Comparison of different extraction methods on antioxidant properties from Ocimum basilicum Linn extract

Abstract

Extraction methods are important to promote the amount of antioxidant properties in herbal plant. The present study was done to evaluate the antioxidant properties of Ocimum basilicum L. plant. Extraction was conducted on different plant parts of O. basilicum L. such as leaves, flower and stem parts by using different extraction methods (solvent extraction with waterbath shaker, maceration and soxhlet extraction). The highest recovery of total phenolic content (TPC) of 10.42 ± 0.14 mg GAE/ g of sample and 69.22 ± 0.18 % of antioxidant activity was obtained from the flower extract by using the solvent extraction with waterbath shaker. Thus, the waterbath shaker was chosen be utilised in the following screening and optimisation process on the O. basilicum L. flower. All the extraction parameters such as extraction time, extraction temperature and agitation speed showed significant effect (p < 0.05) on the antioxidant properties of O. basilicum L. flower extracts in the one-factor-at-a-time (OFAT) screening method. The best extraction conditions in the screening process was used as a zero level of optimisation process by using Response Surface Methodology (RSM) coupled with Central Composite Design (CCD). The maximum antioxidant activity of 79.58 % was obtained when the optimum extraction conditions were at 88 minutes of extraction time, 65.4 °C of extraction temperature and 83 rpm of agitation speed. Besides that, the quadratic model was suggested as the most appropriate model. The “Lack of Fit F-value” of 3.10 indicated the model is well fitted to the data. The validation test verified the reliability of the experimental extraction conditions.