Effects of partially hydrolyzed guar gum on improving the quality of cooked rice during refrigerated storage

This study investigated the inhibitory effect of partially hydrolyzed guar gum (PHGG) on starch retrogradation and the quality of cooked rice during refrigerated storage. PHGG was incorporated at different concentrations into cooked rice, and its impact on moisture retention, textural properties, water mobility, crystalline structure, and retrogradation enthalpy was evaluated. PHGG-treated samples exhibited improved moisture retention and reduced hardness increase during storage compared with the control. Magnetic resonance imaging showed higher T 2 relaxation times in PHGG-treated rice, indicating greater water mobility. X-ray diffraction and differential scanning calorimetry analyses revealed lower crystalline order and reduced retrogradation enthalpy in the presence of PHGG. These results suggest that PHGG influences water distribution and limits starch molecular reassociation during storage, thereby contributing to improved textural stability. Among the tested conditions, PHGG at 3% provided a balance between texture modification and sensory acceptability. PHGG shows potential as a functional ingredient for improving the quality of cooked rice during short-term refrigerated storage.