Determination of yeast β-glucan content in composite yeast culture by enzymatic hydrolysis HPLC method

This study aims to establish a detection method based on enzymatic hydrolysis combined with high-performance liquid chromatography (HPLC) technology for the quantitative analysis of yeast β-glucan content in composite yeast cultures. The method employs exo-1,3-β-glucanase plus β-glucosidase (A1 enzyme) to enzymatically hydrolyze total glucans in the sample. Amyloglucosidase plus invertase (B1 enzyme) along with trehalase (B2 enzyme) are used to enzymatically hydrolyze α-glucans in the sample, and purified lichenase (C1 enzyme) and β-glucosidase (C2 enzyme) to hydrolyze the cereal β-glucans in the sample. The glucose produced after hydrolysis is subjected to PMP derivatization and detected by HPLC. By applying the formula, the results of the three types of glucan content were obtained, namely X_A, X_B, and X_C. Ultimately, the content of yeast β-glucan in the composite yeast culture was calculated as X_A - X_B - X_C. The experimental results showed that glucose exhibited good linearity within the concentration range of 1-400 μg/mL, with a correlation range of 0.99999, a detection limit of 0.084 mg/L, a quantification limit of 0.280 mg/L, an average spiked recovery rate of 80.857 % to 105.456 %, and an RSD of less than 5 %. These data indicate that the method established in this study has high precision and good feasibility, making it suitable for the detection and analysis of yeast β-glucan in composite yeast cultures.