Extraction of polyphenols from cashew nutshell.

Abstract

Cashew nut shell liquid (CNSL) was extracted from cashew nut shell by indirect leaching process using soxhlet extraction equipment. Normal hexane (n-hexane) was used as solvent. The operating conditions for the extraction were 680C and 1 atmosphere in every 100g of cashew nut shell used for the extraction, 35gCNSL was obtained. The CNSL was further separated into cardol, cardanol and anacardic acid (polyphenol) using an amine extractant (alanine) with the aid of shake-out separation equipment. Subsequently, the polyphenol was further separated into dihydric phenols (resorcinol) and monohydric phenol (phenol). The physical separation of the CNSL showed that it consisted of about 10% cardol (dicarboxy- pentadica-dienylbenzene), 50% cardanol and 30% anacardic acid (carbopenta-dica dienylphenol) (with the remainder being made up of other substances) whose boiling points and specific gravities were 900C and 0.9g/m3 1750C and 1.1g/m3 and 1790C and 1.2g/m3.