State/phase transitions induced by ice recrystallization and its influence on the mechanical properties of potatoes (Solanum tuberosum L.) var. Russet Brown

Thermal transitions in frozen foods may occur due to temperature fluctuations during storage and distribution, inducing ice recrystallization and loss of food quality. This study evaluated the effects of state/phase transitions on ice recrystallization and on mechanical properties of unblanched and blanched potatoes. Potato samples were frozen at −32 °C for 5 days to achieve a glassy state and then subjected to temperature fluctuations of varying amplitudes to achieve different physical states: glassy state with temperature fluctuation, rubbery and thawed states. Ice crystal size of potatoes was evaluated using scanning electron microscopy (SEM) through pore analysis of freeze-dried potatoes. Hardness of potatoes was determined using texture analyzer. Temperature fluctuation increased the ice crystal size and reduced the hardness of potatoes-the changes depended on the severity of temperature fluctuations and the treatment medium. Findings may inform improved packaging design, storage and transportation strategies to minimize quality changes in frozen potatoes. •Temperature fluctuations influenced ice crystal size distribution in frozen potatoes.•Temperature fluctuations reduced hardness in frozen thawed potatoes.•The degree of change depended on the severity of the temperature fluctuations.•Temperature fluctuations effects were more pronounced in unblanched potatoes.