Optimization of sodium metabisulfite concentration and drying temperature to enhance the quality of breadfruit starch using response surface methodology

Breadfruit ( Artocarpus altilis ) is an underutilized tropical crop widely cultivated in Indonesia, offering considerable potential as a sustainable source of starch for food applications. However, the quality of breadfruit starch is highly influenced by processing conditions. This study aimed to optimize sodium metabisulfite concentration and drying temperature to improve the yield (Y1) of breadfruit starch using Response Surface Methodology (RSM). A Central Composite Design (CCD) with two factors, sodium metabisulfite concentration (X1: 0.2–0.5%) and drying temperature (X2: 50–70 °C), was applied, resulting in 14 experimental runs. The quadratic model provided the best fit to describe the effects of sodium metabisulfite concentration and drying temperature on starch yield. At the optimum conditions of 0.324% sodium metabisulfite and 62.75°C drying temperature, the model predicted a starch yield of 6.164% with a desirability level of 0.922. These predictions were experimentally validated, yielding 6.119% respectively. The close agreement between predicted and observed values highlighted the effectiveness of RSM in optimizing processing parameters to improve breadfruit starch quality. This work delivers a robust optimization framework that directly supports future research on process scale-up, functional refinement, and the broader industrial deployment of breadfruit starch.