Phenolic contents, antioxidant and α-glucosidase inhibition properties of Nepalese strain buckwheat vegetables

Abstract

The sprouts, microgreens and leafy greens of common and tartary buckwheat of Nepalese strain were compared for the phenolic contents and biological activity. The tartary buckwheat samples expressed higher total phenolic and flavonoid contents compared to the common buckwheat. The sprouts had the highest total phenolic contents (9333.48 ± 150.23 and 6976.21 ± 213.65 mgGAE/100g dw in tartary and common buckwheat, respectively) whereas, the highest total flavonoid content was present in the leafy greens (7635.39 ± 141.40 and 4414.61 ± 70.85 mgRE/100g dw in tartary and common buckwheat respectively). The high performance liquid chromatography (HPLC) results revealed that the tartary buckwheat vegetables had higher rutin, (3800.28 ± 434.41 mg/100g in leafy greens), quercetin (159.75 ± 9.04 mg/100g in sprouts) and chlorogenic acid (293.47 ± 65.06 mg/100g in microgreens) contents than those of common buckwheat. However, other phenolics like vitexin, isovitexin, orientin and isoorientin contents were more abundant in common buckwheat. In biochemical assay, all three types of vegetable of common and tartary buckwheat showed higher antioxidant and α-glucosidase inhibition effect in dose dependent manner. Based on these results, it can be conformed that all the vegetables (microgreens, sprouts and leafy greens) of both varieties of buckwheat of Nepalese strains can be regarded as a potent sour ce of functional food.

Key words: Antioxidant, α-glucosidase, buckwheat vegetables, Nepalese strain buckwheat, phenolics.