Comparative study on DPPH radical scavenging capacities of lemon juice based on two methods

The DPPH radical scavenging capacities of California lemon juice and Guangxi lemon juice were determined using electron paramagnetic resonance (EPR) and ultraviolet-visible spectroscopy (UV-Vis) . The EC50 values for California and Guangxi lemon juice measured by EPR method were 54.53% and 32.73%, respectively, and the corresponding vales measured by UV-Vis method were 46.41% and 30.41%, respectively. The study revealed good positive correlation between DPPH radical scavenging rate and lemon juice concentration. In addition, statistical analysis indicated that the results were not significantly influenced by methods. In conclusion, both the two methods could be used for analysis of DPPH radical scavenging capacities of lemon juice.