Determination of coenzyme Q10, coenzyme Q9, and melatonin contents in virgin argan oils: comparison with other edible vegetable oils

Abstract

Virgin argan oil possesses high antioxidant capacity (AC), which may be partially explained by its high content in antioxidant molecules such as polyphenols and tocopherols. However, the content in other antioxidant molecules, for example, coenzyme Q10 (CoQ10), coenzyme Q9 (CoQ9), and melatonin (Mel), which have been identified in other edible vegetable oils, have not been evaluated in virgin argan oil. Consequently, it was decided to evaluate the contents of CoQ10, CoQ9, and Mel in virgin argan oils and compare the results to those obtained in extra virgin olive oils and some varieties of seed oils. By the use of sensitive HPLC-EC/F methods, the results showed that virgin argan oil is a rich source of CoQ10 and Mel, but no CoQ9 was detected. Extra virgin olive oil showed higher levels of CoQ10 and lower levels of Mel than virgin argan oil. Between the seed oil samples, only virgin soybean oil showed higher CoQ10 and Mel levels than virgin argan oil. The results may be relevant for the contribution of CoQ10 and Mel to the biological activities of virgin argan oil.