Development of an analytical fluorescence method for quantifying β-glucan content from mushroom extracts; utilizing curcumin as a green chemical fluorophore

In this study, a β-glucan quantification method from mushrooms based on the fluorescence enhancement of interaction with curcumin was developed. Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) was used to confirm the interaction. Key factors, including pH, temperature, effect of salt, wavelength, and fluorophore ratio were optimized. The method was validated with curcumin concentrations of 4 ppm and 10 ppm to label β-glucan for the determination of extracted β-glucan ranges of 1–20 ppm and 20–60 ppm showing good accuracy (93.0–107.0 %) and precision (RSD < 2.0 %). The method performed linear response R² values of 0.9989 and 0.9968, the limit of detection (LOD) of 0.28 and 0.92 ppm, and limit of quantification (LOQ) of 1.52 and 5.06 ppm for 4 and 10 ppm curcumin concentration, respectively. At last, the results of the analysis of β-glucan in commercial Lentinula edodes and Lentinus squarrosulus were relatively comparable with common dye methods.