Rational design of a starch/whey protein isolate/caffeic acid ternary system to alleviate gel deterioration during freeze-thaw cycles

To strengthen starch gel quality and improve the deterioration from freeze-thaw cycles, corn starch/whey protein isolate (WPI)/caffeic acid (CA) composite gels were rationally constructed in this study. The results showed that the introduction of WPI and CA significantly optimized the microstructure of the gels, an observation verified by SEM and CLSM. In addition, FT-IR and XRD analyses further revealed that the interaction mechanism within the composite gel was mainly due to the reinforcement of hydrogen bonds. Notably, the introduction of WPI and CA resulted in a decreasing trend in the viscosity of the system. Meanwhile, the test results of rheological properties, stress-strain response, and textural properties indicated that the simultaneous introduction of WPI and CA led to the softening of the gel texture. After undergoing freeze-thaw cycles, the composite gels showed a positive water distribution pattern, water holding capacity, and color improvements. These findings are important references for guiding the development of starch-based gel-based foods and optimizing their freeze-thaw stability and texture regulation strategies.