Fourier transform mid-infrared (FT-MIR) spectroscopy is a fast, accurate, and practical technique for the quantitative analysis of compounds during ethanol fermentation. However, it is very temperature sensitive. This study aimed to develop a methodology for the real-time monitoring of fed-batch ethanol fermentations, taking into account the thermal fluctuations in the industrial process (in the range 30–35 °C). The use of FT-MIR combined with partial least squares (PLS) regression was evaluated as a tool to quantify sucrose, glucose, fructose, ethanol, and glycerol. The PLS models, based on fermentations carried out at constant temperatures in the range from 26 to 36 °C, presented high correlation coefficients (R²) and low root-mean-square errors of cross-validation and prediction that were below 7% of the calibration ranges for all compounds. The good performance of the models demonstrated their suitability for accurate process monitoring, covering a wide range of thermal variations observed in industrial operations.

中文翻译：

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中红外光谱实时监测补料分批乙醇发酵的温度影响

傅里叶变换中红外（FT-MIR）光谱技术是一种快速，准确，实用的技术，可用于乙醇发酵过程中化合物的定量分析。但是，它对温度非常敏感。这项研究旨在开发一种实时监控补料分批乙醇发酵的方法，同时考虑到工业过程中的热波动（在30–35°C范围内）。使用FT-MIR结合偏最小二乘（PLS）回归作为量化蔗糖，葡萄糖，果糖，乙醇和甘油的工具。PLS模型基于在26至36°C的恒定温度下进行的发酵，具有较高的相关系数（R ²），并且交叉验证和预测的均方根误差低，所有化合物均低于校准范围的7％。模型的良好性能证明了它们适用于精确的过程监控，涵盖了在工业操作中观察到的各种热变化。