Effect of Extrusion Temperature on the Microstructural Changes and Cooking Quality of Whole Highland Barley Noodles

ABSTRACT

To address the textural defects of whole highland barley noodles caused by the lack of gluten proteins, this study employed twin‐screw extrusion technology to prepare whole highland barley noodles and investigated the effects of core zone extrusion temperatures (90°C, 100°C, 110°C, 120°C, and 130°C) on the physicochemical properties of the noodles. The results demonstrated that when the core zone temperature was ≤100°C, the noodles exhibited smooth surfaces, compact internal structures with minimal air bubbles, and significantly reduced starch molecular weight. Extrusion processing induced the fragmentation of amylopectin while promoting the formation of short‐chain starch molecules. Additionally, extrusion disrupted the ordered structure and double‐helix configuration of highland barley starch, transforming its crystalline structure from A‐type to amorphous V‐type, and increased the retrogradation strength. Microstructural analysis confirmed that extrusion treatment induced morphological reshaping of starch granules, exacerbated starch fragmentation, and enhanced starch aggregation. Notably, proteins formed tight cross‐linked structures with starch during the process. Overall, a core zone temperature of 100°C was identified as the optimal condition for producing whole‐barley noodles, resulting in the lowest breakage rate and cooking loss while maintaining structural integrity. Under this condition, partial gelatinization and starch‐protein cross‐linking synergistically improved water‐binding capacity and thermal stability. This study provides molecular mechanisms and processing parameters for optimizing extrusion‐based highland barley noodle production, offering a scientific basis for industrial applications.