Fig. 5. Ferric reducing capacity (A) and copper chelating activity (B) of apple juices supplemented with different concentrations of onion solutions and heating. Ferric reducing capacity are indicated using representative data; (n = 6). Values expressed as means ± standard deviation; (n = 9). *, p < 0.05 versus unheated onion concentration at 0%. #, p < 0.05; ###, p < 0.001 versus heated onion concentration at 0%. $, p < 0.05 versus unheated group.