Whey protein improves the stability of C-phycocyanin in acidified conditions during light storage

C‐phycocyanin is a bright blue natural colorant used in food and beverage applications. However, its color stability poor acidic conditions under exposure to light. In this work, we study the use of whey protein isolate (WPI) protect from degradation. Low concentration (0.05–0.1%) WPI addition delayed (~2 days) degradation at pH 3.0 over 5-day storage was aggravated adversely during light when mixed with higher (~1%) degraded after heat-treatment. The Fourier transform infrared fluorescence spectroscopy confirmed that structural changes (e.g., alpha-helix protection transformation beta-sheet) due interaction WPI. These results, along quartz crystal microbalance dissipation technology outcomes, suggest low may help C-phycocyanin’s secondary structure becoming damaged storage, preventing