EXTRACTION OPTIMIZATION OF THREE INDEPENDENT VARIABLES OF ANTIOXIDANTS FROM BASIL LEAVES USING RESPONSE SURFACE METHODOLOGY

The current study reports the antioxidant activity of Ocimum basilicum. Central composite design (CCD) was used to study the effect of variables on the extraction using magnetic stirrer (MST). Three independent variables including temperature, extraction speed, and extraction time were studied that optimize particular responses of total phenolic content, ferric reducing antioxidant power (FRAP), and DPPH free radical scavenging activity. The effect of the extraction temperature on extraction process was investigated in the range from 26.3oC to 93.6oC, extraction time, from 1 to 30 h, and extraction speed, in the range from 263 to 936 rpm. The extraction yield was significantly (P < 0.05) affected by all the variables. Temperature and extraction speed were found to have a marked effect while the extraction time was found to have possible minor effects. Graphical optimization determined the optimum conditions for the extraction. The optimum condition predicted an extraction yield of 20.49g/100g at 75.33oC for five hours at 73 rpm. Optimum conditions were determined to obtain highest extraction yield. Results showed that water/seed ratio was the most significant parameter, followed by temperature and time. All quantitative modeling and response surface methodology recommended that extraction temperature and time were the most effective parameters of MST process. However, extraction time was found out to be an insignificant factor in MST extraction of antioxidant and total phenolic compounds of O. basilicum.