Determination of the contents of the main biochemical compounds of Adlay (Coxi lachrymal-jobi)

Adlay (Coxi lachrymal-jobi), an annual crop, has long been used in traditional Chinese medicine for its biological activity and as a nourishing food. Its phytochemical composition has been extensively studied; however, information on its policosanol (PC) and phytosterol content is scarce. The objective of this study was to examine and compare the PC, phytosterol and oleamide contents of different fractions of adlay collected from Laos, Thailand, Vietnam and Taiwan. Biochemical compositions of the samples were identified using a gas chromatograph coupled with a mass spectrometer (GC–MS). The adlay bran had higher contents of policosanols (246 mg/kg), phytosterols (4733 mg/kg) and oleamide (45.8 mg/kg) than had hulled and polished fractions. Although plant sterols reduce cholesterol absorption, policosanols may inhibit endogenous cholesterol synthesis. Although adlay contains beneficial phytochemicals that justify its use as a food ingredient or dietary supplement, research is still needed to confirm its traditional use in Asian medicine.