The procedure employed
to determine total vitamin C was the reduction of dehydroascorbic
acid to ascorbic acid, using DL-dithiothreitol as a reducing
reagent, according to a modification of the procedure of other
authors (Sánchez-Mata, Cámara-Hurtado, Díez-Marqués, & TorijaIsasa,
2000). Sample (15 g) was homogenised with 40 ml of extraction
solution (3% meta-phosphoric acid plus 8% acetic acid)