Simultaneous extraction of proteins and carbohydrates, including phenolics, antioxidants, and macamide B from Peruvian maca (Lepidium meyenii Walp.)

Abstract

Maca (Lepidium meyenii Walp.) has been used for nutritional and traditional purposes, owing to its chemical composition and the presence of bioactive compounds. This study aimed to develop and optimize a maceration-based method for the simultaneous extraction of total phenolic compounds (TPCs), total flavonoids (TFs), radical-scavenging activity (RSA), soluble proteins (SPs), total sugars (TSs), reducing sugars (RSs), and macamide B from maca using 95% ethanol and acidified ethanol. The effects of extraction parameters, including temperature, solvent-to-solid ratio, time, and acid concentration, on the extraction yield of TPCs, TFs, RSA, SPs, TSs, RSs, and macamide B were investigated. Optimal extraction was achieved at 40-60℃ for 5-7.5 h with the solvent-to-solid ratio of 100:10. The addition of hydrochloric acid (HCl) to ethanol significantly improved the extraction yield, and maximum extraction was achieved using 1 N HCl in ethanol. The RSA of the ethanolic extracts showed a significant linear correlation (p<0.001) with total extraction yield, TPCs, SPs, and TSs. These results imply that polyphenolic compounds, SPs/peptides, and polysaccharides are important determinants for the antioxidant function of maca. The optimized condition may be employed in nutraceutical industries to extract bioactive compounds from maca.