Extraction and Purification of Bioactive Phytosterols from Edible Seaweeds

Phytosterols are lipophilic steroid alcohols found in nature (almost all plant species and some seaweeds) that differ from cholesterol in the side chain bound in their C-17 position and degree of saturation of the ring structure. Besides existing in their free form, phytosterols also appear in conjugates, in which the 3β-OH group is esterified to a fatty acid or a hydroxycinnamic acid, or even glycosylated with a hexose (usually glucose) or a 6-fatty-acyl hexose. The saponification process is one of the most popular methods for phytosterol analysis and involves the hydrolysis of the conjugates into their free form. Here, we describe a method for extraction and purification of fatty acid-esterified phytosterols, based on alkaline saponification of the dry biomass.