Optimization of Extraction Process of Polyphenols from Annona squamosa Leaves and Its Antioxidant Activity in Vitro

In this experiment,the raw material was Annona squamosa leaves,and the polyphenol substances in the leaves were extracted by using ethanol solvent. The effects of ethanol volume fraction,extraction temperature,liquid-solid ratio and extraction time on the polyphenol extraction amount were respectively compared. The Box-Benhnken center combination test in response surface methodology was used to determine the optimal extraction process. DPPH radical and hydroxyl radical(·OH)methods were used to study the antioxidant activity of polyphenols from Annona squamosa leaves,and the scavenging ability of polyphenols from Annona squamosa leaves and ascorbic acid extracted under the optimal process conditions were compared. The results showed that when the volume fraction of ethanol was 55%,the ratio of liquid to solid was 50:1 (mL/g),the extraction time was 96 min,and the extraction temperature was 60 ℃,the extraction amount of polyphenol was the largest,reached(20.37±0.34) mg/g.The semi-inhibitory concentrations(IC₅₀)of polyphenols from Annona squamosa leaves on DPPH radical and hydroxyl radical(·OH)were 133.33 and 264.65 μg/mL respectively. The maximum scavenging rates of the samples in the test range were(51.34%±2.68%)and(52.50%±2.29%)respectively. In summary,the polyphenols from Annona squamosa had good antioxidant capacity and would provide theoretical basis for the development of polyphenols from Annona squamosa.