The effects of extraction methods on sesame oil stability

The oxidative stability of sesame oil, as measured by the Rancimat test, was shown to be dependent on extraction methods and seed pre-treatment. Oils extracted from whole seeds were more stable than those extracted from dehulled seeds by the same method. Extraction of the same seeds with polar solvents and effective seed crushing yielded more-stable oils (16.7-21.3 Rancimat hours) compared with extraction with nonpolar solvents and coarsely crushed or pressed seeds (4.5-6.4 Rancimat hours). Heptane-isopropanol (3:1, vol/vol) provided slightly more stable oils than n-hexane by the same method. Results are discussed in relation to some of the major anti- and prooxidants present in the oils.