How do pasteurisation parameters affect the colour stability of natural fruit juice concentrates in RTD beverages, particularly red and pink tones?

Pasteurisation itself at standard parameters (e.g. 70°C for 15 minutes via tunnel) should not change product colour. However, natural red pigments—particularly anthocyanins from strawberry and blackberry juice concentrates—can degrade under high heat or oxidation, potentially browning over time. Members have found several practical solutions: (1) Reduce pasteurisation temperature slightly and compensate with longer hold time to maintain the same pasteurisation unit; (2) Add ascorbic acid at 0.2g/L as an antioxidant to prevent oxidative browning; (3) Lower pH slightly, which stabilises anthocyanins; (4) Switch to more heat-stable natural colours—members recommend black carrot extract as the top option for pink-red tones, or EXBerry/GNT as premium suppliers of stable natural colours. Since your product is canned (not glass), light strike is not a concern. The ultimate factory validation method is heating the product in a dishwasher to test pasteurisation effect on colour stability.