Impact of lipid modification on the structural and digestive properties of starch in cooked chestnut paste: A comparative study of butter and soybean oil.

Lipids are commonly added to starchy foods to improve both their sensory attributes and nutritional value. This study investigated the regulatory mechanisms of butter and soybean oil on the starch structure and digestibility in cooked chestnut paste (CCP). X-ray diffraction and complexing indices revealed the formation of V-type crystalline complexes, with soybean oil exhibiting a stronger complexation capacity due to its the flexible properties of unsaturated fatty acids. Soybean oil was more effective than butter in reducing starch digestibility and delaying the retrogradation of CCP. The Pearson correlation analysis revealed that lipid modification plays a significant role in regulating enzymatic hydrolysis rates by facilitating the formation of key structural domains. Moreover, the incorporation of soybean oil rather than butter significantly improved the textural properties (e.g. hardness and chewiness) of CCP. Rheological analyses demonstrated that the addition of edible oils decreased the viscoelastic modulus of CCP. These findings offer valuable insights into the crucial role of lipid modification in the design of starch-based foods with reduced digestibility.