Optimization of Cassava-Peel Derived Nanostarch Via Sulphuric Acid Hydrolysis Using Taguchi Method

Abstract

Untreated cassava peel waste generated during harvesting and processing poses significant environmental challenges. Synthesis of starch nanoparticles from cassava peels for various applications offers a sustainable solution to waste reduction and contributes to environmental conservation. The unique characteristics of nanostarch such as thermal stability, high solubility, non-toxicity, and low cost enable its application in the food industry, cosmetics, enhanced oil recovery, and textiles. The current study employed the Taguchi method design to optimize sulphuric acid hydrolysis in synthesizing cassava peel-derived nanostarch. Additionally, the derived cassava peel nanostarch was characterized using Fourier Transform Infrared Spectroscopy (FTIR). Starch was extracted from cassava peels, followed by synthesizing starch nanoparticles via sulphuric acid hydrolysis. Optimization of nanostarch synthesis was based on randomized experimental runs using the Taguchi method generated by the Minitab software, with the experiments conducted in duplicates. The optimum conditions for the experiment were found to be 3 hours, at 25°C using an H<sub>2</sub>SO<sub>4 </sub>acid concentration of 2M. These conditions produced a yield of 92.28%. ANOVA analysis identified sulphuric acid concentration as the most significant factor that affected cassava nanostarch yield, with p-values of 0.026 and 0.003 for the signal to noise (S/N) ratios and means, respectively. The least significant factor based on the analysis was the hydrolysis time. However, according to the S/N ratios main effect plot, the most optimum conditions predicted by the Taguchi method design was 9 hours, 25°C using H<sub>2</sub>SO<sub>4 </sub>acid concentration of 2M. A confirmation experiment conducted at 25°C, using an H<sub>2</sub>SO<sub>4 </sub>acid concentration of 2M for 9 hours gave a nanostarch yield of 97.01%. In conclusion, the Taguchi method design identified sulphuric acid concentration as the most significant factor in synthesizing cassava peel-derived nanostarch via acid hydrolysis.