Quality Comparison of Apios Starch Gel and Whole Apios Gel and Effect of Oil Addition on Retrogradation Inhibition in Whole Apios Gel

<i>Apios americana</i> is an underutilized legume rich in carbohydrates, proteins, and micronutrients, yet research on its potential as a gel-based food and its retrogradation behavior remains limited. This study aimed to compare the physicochemical and sensory properties of gels prepared from whole Apios and Apios starch, and to investigate the effect of oil addition on retrogradation inhibition in whole Apios gel. Texture profile analysis, syneresis rate measurement, sensory evaluation, Differential Scanning Calorimetry (DSC), and Fourier Transform Infrared Spectroscopy (FTIR) were conducted to analyze gel characteristics and structural changes. Whole Apios gel showed significantly lower syneresis and superior texture acceptability compared with starch gel, receiving the highest overall liking score. Increasing oil content (0%-6%) decreased hardness, improved elasticity, and effectively reduced syneresis. DSC results indicated the lowest enthalpy value at 4% oil addition, demonstrating optimal retrogradation inhibition. FTIR analysis confirmed reduced hydrogen bonding and recrystallization, supporting the stabilizing mechanism of oil incorporation. These findings highlight the functional potential of whole Apios gel as a retrogradation-resistant gel product and suggest practical applications for value-added product development utilizing underused crops in the food industry.