Surimi soft gels for individuals with dysphagia were produced by enzymatic hydrolysis: Investigating the impact on the protein structure and its correlation with gel characteristics.

Dietary design for individuals with dysphagia has been widely concerned. We explored the feasibility of preparing surimi soft gels for individuals with dysphagia by adding alcalase, neutrase, papain, and bromelain (300-1200 U/g) and examined the relationship between gel characteristics and protein structure of samples. The results showed that the types and concentrations of proteases significantly influenced the gel properties and swallowing characteristics of surimi gels. The samples with 900 U/g papain complied with the Category II standards for dysphagia-adapted foods and Level 4 of the International Dysphagia Diet Standardization Initiative (IDDSI) framework, making them more suitable for people with dysphagia. Enzyme treatment induced shear-thinning behavior and enhanced water retention and wettability by increasing the proportion of bound water within the samples. Compared with the control group (surface hydrophobicity: 17.655 ± 0.056 μg, total sulfhydryl group: 8.078 ± 0.350 μmol/g, hydrogen bond: 0.725 ± 0.018 μg/mL), the samples with 900 U/g papain added showed significant changes in surface hydrophobicity (14.213 ± 1.037 μg), total sulfhydryl group (44.143 ± 0.876 μmol/g), and hydrogen bond (2.050 ± 0.233 μg/mL). These results indicated that changes in the gel properties of samples caused by enzyme treatment were closely related to the molecular structure. Texture analysis, IDDSI testing, and sensory evaluations further confirmed that protease-treated gels were appropriate for individuals with dysphagia. These findings provided insights into the preparation of surimi soft gels by enzymatic hydrolysis.