Roasting oat-based paste modulates postprandial glucose and insulin sensitivity: Roles of acrylamide, texture, and starch fractions.

Oat-based foods are widely recommended for dysphagia management and glycemic control, yet the impact of roasting conditions on their health benefits remains unclear. This study compared the postprandial glycemic and insulinemic responses to oat pastes prepared from low-temperature (90-110 °C) and conventional high-temperature (160 °C) roasted oat flours, using refined rice (R) as a reference, in a randomized crossover trial involving 21 healthy young female adults. All oat pastes complied with Level 3 dysphagia safety standards as defined by the International Dysphagia Diet Standardisation Initiative (IDDSI). Results showed that low-temperature roasted oats (L0 and L40) elicited significantly lower postprandial glucose responses than high-temperature roasted oats (H30) and R did, while H30 induced comparable glycemic but higher insulinemic responses than R did. Notably, H30 exhibited impaired insulin sensitivity (higher HOMA-PP) and adverse second-meal effects, likely due to acrylamide formation (507.4 μg/kg) and reduced slowly digestible starch (SDS). In contrast, low-temperature roasting preserved β-glucan integrity, enhanced SDS and resistant starch (RS) content, and improved textural properties without detectable acrylamide. These results demonstrate that optimizing roasting temperatures can mitigate adverse metabolic effects while maintaining swallowing safety, offering critical insights for developing functional foods for elderly and dysphagic populations with specific glycemic management needs.