In Vitro Digestion Analysis of Soft Candy Containing Peptide-Zinc Chelate Derived from Low-Fluoride Protein Hydrolysates of Antarctic Krill (Euphausia Superba)

The objective of this study was to develop soft candy with low-fluorine (26.57 ± 3.15 mg/kg) Antarctic krill peptides (AKP), by incorporating them with zinc (SC-AKP-Zn). Results showed that a 1:1 ratio of alkaline protease and flavored protease was the most effective enzyme combination, with optimized parameters including enzyme addition of 4000 U/g, pH 7.5, and a digestion time of 3 h. Ceramic membrane microfiltration could significantly increase AKP protein content. Chelation of zinc with AKP caused notable changes in structure, composition, molecular weight distribution, amino acid composition, microstructure, and surface elemental compositions. Moreover, The chelate of zinc-peptides in Antarctic krill (AKP-Zn) and SC-AKP-Zn showed superior stability compared to zinc sulfate and zinc gluconate under different pH and simulated digestion conditions. These findings provide a scientific basis for developing zinc-enriched ready-to-eat food products and highlight the potential of Antarctic krill meal protein resources in the food industry.