Phenolic compounds play a critical role in determining red wine color, taste, flavor, and mouthfeel sensory attributes. Additionally, they contribute to wine aging and provide wine stability. This study evaluated the use of an attenuated total reflection (ATR) mid-infrared (MIR) spectroscopy to measure phenolic compounds in Shiraz wine samples of different quality levels obtained from 24 Australian wine geographical indications. Partial least squares (PLS) regression using the second derivative of the whole MIR spectrum produced the coefficient of determination (R2) in calibration and standard error in cross-validation (SECV) for different attributes. In particular, SO2-resistant pigments had R2 = 0.58 (SECV=0.58 au), total anthocyanins had R2 = 0.61 (SECV=32 mg/L), wine color density had R2 = 0.51 (SECV=0.56 au), and total phenolics had R2 = 0.60 (SECV=5.7 au). These results demonstrated the potential use of ATR-MIR spectroscopy with PLS regression as a rapid method to measure important parameters related to red wine phenolic composition and wine quality.

中文翻译：

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使用衰减全反射中红外 (ATR-MIR) 光谱法预测设拉子葡萄酒的酚类成分

酚类化合物在决定红葡萄酒的颜色、味道、风味和口感感官属性方面起着关键作用。此外，它们有助于葡萄酒老化并提供葡萄酒稳定性。本研究评估了使用衰减全反射 (ATR) 中红外 (MIR) 光谱测量从 24 个澳大利亚葡萄酒地理标志获得的不同质量水平的设拉子葡萄酒样品中的酚类化合物。使用整个 MIR 光谱的二阶导数的偏最小二乘 (PLS) 回归产生了校准中的决定系数 (R2) 和不同属性的交叉验证中的标准误差 (SECV)。特别是，抗 SO2 颜料的 R2 = 0.58 (SECV=0.58 au)，总花青素 R2 = 0.61 (SECV=32 mg/L)，酒色密度 R2 = 0.51 (SECV=0.56 au)，总酚类物质R2 = 0。60 (SECV=5.7 au)。这些结果证明了 ATR-MIR 光谱与 PLS 回归的潜在用途，作为测量与红葡萄酒酚类成分和葡萄酒质量相关的重要参数的快速方法。