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

## TL;DR

Whole Apios gel is better than starch gel, and adding oil improves its stability and texture.

## Contribution

Demonstrated that whole Apios gel outperforms starch gel and that oil addition inhibits retrogradation effectively.

## Key findings

- Whole Apios gel had lower syneresis and better texture than starch gel.
- Adding 4% oil reduced hardness, improved elasticity, and inhibited retrogradation optimally.
- Oil incorporation decreased hydrogen bonding and recrystallization in the gel.

## Abstract

Apios americana 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.

Whole Apios gel demonstrated superior quality characteristics compared to Apios starch gel, including lower syneresis and improved sensory preference due to its nutrient‐rich composition. The addition of oil effectively inhibited retrogradation, with 4% oil achieving optimal textural stability, reduced enthalpy change (ΔH), and decreased hydrogen bonding intensity. These findings indicate the potential of whole Apios gel as a functional and stable gelling food product without starch extraction.