Effects of Atmospheric Steam Treatment on Wheat Flour Gelatinization Degree, Coating Batter Rheology, and Crispness of Fried Crusts

This study investigates the effects of atmospheric steam treatment (AST) on wheat flours with varying gluten strengths (strong, medium, and weak) and their performance in frying batter applications. Wheat flours were steam-treated for 0-10 min and evaluated for gelatinization degree, water-holding capacity, microstructural changes, rheological behavior, and frying characteristics. The results indicated that the gelatinization degree and water‑holding capacity of wheat flours increased progressively with AST duration, reflecting the disruption of starch granule structure and enhancement of water absorption. These changes were further corroborated by scanning electron microscopy, which provided visual evidence of the gradual transformation of starch granules and the formation of a compact, interconnected network of gelatinized starch and denatured proteins. Rheological analysis revealed increased yield stress and apparent viscosity in AST batters, suggesting improved flow resistance and batter stability. Batters prepared with AST flours exhibited improved batter pick-up, sensory attributes, and enhanced crispness in the fried coatings. Optimal sensory performance for all three wheat flours was observed at a starch gelatinization degree of 50-55%. Within this optimal range, medium gluten flour exhibited the greatest improvements (peaking at 4-6 min) and produced fried coatings with the highest crispness, adhesion, and overall sensory acceptability. This performance may be attributed to its optimal consistency index (K) and flow index (n). These findings highlight AST as an effective clean-label method to improve wheat flour-based frying batters, offering valuable insights for selecting flour types and driving innovation in industrial frying applications.