Drying Method–Dependent Alterations in Protein Structure, Gastrointestinal Digestibility, and Peptide Profiles in Penaeus vannamei
Abstract
This study evaluated the effects of different drying methods on the protein structure, digestive behavior, and peptide profiles of Penaeus vannamei. Shrimp samples were processed by hot air drying (HAD), vacuum freeze-drying (VFD), microwave drying (MD), and natural air drying (NAD), followed by in vitro simulated gastrointestinal digestion. The results showed that protein digestibility differed among drying treatments, following the order NAD > HAD > VFD > MD. Differences in digestive behavior were closely associated with structural changes caused by drying. During digestion, protein structures were gradually disrupted, as evidenced by reduced particle size and electrophoretic band intensity, increased surface hydrophobicity and intrinsic fluorescence, decreased β-sheet content, and increased β-turn content. Peptide profiling further demonstrated that NAD treatments promoted the release of peptides (2975 peptides) after gastrointestinal digestion. These findings provide mechanistic insights for the rational design of nutritionally optimized dried shrimp products.