Comparison of Extraction Methods on Total Phenolic and Antioxidant Activity of Cassava Peel

Cassava (Manihot esculenta Crantz) peel is an agricultural by-product rich in secondary metabolites with potential antioxidant properties. However, traditional extraction methods such as maceration often require significant labour, making it necessary to evaluate modern approaches such as Ultrasonic-Assisted Extraction (UAE) to enhance extraction yields. This study evaluated and compared maceration and UAE techniques for extracting cassava peel, focusing on Total Phenolic Content (TPC) and antioxidant efficacy. Cassava peel was extracted using 70% ethanol. The Folin-Ciocalteu method was used to determine TPC, whilst the 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical scavenging assay was used to assess antioxidant activity. The results showed that UAE yielded a higher TPC, at 46.14 mg gallic acid equivalent/g, compared with the maceration technique, which yielded 45.81 mg gallic acid equivalent/g. Furthermore, the UAE extract demonstrated greater antioxidant capacity, with a lower half-maximal Inhibitory Concentration (IC50) value of 23.43 ppm, compared with 39.32 ppm for the maceration extract. Mann-Whitney U test showed no significant difference in TPC between the two extraction techniques. Meanwhile, an independent t-test showed a significant difference in antioxidant activity (p<0.05). In conclusion, UAE is an efficient technique for obtaining cassava peel extract with greater antioxidant properties.