Arabinoxylan Improves Quality and Inhibits Starch Retrogradation in Mashed Potatoes Under Cold Storage

Mashed potatoes (MP) are widely consumed starch-based foods. However, their shelf life is limited by starch retrogradation during low-temperature storage, which causes texture hardening, water exudation, and sensory deterioration. Although natural polysaccharides can modulate starch properties, the specific anti-retrogradation effect of soluble arabinoxylan (AX) in complex MP matrices remains unknown. In this study, the effects of AX on the physicochemical and sensory qualities of MP during 7 d of storage at 4 °C were comprehensively investigated. Results demonstrated that AX significantly reduced the rheological moduli (i.e., G′ and G″ values) and hardness of stored MP. Additionally, LF-NMR, XRD, FTIR and SEM analyses, together with water holding capacity (WHC) measurement, revealed that AX improved water retention and restricted water mobility of the system, delayed starch recrystallization, inhibited the formation of short-range ordered structures, and physically disrupted the starch microstructure, thereby attenuating the overall starch retrogradation process. Moreover, the addition of AX helped maintain the sensory appeal of the products. These findings suggest that AX modulates the structural evolution of the starch matrix during storage. This distinguishes the present work from conventional hydrocolloid studies by demonstrating that AX can simultaneously inhibit starch retrogradation, stabilize color, and maintain soft texture. This work highlights the potential of AX as a clean-label multifunctional modifier to extend the shelf life of starchy convenience foods.