The effect of extraction conditions using ultrasonic and maceration methods on the extraction rate of phenolic compounds and the extraction efficiency of jujube fruit (Ziziphus spp.)

Background: Plants are among the most important sources of phenolic compounds, which also include natural antioxidants. The aim of this study was to investigate the effect of two methods of extraction by ultrasonic bath and maceration on the extraction of phenolic compounds from jujube fruit using water and 80% ethanol solvents. Methods: In the ultrasonic bath method, water and 80% ethanol solvents were used in three time levels of 15, 30 and 60 minutes and two temperature levels of 50 and 70 °C. In the maceration method, water and 80% ethanol solvents and their combinations were used and the content of phenolic compounds using the Folin-Ciocalteu method and the extraction efficiency of the extracts were determined. Results: Based on the results of ultrasonic bath extraction method, 80% ethanol solvent, 60 minutes and 50 °C extracted the highest content of phenolic compounds (86.33 mg GAE/100 g of dry sample) from the fruit and the extraction efficiency of its extract was 95.66%. In the maceration extraction method, 80% ethanol solvent extracted the highest content of phenolic compounds (61.40 mg GAE/100 g of dry sample) and the extraction efficiency of the extract was 77%. Conclusion: According to the results of both methods, the content of extraction of bioactive compounds based on the type of solvent, temperature and time were significantly different and 80% ethanol solvent was the best solvent for the extraction of compounds. Ultrasonic extraction had a significant effect on the extraction of phenolic compounds of jujube fruit.