The unique compositions of steryl ferulates in foxtail millet, barnyard millet and naked barley

Although oryzanol in rice bran is one of the most utilised steryl ferulates (SFs, ferulic acid/coumaric acid esters of phytosterol/triterpene alcohol), SFs are also present in other cereals. Thus, we herein report the SF profiles present in various cereals, pseudo-cereals and millets using a high performance liquid chromatography (HPLC) method. The SF contents of whole foxtail millet, whole proso millet, and whole barnyard millet were 28.9, 0.2, and 4.8 mg-oryzanol equivalent/100 g, respectively, indicating that the SF content in whole foxtail millet was about 80% of oryzanol in brown rice. Using an atmospheric pressure chemical ionisation method combined with mass spectrometry (APCI-MS), the SF components from several millets and cereals were identified. It revealed that SFs of whole foxtail millet was composed of stigmastanyl ferulate (73%), stigmastanyl coumarate (10%), and others (17%). Furthermore, SF compositions of whole barnyard millet and naked barley were firstly determined and they were considerably different from those of other cereals.