Optimization of blanching condition for removing potassium from spinach using response surface methodology

Spinach is the one of the important leafy vegetables which can be used in various dishes, but its high potassium content is a limitation for use in meal for chronic kidney disease (CKD) patients. This study aimed to optimize the blanching conditions for spinach with high potassium reduction rate as well as good hardness and color using response surface methodology (RSM). A central composite design (CCD) was employed with encompassing blanching temperatures ranging from 80 to 100 °C and blanching times from 2 to 4 min, respectively. Elevated blanching temperatures and prolonged blanching times correlated with increased potassium reduction rate and a* value, while concurrently resulting in diminished hardness and L value. The analysis revealed that the optimal condition entailed a blanching temperature of 98.28 °C and a blanching time of 2.77 min. Optimized blanching conditions for spinach in this study promise for diversifying the dietary options of CKD patients.