Pre-soaking pasta before cooking reduces energy consumption while producing distinct textural and digestive properties. However, the structural mechanisms governing these changes remain unclear. Therefore, this study aimed to elucidate these mechanisms using quantitative microscopy and examination of digestion kinetics in vitro. Microscopic image analysis revealed that pre-soaking induced pronounced spatial heterogeneity in starch distribution, with weakened surface gluten networks and expanded ungelatinized cores compared to standard cooking. Despite equivalent overall gelatinization, pre-soaked samples exhibited 10–18% faster digestion rates while maintaining similar equilibrium digestibility (84.8–86.3%). Among pre-soaked samples, strong correlations among surface color profiles (b values), cooking loss, adhesiveness, and digestion rate constant (r = −0.99) demonstrated that surface architecture, rather than bulk gelatinization, governs functional properties. These results suggest that pre-heating moisture distribution determines surface structure, which in turn controls both texture and starch digestibility, providing mechanistic insights for optimizing pasta preparation to achieve desired textural and glycemic outcomes.
Shibata-ishiwatari et al. (Thu,) studied this question.