Automated determination of total polyphenols in apple juice

An automated method of total polyphenols analysis in apple juice using the Folin-Ciocalteu reagent is presented. Chlorogenic acid was selected as the standard since a similar kinetic behaviour, standard-sample, was observed. A straightforward method with good reproducibility (CV < 1%), sampling frequency (48 h-1) and correlation with the traditional batch method (r = 0.9924) is proposed.