Difference in the contents of benzo(a)pyrene, sesamol and sesamolin, and volatile profiles in sesame oils

Abstract

The objective of present study was to investigate difference in the contents of benzo(a)pyrene (BaP), sesamol and sesamolin, and volatile profiles in sesame oils according to (1) different cultivated areas of sesame seeds [Ethiopia, India, China, Korea (Sinan, Muan, Yecheon, Uiseong)] and (2) the addition of adsorbents in sesame oil. Natural antioxidants were analyzed using a high performance liquid chromatograph-diode array detector, and BaP were detected using a high performance liquid chromatograph-fluorescence detector, whereas volatiles were analyzed using a gas chromatograph-mass spectrometer combined by solid phase micro-extraction. According to different cultivated areas of sesame seeds, there was difference in contents of natural antioxidants between samples. The contents of sesamol were lower in Korean sesame oils than those in Ethiopian, Indian, and Chinese sesame oils, whereas sesamolin contents were higher in sesame oils derived from Korea than those in sesame oils from other countries. Also, there was difference in the contents of BaP in sesame oils obtained from difference origins. Sesame oil samples made of seeds harvested from different countries were clearly separated on the basis of their volatile profiles. Pyrroles and sulfur-containing compounds, such as 1-ethyl-1H-pyrrole, 2-ethyl-4-methyl-1H-pyrrole, 2,4-dimethyl thiazole, 5-ethyl-4-methylthiazole, were mainly responsible for the discrimination of sesame oil samples. In the case of the addition of adsorbents to reduce BaP in sesame oil, the addition of D12 and D40 to sesame oil led to reduction in BaP of 32% and 46%, respectively. However, the content of BaP was only slightly decreased by the addition of celite, with no significant difference. After adding celite, D12, and D20, the contents of sesamol decreased by 12.52%, 7.71%, and 19.28%, respectively, compare to control sample, whereas those of sesamolin was reduced by 5.05%, 4.38%, and 5.08%, respectively. Although the contents of pyrazines, furan derivatives, and thiazoles, which are major volatiles in sesame oils, exhibited a decreasing tendency upon the addition of adsorbents, there were no significant differences compare to control.;본 연구에서는 (1) 참깨의 재배지역 (에티오피아, 인도, 중국, 신안, 무안, 예천, 의성) 및 (2) 흡착제 (규조토, 12-20 mesh size 활성탄, 20-40 mesh size 활성탄) 첨가에 따른 참기름 내 천연 항산화제 (sesamol and sesamolin) 및 벤조피렌 함량, 참기름의 휘발성 향기성분의 차이를 비교 분석하였다. 천연 항산화제 성분은 액체크로마토그래피-다이오드 어레이 검출기를 이용하여 비교하였고, 벤조피렌은 액체크로마토그래피-형광검출기를 이용하였으며, 향기성분은 고체미세추출법으로 추출 후 가스크로마토그래피-질량 분석기를 이용하여 분석하였다. 참깨의 재배지역에 따라 천연 항산화제 함량은 차이를 보였는데 국내산 참깨로 제조한 참기름에서는 sesamolin의 함량이 비교적 높게 나타났고, 수입산 참깨로 제조한 참기름에서는 sesamol의 함량이 높게 나타났다. 또한 벤조피렌 함량도 참깨의 재배 지역별로 차이를 보였다. 천연 항산화제 함량과 벤조피렌 함량과의 상관관계는 발견하지 못하였다. 1-ethyl-1H-pyrrole, 2-ethyl-4-methyl-1H-pyrrole, 2,4-dimethyl thiazole, 5-ethyl-4-methylthiazole 등의 휘발성 성분이 참깨의 재배지역별 참기름을 구분하는데 기여하는 주요 성분들로 동정되었다. 참기름 내 벤조피렌 저감화를 위해 흡착제를 첨가하는 경우, 12-20 mesh size 활성탄, 20-40 mesh size 활성탄 처리 시 참기름 내 벤조피렌 함량이 각각 32%와 46% 감소하였으나, 규조토 첨가 시에는 벤조피렌 감소효과가 거의 나타나지 않았다. 천연 항산화제 함량의 경우 규조토, 12-20 mesh size 활성탄, 20-40 mesh size 활성탄 첨가 시 sesamol 함량은 12.52%, 7.71%, 19.28% 정도 감소하였고, sesamolin의 함량은 5.05%, 4.38%, 5.08% 감소하였다. 참기름의 주요 휘발성 향기성분인 pyrazines, furan derivatives, thiazoles 은 흡착제 첨가에 따라 감소하는 경향을 보였지만 유의적인 차이는 없었다.