Simultaneous analysis of free phytosterols and phytosterol glycosides in rice bran by SPE/GC-MS

In this study, free phytosterols and phytosterol glycosides in rice bran were successfully separated and analyzed using solid-phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS). The results showed that free phytosterols in rice bran included ergosterol (129 +/- 8 mu g/g rice bran), campesterol (126 +/- 9 mu g/g rice bran), stigmasterol (106 +/- 9 mu g/g rice bran), 13-sitosterol (305 +/- 10 mu g/g rice bran), cycloartenol (80.5 +/- 3.9 mu g/g rice bran) and 24-methylenecycloartenol (87.1 +/- 2.2 mu g/g rice bran), while phytosterol glycosides included campesterol glucoside (16.0 +/- 1.3 mu g/g rice bran), stigmasterol glucoside (99.0 +/- 4.9 mu g/g rice bran) and 13-sitosterol glucoside (133 +/- 7 mu g/g rice bran). The methodological validation indicated that this method could accurately quantify free phytosterols and phytosterol glycosides in rice bran. This study provided a new direction to establish a rapid and simple method for the simultaneous determination of different forms of phytosterols in foods.