Figure 2.

Effect of pH on extraction efficiency. Limonin (A) and hesperidin (B) concentrations in the ethanolic-aqueous extracts of lime peel after extraction with 60% (●), 70% (■), 80% (▲), and 100% (▼) ethanol in water with the specified pH values at 50 °C for 100 min. The statistical differences were separately analyzed for limonin and hesperidin by using one-way ANOVA followed by Tukey’s multiple comparisons test. * , **, *** and **** mean p < 0.05, <0.01, <0.001 and <0.0001, respectively, compared with the concentrations of limonin or hesperidin at pH 7 of each specified condition.