Unveiling the inhibitory effect of curcumin on phycocyanin glycation, with insights into its application in spirulina biscuits

Studies on the glycation of phycocyanin (PC) and its inhibition mechanism are scarce. This study aimed to explore the glycation of PC during thermal processing and elucidate the potential inhibitory effect of curcumin (Cur) on this process. The results demonstrated that Cur (1 mg/mL) significantly inhibited the formation of fructosamine (73.9%), dicarbonyl compounds (44.6%-59.3%), and advanced glycation end-products (AGEs) (50.6%). Cur also effectively prevented protein oxidation (>50%) and sulfhydryl depletion (89.8%). Moreover, isothermal titration calorimetry (ITC) and molecular docking demonstrated the weak binding affinity between Cur and PC. The antiglycation mechanism of Cur mainly relied on trapping active carbonyl intermediates and enhancing antioxidant capacity rather than substantial binding to PC. Furthermore, Cur dose-dependently inhibited the accumulation of AGEs, 5-hydroxymethylfurfural, and dicarbonyl compounds in spirulina biscuits and markedly elevated the antioxidant capacity. These findings offer theoretical insights into the inhibition of AGE formation during the thermal processing of microalgae-based food products.