Detection of bacterial spoilage during wine alcoholic fermentation using ATR-MIR and MCR-ALS

A new methodology is proposed to describe the evolution of main chemical compounds grape must during wine alcoholic fermentation using Attenuated Total Reflectance Mid Infrared (ATR-MIR) spectra in combination with Multivariate Curve Resolution Alternating Least-Squares (MCR-ALS). In addition, we have developed a process control strategy detect differences between fermentations running under Normal Operation Conditions (NOC) and intentionally spoiled lactic acid bacteria at beginning (MLF) promote deviations from NOC. MCR-ALS models on these data showed good fit (R2 = 99.95% lack 2.31%). It was possible resolve spectral profiles relevant molecules involved process, including one related bacterial spoilage (lactic acid). MSPC charts were built based concentration obtained T2 Q statistics. Spoiled wines off-limit values for after 96 h, making it early stages fermentation. Thus, use ATR-MIR analysis shows great potential rapid state appearance undesired which allows winemaker apply corrective measures obtain final product.