 시간, 침출 시간에 따른 항산화 활성, 이화학적 특성, 관능적 특성을 비교하였다. 발아 벼차의 항산화 활성으로 총 폴리페놀 함량과 총 항산화력을 측정하였으며, 각각 0.31-1.32 mg/g과 7.06-39.40 mg AA eq/100 g 범위로 나타나 볶음 온도가 높아지고 볶음 시간 및 침출 시간이 증가함에 따라 항산화 활성이 증가하는 경향을 나타내었다. 발아 벼차의 이화학적 특성으로는 볶음 온도, 볶음 시간, 침출시간을 달리하여 가용성 고형분 함량, 탁도, pH 및 갈변도를 측정하였다. 볶음 온도, 볶음 시간, 침출 시간이 증가할수록 가용성 고형분 함량이 현저히 증가하여 $250^{\circ}C$에서 30분간 볶음 처리 후 5분 침출시는 2.62%로 $200^{\circ}C$에서 30분간 볶음 처리 후 5분 침출한 경우의 0.62%보다 높았다. 발아벼차의 탁도는 볶음 온도가 높고 볶음 시간 및 침출 시간이 길수록 증가하였으며, 색도에서는 차이를 보이지 않았다. 발아벼차의 pH를 측정한 결과 볶음 온도, 볶음 시간, 침출 시간에 따라 큰 차이를 보이지는 않았지만 볶음 온도가 높고 볶음 시간 및 침출 시간이 길수록 pH는 감소하는 경향을 나타내었으며, 발아벼차의 갈변도는 볶음 온도가 높고 볶음 시간 및 침출 시간이 길수록 증가하는 경향을 나타내었다. 발아 벼차의 관능적 특성으로는 색, 향, 맛 및 전반적 기호도를 평가하였으며, 곡류의 볶음 처리에 따른 가열 과정에 의해 생성되는 갈색화 반응 생성물은 식품에 독특한 향미를 부여하여 향과 맛에 대한 기호도가 증가하였으며, 종합적 기호도 또한 높은 평가를 받았다.

Keywords

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