Development of a Size-Exclusion/Ion-Exclusion/Reversed-Phase Separation Method for the Simultaneous Determination of Inorganic and Organic Acids, Sugars, and Ethanol During Multiple Parallel Fermentation of Rice Wine

An effective method for monitoring the progress of rice wine fermentation (saccharification, glycolysis system, ethanol fermentation, and the TCA cycle) is required owing to the decreasing human resources in rice wine brewing and dramatically increasing export quantity of rice wine. This study aimed to develop an anion-exclusion/size-exclusion/reversed-phase chromatographic (AEC/SEC/RPC) separation protocol for the simultaneous determination of sugars, ethanol, inorganic, and organic acids for the effective monitoring of rice wine fermentation processes. Optimal chromatographic resolutions were obtained by the combination of a polymer-based size-exclusion column and H+-form weakly acidic cation-exchange resin column with a 20.0 mM phthalic acid eluent. The optimized AEC/SEC/RPC separation system determined 16 different species during rice wine fermentation in a single analysis. The developed AEC/SEC/RPC method demonstrated the below useful advantages for (1) evaluating the progress of rice wine fermentation; (2) evaluating the activity of brewing yeast from the behaviors of glucose, phosphate, and ethanol concentration; and (3) obtaining good correlation between the developed and official methods for monitoring glucose and ethanol. Consequently, several beneficial information was obtained for the process control of rice wine brewing by the developed method.