Mechanistic insights into starch behavior and starch-protein interactions in whole grain oat flour: Structural and
1State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China.
Abstract:
This study explores the effects of steaming, roasting, and steam explosion treatment on the structural, rheological, and functional properties of whole grain oat flour, with a particular focus on starch changes and starch-protein interactions. Steam explosion treatment altered the physicochemical properties of whole grain oat flour, evidenced by changes in color parameters (L* from 70.9 to 67.4, WI from 58.6 to 54.4), degree of gelatinization (increased from 21.4 % to 89.9 %), and gel network stability. Notably, steam explosion treatment uniquely disrupted starch crystallinity and reduced amylopectin content (40.8 % to 31.1 %). Microscopic analysis (scanning electron microscopy, confocal laser scanning microscopy) and multi-scale structural characterization (infrared spectroscopy, differential scanning calorimetry) revealed that the oat starch-protein mixture exhibited a three-dimensional cellular network, with significantly increased hydrogen bonding between starch and protein. This interaction formed a cross-linked gel network structure, enhancing gel strength, water retention, and thermal stability while delaying starch retrogradation, ultimately improving the shelf life of oatmeal porridge. Mechanistic analysis revealed that steam explosion treatment enhanced water molecule binding to macromolecules, mitigating water migration and structural degradation during storage. This research provides new insights into the molecular interactions underpinning whole oat processing, offering a foundation for the development of high-quality whole oat-based products.
