Enzimatically induced copigmentation in pomegranate juice concentrate during storage

The aim of this study was to enhance the colour and increase the colour stability of pomegranate juice concentrates (PJC) during storage at 4 and 20 degrees C by enzymatically inducing copigmentation. To this end, following were used: "tannin-acyl-hydrolase (TAH)," "TAH+paraoxonase-1 (PON-1)," "papain (P)" and "TAH+PON-1 + P." TAH-treated PJC exhibited a comparable level of anthocyanins to control group (p > 0.05). Although the amount of anthocyanin in PJCs treated with "TAH+PON-1 '' and "TAH+PON-1+papain" was similar (p > 0.05), the substances formed by "TAH+PON-1 '' increased colour density, whereas substances formed by "TAH+PON-1 + P" decreased due to the activity of "P." Before and after storage, the highest hyperchromic effect was observed in PJC treated with "TAH+PON-1." These results showed "TAH+PON-1 '' induced copigmentation. All anthocyanins, except pg-3,5-diglu, were involved in copigmentation with aspartic acid, prolamin, rutin, gallic acid and alpha-punicalagin. Storage at 4 degrees C led to greater stability of anthocyanins (up to 5-fold), hyperchromic effect (up to 13-fold) and colour density (up to 2-fold) than storage at 20 degrees C. Therefore, we recommend "TAH+PON-1" treatment and storage at 4 degrees C to produce PJC with high and stable colour values.