Preparation and Characterization of Calcium Alginate-Whey Protein Isolate Composite Gel Embedded with Anthocyanins

Calcium alginate-whey protein isolate (CA-WPI) composite gel embedded with anthocyanins was prepared by in-situ release method using sodium alginate and whey protein isolate as raw materials. The raw materials were allocated to three treatments: CA-WPI both at room temperature, room temperature CA-heated WPI, and heated CA-heated WPI. The results showed that compared with the control CA gel, the addition of heated WPI reduced the dehydration shrinkage rate of the gel by 74.17% and increased the freeze-thaw stability by 36.37%. In addition, the linear viscoelastic region of the mixed gels was greatly extended, while the creep recovery rate was decreased. Compared with the control gel, the hardness of the composite gels decreased, the viscosity of the heated CA-heated WPI gel significantly increased to 0.68 mJ. The results of infrared spectroscopy and storage stability showed that the composite gels effectively encapsulated anthocyanins, and 85.01% of the anthocyanins embedded in the heated CA-heated WPI composite gel was retained after 15 days of storage at 25 ℃.