Abstract
This study aimed to establish optimal double-cooking condition using response surface methodology that maintained hardness while maximizing potassium reduction rate. The experimental design was based on the first cooking time (4.5-5.5 min) and rinsing time (20-60 s) through central composite design. This study suggested an optimal double-cooking condition of 5.5 min for first cooking and 57.57 s for rinsing. The model corroborated that the double-cooking condition significantly influenced dependent variables, including potassium reduction rate, hardness, and color (b-value). As the first cooking time increased, the potassium reduction rate increased and the hardness and b-value decreased. SEM revealed that double-cooked potato had more organized and netted structure. This structure could be helpful to maintain hardness, but relatively large amount of potassium could be leached out. The established optimal double-cooking condition for potatoes holds promise for broadening the dietary options for chronic kidney disease patients.