A Novel Technique for the Extraction of Whiteness and Yellowness Indices of Sugar Based on Digital Color Imaging

The visual whiteness of sugar is a key factor in determining its quality and purity. Consequently, the development of rapid and cost-effective methods for the color evaluation of sugar samples is of critical importance to the sugar industry. This study aims to introduce a method for the measurement of whiteness index (WI) and yellowness index (YI) of sugar based on a commercial digital scanner. In this regard, sugar samples were collected across three different cultivation seasons. The color images of sugar samples were obtained using a digital scanner, and the color indices were extracted based on four WI and two YI formulas. The results were then compared with the standard color measurement technique based on spectrophotometry. It was observed that the proposed technique led to a correlation coefficient of 0.947 for the estimation of WI. For both YI formulas, the correlation of 0.944 was obtained. The results indicate that the proposed technique has a remarkable performance in the estimation of sugar color indices and offers a simple, easy-to-implement and fast technique for industry.