Interactions of blueberry anthocyanins with whey protein isolate and bovine serum protein: Color stability, antioxidant activity, in vitro simulation, and protein functionality

The interaction of proteins with anthocyanins (ACNs) gives rise to significant improvements in their functional properties. To explore the interactions between whey protein isolate (WPI)/bovine serum albumin (BSA) and blueberry ACNs, light (5000 Lux, 7 days), heat (85 °C, 2 h), sucrose (0.25 mg/mL), and vitamin C (0.15 mg/mL) were used to accelerate the degradation of ACNs. Through the observation of color changes and variations in the free radical scavenging rates, WPI and BSA were found to protect the ACNs to varying degrees. Moreover, WPI/BSA exhibited increased solubilities, foaming and emulsifying properties, and changed thermal stabilities and protein structures, in addition to decreased surface hydrophobicities and zeta potentials. Furthermore, the addition of WPI/BSA increased the number of ACN monomers in a simulated digestion system, as determined by high-performance liquid chromatography-mass spectrometry. Therefore, by studying the interactions between proteins and ACNs, we can provide a strategy and theoretical basis for determining the steady-state of ACNs in blueberry products.