Extraction of phenolic compounds from cashew nut shell waste by microwave assisted method and appraisal of certain properties of shell extract

Abstract

This work aimed to optimize the process of microwave assisted extraction (MAE) of phenolic compounds from cashew nut shell (CNS) wastes using water and ethanol. In this study, the effect of extractants (ethanol/water) ratio, temperature, extraction time and its effects on the process of extraction and properties of CNS extract (refractive index, viscosity, specific gravity, pH, and color) obtained were studied. The extract was examined to detect the total or integrated polyphenolic compounds by the Folin-Ciocalteu (FC) method using visible scanning spectrophotometer. Also identified an accurate microwave energy (AME) for extraction that conclude microwave assisted extraction process consumed shorter process time when compared to conventional method. The desired results of MAE process obtained at 98 °C with a solvent/plant ratio of 20/1. From the results, the optimum MAE conditions to extract polyphenolic compounds from CNS wastes were determined (98 °C, 40 min, 50% ethanol & 50% water (48 ml)).These conditions given a TPC value of 19.94 mg GAE g−1dw and TPC value of 321.82 mg GAE L−1.This findings can also be tested with other plant based sources for extracting poly phenolic compounds with water.