Development and application of a novel analytical method for the determination of 8 plant sterols/stanols in 22 legumes samples

Phytosterols (PS) are a group of chemical compounds of plant origin, able to reduce blood levels of bad cholesterol and the consequent risk of atherosclerosis. In this study, an HPLC-DAD method was developed for the determination of cholesterol and 7 main PSs (β-sitosterol, campestanol, campesterol, fucosterol, sitostanol, stigmasterol, and stigmastanol) in legumes samples. The method was validated, and satisfactory results were obtained in terms of linearity (0.995 – 0.999), repeatability, LOD, and LOQ. Moreover, compared to standard extraction methods, an innovative extraction process of PS was developed through ultrasound-assisted extraction (UAE) allowing a reduction of extraction time by half while maintaining a high extraction efficiency. The developed PS extraction and analytical methods were applied for the first time to 22 types of legumes (beans, lentils, chickpeas, whole, or dehulled). 6 PS were observed in legumes with levels ranging from 86.4 mg kg−1 (roveja) to 699.9 mg kg−1 (black chickpeas). These results confirm that legumes should be included in the diet as great sources of cholesterol-lowering agents.