The production of grape juice concentrate on an industrial scale was evaluated and samples from the
main steps of processing have been collected and analyzed. The sampling steps included the selection
and washing of grapes (Nevsehir Patlak variety), pressing in order to obtain the juice separate from
the seed and the skin fraction, pasteurization, clarification, filtration, evaporation, and filling-packing
at 27 C with a Brix of 45. Samples from each of the processing steps were analyzed by a number of spectrophotometric
analyses. A series of anthocyanin compounds was identified using HPLC-MS, and the fate
of anthocyanins, quercetin rutinoside and procyanidins was followed using HPLC. The results indicate
that the removal of seed and fruit skin removes most of the procyanidins and anthocyanins, while
subsequent clarification and filtration treatments further reduce the anthocyanin content.