Influence of amino acid addition on the thermal stability of anthocyanins in pomegranate (Punica granatum L., cv. Hicaznar) and orange (Citrus sinensis L. Osbeck, cv. Valencia) juice blend

•Orange juice decreased stabilities of individual anthocyanins in pomegranate juice.•Aspartic acid increased (4.3 times) stability of cyanidin-3,5-diglucoside at 90 °C.•Interaction between proline and pelargonidin-3,5-diglucoside at 90 ℃ was copigmentation.•Valine showed copigmentation effect on delphinidin based anthocyanins at 105 °C.•Copigmentation with amino acids protected anthocyanins against ascorbic acid.