The Content and Composition of Total, Free, and Esterified Sterols of Lotus Plumule Oil by GC-MS/FID

This study investigated the content and composition of total, free, and esterified sterols of three varieties of lotus plumule oil (Hunan lotus, Jiangxi lotus, and Fujian lotus) using GC-MS/FID. The fatty acid composition of sterol fatty acid esters (SFAE) was also analyzed and compared with that of triglycerides. Results showed that total sterol of lotus plumule oil (12.10-14.21 g/100 g) was higher than that of other plant oils (corn germ oil, 1.11 g/100 g; rapeseed oil, 0.78 g/100 g). No significant difference was found among the total sterol contents of the three types of lotus plumule oils (p > 0.05). Most sterol existed in ester forms (81.8-89.1%) rather than in free forms (8.4-10.1%). beta-Sitosterol (71.4-73.4%), and campesterol (6.2-7.5%) were the predominant fractions of free sterols. beta-Sitosterol (41.3-53.7%) and a dagger 5-avenasterol (27.1-31.1%) were the predominant fractions of esterified sterols, followed by campesterol (12.1-13.0%) and a dagger 7-avenasterol (3.4-3.7%). Linoleic acid (63.6-65.8%), oleic acid (8.3-10.4%), and behenic acid (9.0-9.9%) were the main fatty acids of SFAE, which were different from those of triglycerides. The results from this study suggest that lotus plumule oil may be a good resource of SFAE and can be used as a supplemental ingredient in functional foods.