Melatonin‐rich, erucic acid‐lean nutraceutical supplements by microwave‐assisted solvent extraction of brown and yellow mustard seeds

Abstract

The microwave-assisted solvent extraction (MASE) parameters optimized by Taguchi L9 (34) orthogonal array design to obtain extracts with a favorable combination of high melatonin-cum-low erucic acid content from Brassica juncea (BJ) and Brassica campestris (BC) seeds were: seed particle diameter of 500 μm for BJ and 420 μm for BC seeds, 1:10 sample to solvent (50% ethanolic water) ratio, 180 W microwave power, and 10 min extraction time. The yield of melatonin from BC was relatively higher owing to its greater protein and/or moisture content(s). Biochemical characterization confirmed a synergistic consortium of antioxidants in the extracts, viz. melatonin along with co-extracted ascorbic acid, limonene, and linalool. At the optimized condition, the actual power absorbed by the seed-solvent matrices (21.5 W in BJ-, 24.6 W in BC-MASE extracts) was lower compared to the microwave power applied (180 W) during MASE. Our studies affirm safe consumption of the extracts as melatonin-rich nutraceutical supplements. Novelty impact statement This work is of significance since melatonin which is commercially used as a drug has been extracted from an unconventional source, that is, from an oilseed crop for use as a food antioxidant. MASE has been conducted for the first time with green solvents for obtaining “melatonin rich-cum-erucic acid-lean” extracts of brown and yellow mustard seeds embracing natural “antioxidant synergy” within. The procedure established in this work could be easily scaled up to commercial level extraction of “a synergistic consortium of antioxidants” from other oilseeds (or allied food matrices).