Evaluation of the Antioxidant Potential of Soursop (<em>Annona muricata</em> L.) Fruit at Different Maturity Stages

Abstract

Purpose: Different maturity stages and extraction methods of soursop fruit could affect the antioxidant activity of the fruit. The aim of the present study was to evaluate the antioxidant activity and phenolic content of soursop at four different maturity stages namely, Immature Stage (IM), Partially Mature Stage (PM), Fully Mature Stage (FM), and Well Ripened Stage (WR) using four extraction methods.Research Method: Sonication and maceration using a stir plate were used as extraction techniques, while absolute ethanol and 70% v/v ethanol were used as extraction solvents. The Ferric Reducing Antioxidant Power (FRAP) and DPPH radical scavenging activity were used to determine the antioxidant efficacy, while the Folin-Ceocalteu assay was used to determine the total phenolic content (TPC).Findings: From the analyses, the TPC, FRAP assay, and DPPH activity significantly (p<0.05) changed with the maturity stages. The highest TPC (165.67±2.86 mg GAE/g) was observed in the 70% ethanol extract of the WR stage with the sonication extraction method. The highest (p<0.05) FRAP value (393.91±4.23 µmol Fe+2/L) was observed in 70% ethanol extracts of FM with sonication extraction. The highest DPPH radical scavenging activity (IC50 60.13±0.18 ppm) was recorded in 70% ethanol extract of the WR stage with sonication extraction. TPC and antioxidant activity increased (p<0.05) as maturity progressed. Research Limitations: Time was limited to evaluate the IC50 values of the IM, PM, and FM stages.Originality/ Value: Soursop at the WR stage, extracted using 70% ethanol with sonication extraction, comprised a high phenolic content and thus, exhibited strong antioxidant activity. Therefore, the findings explore its potential as a health-promoting antioxidant source.