Effects of Different Solvents and their Purity on the Extraction of Total Phenolic Content, Total Flavonoid Content and Antioxidant Activity from the Peels of Lotkon (Baccaurea Motleyana Müll. Arg.) and Longan (Dimocarpus Longan Lour.)

The objectives of this study was to investigate how three types of solvent (ethanol, methanol, and acetone) affected the yield of total phenolic content (TPC), total flavonoids content (TFC) and DPPH radical scavenging activity of extracts from lotkon and longan peels. The results showed that the 50% methanol extracts for longan peel displayed the highest levels of TPC, TFC, and DPPH free radical scavenging activities. The TPC varied for both peel extracts (longan and lotkon) from 343.39±0.22j to 425.55±0.19a, 121.63±0.29j to 321.54±0.12a mg GAE/100g dry weight; TFC from 48.24±0.09j to 86.24±0.11a , 6.47±0.37g to 15.37±0.11a mg QE/100g dry weight and DPPH radical scavenging activity from 30.79±0.03j to 60.01±0.02a %,25.84±0.01j to 54.76±0.03a % respectively. These findings showed that total phenolic, total flavonoid and antioxidant activity of lotkon and longan peel extracts are significantly influenced by the extraction solvents and their purity. The findings of this study serve as a valuable guide for the food sector in determining the ideal conditions for extracting antioxidants and desirable phenolic compounds from lotkon and longan peels, as well as a solid foundation for more research in the future.