A novel strategy was developed to embed retrograded short-chain amylose (RSCA) into calcium alginate (CA) at varying concentrations (0.25 %, 0.5 %, 0.75 %, 1 %, 1.5 %, and 2 %) through ion crosslinking, aimed at enhancing the content of heat-resistant RS. The concentration of sodium alginate (SA) significantly influenced the thickness of the CA shell, thereby affecting the structural characteristics, physicochemical properties, and digestibility of the resulting beads. As the SA concentration increased from 0.5 % to 2 %, the CA shell thickness expanded from 0.612 μm to 1.837 μm, becoming denser and limiting the infiltration of enzymatic liquids during digestion. The initial gelatinization temperature of the beads exceeded 100 °C, and the enthalpy value of the 2 % SA beads was 25.40 ± 0.17 J·g-1, indicating excellent thermal stability. After heat treatment, the crystallinity reached 90.50 %. The RS content of the 2 % SA beads was as high as 72.66 ± 0.15 %, with an estimated glycemic index of 54.72, classifying them as low-glycemic index foods. The heat-resistant RSCA@CA developed in this study shows significant potential for application in functional foods, particularly for individuals with obesity and diabetes.
Keywords: Debranched starch; Ion crosslinking; Resistant starch; Sodium alginate.
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