Oxidative Stability of Sesame Oil Prepared from Black Sesame Flour

Oxidative stabilities of sesame oil prepared from black sesame flour and white sesame flour, and commercial sesame oil prepared from whole white sesame were compared by measuring oxidation induction periods, peroxide values and electron donating abilities of each oil. Oxidation induction period (12.25 hr) of sesame oil prepared from black sesame flour was longer than those (4.37 and 9.1 hr, respectively) of sesame oil from white sesame flour and commercial sesame oil. Peroxide values of sesame oil prepared from black sesame flour, sesame oil prepared from white sesame flour and commercial sesame oil were 1.3, 18.2 and 1.7 meq/kg oil, respectively. We ascertained that the oxidative stability of sesame oil prepared from black sesame flour was superior than sesame oil from white sesame flour as well as ommercial sesame oil. This was based on the fact that electron donating ability of sesame oil prepared from black sesame flour was 9% higher than that of sesame oil prepared from white sesame flour at the same concentration. The superior oxidative stability of sesame oil prepared from black sesame flour was expected, not only because only it had lignans such as sesamol and sesamolin, but also because of its brownish coloring compounds such as tannin which were not contained in white sesame flour.

흑참깨분으로 착유한 참기름의 산화안정성

흑참깨분 참기름과 흰참깨분 참기름 및 흰통참깨로 제조한 상업용 참기름의 산화유도기간, 과산화물가, 전자공여능을 측정하여 각 참기름의 산화안전성을 비교하였다. 흑참깨분 참기름의 산화 유도기간은 평균 12.25시간으로 흰참깨분 참기름의 4.37시간에 비하여 2.8배 이상인 것으로 나타났으며, 상업용 참기름은 9.1시간이었다. 저장 12일 후 과산화물가를 비교해 보면 흑참깨분 참기름이 1.3 meq/kg oil, 흰참깨분 참기름이 18.2 meq/kg oil, 상업용 참기름이 1.7 meq/kg oil인 것으로 나타났다. 또한 전자공여능은 흑참깨분 참기름이 각 사용 농도 별로 흰참깨분 참기름에 비해 평균 9% 이상 높은 것으로 나타남에 따라, 동일한 조건에서 흑참깨분 참기름의 산화안전성이 흰참깨분 참기름이나 상업용 참기름에 비해서도 대등하거나 우수함을 알 수 있었다. 이는 흑참깨분 참기름에는 기존의 참기름에 함유된 sesamol 및 sesamolin과 같은 리그난류 뿐 만 아니라 흰참깨분 참기름에는 들어 있지 않은 적갈색 탄닌계 색소 성분이 존재하기 때문인 것으로 예측되었다.