Finger millet starch extraction: Comparative analysis of solvent efficiency, yield, and colour attributes

Abstract

Finger millet, known for its exceptional nutritional profile, remains underutilized due to challenges in processing and limited research focus. This study aimed to standardise the isolation process of finger millet starch based on yield and colour attributes, crucial for its industrial applications. Finger millet grains were cleaned, and processed using both dry and wet milling methods, with steeping solutions of distilled water, 0.25% NaOH, and 0.5% Na2SO4. The starch was isolated through centrifugation and subsequently dried. The yield and color (L*, a*, b* values) of the starch were evaluated to find the better isolation process. Results revealed that the wet milling method with 0.25% NaOH steeping solution produced the highest starch yield of 55.05 ± 1.32% and the highest L* value of 89.85, indicating superior lightness and purity. The alkali-assisted method facilitated effective dehulling and bleaching, contributing to better starch characteristics. In contrast, the distilled water steeping solution resulted in the lowest yield and colour values. The study involved a comparative analysis of finger millet starch obtained using different steeping solutions and isolation methods. The starch isolation using the wet milling method with NaOH steeping emerged as the most effective approach. This refined protocol offers a standardized method for obtaining high-quality finger millet starch, enhancing its potential for use in various food and industrial applications. The findings underscore the significance of the isolation process in determining the yield and quality of starch, providing valuable insights for future research and industrial practices.