Optimization and validation of a smartphone-based method for the determination of total sterols in selected vegetable oils by digital image colorimetry

Abstract

This study aimed to optimize and validate a smartphone-based method to determine the total sterols content in edible vegetable oils by digital image colorimetry (DIC). The spectrophotometric method was used as a reference for comparison. Better linearity was obtained using blue (B) values from red, green, and blue (RGB) with a mean R² of 0.96 and a standard error close to that of the spectrophotometric method. The relative standard deviations were less than 14.0% for the repeatability and approximately 10.0% in terms of intermediate precision. The apparent recovery ranged from 91.6% to 107.9%. The limits of detection and quantification were 6.49 mg 100 g−1 and 34.82 mg 100 g−1, respectively. The smartphone-based DIC performed similarly to spectrophotometry in the determination of total sterols in vegetable oils using the Liebermann-Burchard colorimetric method.