Portfolio of beetroot (Beta vulgaris L.) peel extracts concentrated by nanofiltration membrane

Abstract

Membrane process is an intelligent alternative way of concentration, preferably for organic juices rich in thermolabile natural components. The expectation is to scale up the extraction of desired compounds from agro-industrial wastes through modernized concentration method. Recovery of betalains, phenolic, and antioxidant from beetroot peel extracts was accomplished by nanofiltration membrane (NF 200) at a recirculation flow rate (400 L h^-1) and feed temperature (30 ºC) under constant transmembrane pressure (40 bar). Characterization of betaxanthin, betacyanin, phenolic, and antioxidant activity by spectrophotometric analysis revealed that the final samples contain these compounds respectively: 202.25±3.26 mg.L^-1, 360.07±8.43 mg.L^-1, 987.79±19.18 mg.L^-1, 642.06±14.78 mg.L^-1 (pure water); 206.62±1.37 mg.L^-1, 339.72±2.89 mg.L^-1, 972.72±47.49 mg.L^-1, 745.97±25.45 mg.L^-1 (ethanol-water). Final samples exhibit vivid colour and a considerably large amount of desired compounds compared to crude extracts and could have industrial applications.