Simultaneous quantification of fructose and sucrose in beverages using microfluidic paper chip and colorimetric...

Excessive sugar intake, particularly from fructose and sucrose, is associated with a variety of severe health problems, including obesity, type 2 diabetes, and cardiovascular diseases. Accordingly, this study presents a rapid and efficient method for quantifying the fructose and sucrose concentrations in beverages using a microfluidic paper-based analytical device (μPAD) with a pixel-area image processing method. The μPAD is embedded with two reagents, phenol-acetone-boric acid reagent (PABR) and phenol-acetone reagent (PAR), in separate detection zones to facilitate the simultaneous detection of fructose and sucrose, respectively. When exposed to a beverage sample and heated at 37 °C for 6 min, the two reagents react with the sugar content in the presence of sulfuric acid to generate magenta complexes. The complex's red, green, and blue signal intensities are then analyzed using self-written software to determine the corresponding fructose and sucrose concentrations based on a pixel-area calibration curve obtained previously in colorimetric testing. The device detects fructose and sucrose along with a linear response. In the experimental operating range of 20-80 mM, the device provides a linear response for joint fructose/sucrose detection. The mean blank signal plus three times the standard deviation was used to determine the estimated limits of detection (LODs), which were 2.8 mM for fructose and 4.2 mM for sucrose. The correlation coefficient was R² = 0.9909. Moreover, validation experiments performed using high-performance liquid chromatography (HPLC) show a detection error of less than 6.0 % and a recovery rate exceeding 94.7 % for ten commercial beverages. The proposed approach thus provides a promising method for various applications in food quality monitoring and sugar quantification in the beverage industry.