Extraction of phenolic compounds from Temnocalyx obovatus

Abstract

Phenolic compounds yield in plant extracts depend on the method employed in the extraction process. In this study, we investigated systematically, a method of determination of extraction yield of antioxidant compounds from Temnocalyx obovatus. A sample treatment and preparation protocol that employs strict statistical treatment to ensure sample homogeneity was applied. As preliminary indicator of homogeneity, total nitrogen and phosphorus were determined and an iterative process using Levene test was applied to statistically test the homogeneity of the ground T. obovatus leaves. At p = 0.01, homogeneity of the plant material was achieved on the third ground sample. Among the six solvents used, methanol gave the best yield of extractable phytochemicals and a butylated hydroxytoluene-spike recovery of 77%, whereas diethyl ether gave the lowest yield and a butylated hydroxytoluene-spike recovery of 63%, suggesting that optimal yields tended to be favoured by more polar solvents.

Key words: Phenolic compound, antioxidant, Temnocalyx obovatus, homogeneity, Levene test, extraction yield.