Effects of Roasting Condition on the Quality Characteristics and Oxidative Stabilities of Rice Germ

볶음 조건이 쌀눈의 품질 특성 및 산화안정성에 미치는 영향

  • Ko, Soon-Nam (Department of Food and Nutrition, College of Health Sciences, Korea University) ;
  • Kim, Chul-Jin (Korea Food Research Institute) ;
  • Kim, In-Hwan (Department of Food and Nutrition, College of Health Sciences, Korea University)
  • 고순남 (고려대학교 병설 보건대학 식품영양과) ;
  • 김철진 (한국식품개발연구원) ;
  • 김인환 (고려대학교 병설 보건대학 식품영양과)
  • Published : 2003.06.01

Abstract

In order to compare quality characteristics and oxidative stabilities of rice germs prepared under different roasting conditions, sensory evaluation, color value, tocols (tocopherol+tocotrienol) contents, and peroxide value were investigated. Optimum roasting temperatures for the best acceptability were 20, 10, and 6 min at 170, 180 and 190, respectively. Hunter color a values of rice germ increased as roasting temperature and time increased, whereas L value decreased. Peroxide values of unroasted, and roasted rice germs at $170^{\circ}C$ for 20 min, $180^{\circ}C$ for 10 min, and $190^{\circ}C$ for 6 min were 2.0, and 145.6, 169.5, and 182.9 meq/kg, respectively, after 9 days storage at $60^{\circ}C$. Four tocopherol and three tocotrienol isomers were identified, whereas no ${\beta}$-tocotrienol was detected. The major tocopherol and tocotrienol isomers in rice germ were ${\alpha}$-tocopherol and ${\alpha}$-tocotrienol, respectively. ${\alpha}$-Tocopherol content in roasted rice germ decreased significantly during storage, whereas those of ${\beta}$- and ${\gamma}$-tocopherols slowly decreased. ${\delta}$-Tocopherol had the highest stability among tocopherol isomers in roasted rice germ. Similar trends were observed in tocotrienol isomers.

Keywords

hunter color;peroxide value;rice germ;roasting condition;sensory evaluation;tocopherol;tocotrienol

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