Effect of refining on the lignan content and oxidative stability of oil pressed from roasted sesame seed

Authors

  • Shimin Wu,

    Corresponding author
    1. Bor S. Luh Food Safety Research Center, Shanghai Jiao Tong University, Shanghai, China
    • Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
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    • Joint first authors, who contributed equally to this work.
  • Lin Wang,

    1. Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
    2. Bor S. Luh Food Safety Research Center, Shanghai Jiao Tong University, Shanghai, China
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    • Joint first authors, who contributed equally to this work.
  • Feiya Shu,

    1. Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
    2. Bor S. Luh Food Safety Research Center, Shanghai Jiao Tong University, Shanghai, China
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  • Wenming Cao,

    1. Shanghai Grain Science Research Institute, Shanghai, China
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  • Fengxiang Chen,

    1. Shanghai Grain Science Research Institute, Shanghai, China
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  • Xingguo Wang

    1. State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, China
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Correspondent: Fax: +86 21 34205717; e-mail: wushimin@sjtu.edu.cn

Summary

Oxidative stability of pressed and refined sesame oils during seven consecutive months of storage at room temperature was studied comparatively. Lignans, peroxide value (PV), p-anisidine value (AV) and total oxidation value (TOTOX) were determined as evaluation indices. PV, AV and TOTOX of sunflower, corn and peanut oils were simultaneously monitored to compare their oxidative storage stabilities with the sesame oils. The total amount of lignans in the pressed and refined sesame oils were 1103 and 790 mg per 100 g respectively. The contents of sesamin and sesemolin in the pressed sesame oil were 734 and 369 mg per 100 g respectively. Sesamin and sesamolin content were reduced by 256 and 159 mg per 100 g, respectively, after refining. Nearly 40% of the sesamin epimerised to asarinin after oil refining. The results indicate that sesame oils pressed from roasted seed have far superior storage stability to oxidation than the other vegetable oils. This difference may be due to much higher sesamin and sesamolin contents in the pressed sesame oils. The results suggest lignan compositions and levels could be used as key indicators for evaluating the oxidative storage stability of sesame oil products as well as to differentiate between pressed and refined sesame oils.

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