Effect of different thermal processing methods on the edible quality and flavor profile of kidney bean and clam soup

Abstract

This study investigated how boiling, steaming, and stewing affect the flavor profile of kidney bean and clam soup to enhance its acceptability. We analyzed color, thiobarbituric acid reactive substances (TBARSs), free amino acids, flavor-presenting nucleotides, and volatile compounds using analytical techniques including GC-IMS, electronic nose, and electronic tongue. The boiled soup exhibited the highest levels of total free amino acids (1.3775 mg mL⁻¹) and the flavor-presenting nucleotide (IMP 39.447 ng g⁻¹). GC-IMS identified 3-methylthiopropanal, furfural, ethyl acetate, and 3-methylbutanal as the dominant volatile flavor compounds formed during thermal processing. Electronic nose/tongue data indicated that steaming and stewing generated higher concentrations of these key volatiles and enhanced overall aroma and taste complexity. Boiling preferentially increased umami-related precursors (amino acids/IMP), while steaming and stewing promoted the formation of characteristic aroma volatiles. This demonstrates that the thermal processing method significantly directs the flavor development pathway in kidney bean and clam soup.