Comparative Study on the Extraction and Quantification of Polyphenols from Moringa oleifera Leaves Using Maceration with Pulsed Electric Field (PEF) as Pretreatment and Microwave-Assisted Extraction (MAE)

Moringa oleifera leaves are rich in nutrients and bioactive compounds such as polyphenols which can be used as an antioxidant. Polyphenols of Moringa leaves can be extracted using conventional and non-conventional methods. This study compared maceration with Pulsed Electric Field (PEF) pretreatment and MAE method on extracting polyphenols from Moringa leaves. The performance of those methods was assessed based on the yield extracts, total polyphenol content (TPC), and antioxidant activity (IC50). The results showed that different methods significantly affected TPC and antioxidant activity. Maceration with PEF pretreatments obtained extracts with the highest TPC value (179.11 mg GAE/g) and antioxidant activity (33.56 ppm). In comparison, the MAE method produced TPC and antioxidant activity values of 22.64 mg GAE/g and 54.59 ppm, respectively. The yield extracts did not show differences significantly. Maceration with PEF pretreatment and MAE obtained the yield extract of 12.62% and 13.16%, respectively. Based on the results, it can be seen that maceration with PEF pretreatment has a better ability to increase TPC and antioxidant activity compared to the MAE method. Maceration with PEF pretreatment can increase TPC up to 7.9 times and antioxidant activity up to 1.6 times. This study showed the potential of PEF pretreatment in increasing yield and recovery of total polyphenol content and antioxidant activity of Moringa leaves extracts. Further study needs to be done focusing on optimization of extraction using maceration with PEF pretreatment characteristics, such as electric field strength, frequency, and exposure time.