Enzimatically induced copigmentation in pomegranate juice concentrate during storage

• TAH+PON-1 caused the highest hyperchromic effect and increased colour density • Storage at 4°C increased the copigmentation (C) stability by 13 times. • Papain” inhibited the participation of 3-glucosidic anthocyanins (ACNs) in C. • Hydrolysis of tannins by “TAH+PON-1” led to C with all ACNs except pg-3,5-diglu • PJC treated with “TAH+PON-1” should be stored at 4°C to maximise quality 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°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 α-punicalagin. Storage at 4°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°C. Therefore, we recommend "TAH+PON-1” treatment and storage at 4°C to produce PJC with high and stable colour values.