Optimization of recovery of antioxidants from the coconut shell using Response Surface Methodology

Abstract

Coconut shell is an important byproduct of Cocos nucifera L. which is largely being wasted. The present study is focused on optimizing the extraction process of phenolic compounds and also to evaluate its physico-chemical and antioxidant properties. After studying the effect of different solvents and different extraction conditions, methanol was found to be the most effective solvent and extraction at 90^oC was suitable to give high phenolic yield (4045 mg GAE/100 g). For further precision of the ideal conditions, response surface methodology was carried out to optimize the solvent concentration, temperature and extraction time. The results revealed that methanol at 72%, extraction time 167 min and temperature 68^oC yielded maximal level of polyphenols from coconut shell. Both extraction temperature and solvent concentration were found to have significant effect on the phenolic yield. Suitable conditions could be applied to recover the antioxidant phenolic compounds from the coconut shell, an agricultural byproduct available at huge quantity in India. The physico-chemical and antioxidant properties of methanolic extract of coconut shell were noticed to be suitable for its application in food and pharmaceutical industries.