Characterization of polyphenols, phytosterols and tocopherols from longan (Dimocarpus longan Lour.) seed and mango (Mangifera indica L.) kernel

Abstract

The objectives of the present study were to determine the total antioxidant capacity and phenolic content of longan seeds and mango kernels, and further identify and characterize their polyphenols, phytosterols and tocopherols profiles, as well as cyanogenic compounds. The total antioxidant capacity was determined spectrophotometrically by the use of ABTS cation radical scavenging and ferric-reducing antioxidant power assays; whereas Folin - Ciocalteu reagent assay was employed to measure the total phenolic content. Polyphenols were separated on a Sephadex LH-20 chromatography column and further identified by LC/MS. Phytosterols were characterized and quantified by GC/MS after acid hydrolysis and saponification. Tocopherols were identified and quantified by HPLC with fluorescence detection after saponification. Dipstick assay was employed to determine the presence of cyanogenic glycosides. With regards to the promising results obtained, longan seeds and mango kernels could be used as potential sources of biopreservatives or functional food ingredients.