Comparison of extraction methods on anthocyanin pigment attributes from mangosteen (Garcinia mangostana L.) fruit rind as potential food colourant

Abstract

The mangosteen fruit is mostly consumed for its pulp, and the rind, which accounts for more than 60 % of the total fruit weight, is discarded making it poor economic worth. The dark purple rind of mangosteen fruit is a rich source of anthocyanin pigment that can be used for food application if extracted using eco-friendly solvents. The aim of the study was to come up with an efficient, cheap and environmentally friendly method of anthocyanin pigment extraction from mangosteen fruit rind. Acidified solvent has shown to have higher recovery percentage of the pigment concentrate having higher TMAC (17,652.54 mg/L), colour density (1596.30 AU), polymeric colour (997.80 AU). Significantly highest recovery percentage (55.03), antioxidant activity measured by DPPH (2.29 l/ml), FRAP (2.83 l/ml), and ABTS (2.02 l/ml), total phenolics (32.25 mgGAE/100 g), total flavonoid content (40.02 mgQE/100 g), as well as the instrumental colour values indicating bright reddish-purple, were observed in microwave assisted extraction method with acidified solvent. By LC-MS/MS analysis, it was also evident that the rind contains a number of beneficial and health-promoting compounds, such as anthocyanins, xanthones, phenolics, flavonoids, coumarins, phoroglucinol derivatives, lignans, retinoids.