基于FTIR技术的酸牛奶营养成分快速检测方法研究

酸牛奶作为一种重要的发酵乳制品，伴随着发酵过程，其各种营养成分时刻发生着复杂的变化，因此，建立酸牛奶的快速高效检测技术可以实现对生产过程的实时监控，这也是食品安全监管要达到的重要目标。傅里叶变换红外光谱技术(FTIR)因其快速、高通量、无化学污染、可对掺假成分予以分辨等特点被广泛应用于食品安全领域。以FTIR技术为核心，利用氟化钙薄膜法，将酸牛奶FTIR光谱图与其营养成分(能量值，蛋白质、脂肪、碳水化合物和钠含量)对照，建立了基于最小二乘法(PLS)的定量化预测模型。结果表明，该模型样品校正集的能量值，蛋白质、脂肪、碳水化合物和钠含量的交叉检验R2值分别达到0.938 9，0.926 6，0.918 6，0.941 8和0.977 1;该模型用于预测，其样品验证集的交叉检验R2值分别为0.920 5，0.905 3，0.908 5，0.939 3和0.936 4。由此可见，该模型对酸牛奶各营养指标均具有较好的预测准确性，在时间上具备较好的稳定性。不同于传统的化学检测方法，本研究为实现对酸牛奶品质的快速检测提供了一种较为可行的方法。该方法作为乳制品质量监控技术的一项初步探索，具有较好的应用前景。

Quantitive Analysis of Contents in Yogurt and Application Research with FTIR Spectroscopy

Yogurt is a food produced by bacterial fermentation of milk.All kinds of nutrition components are changing dramatic-ally in the process of fermentation.Therefore,it is important to establish a fast and efficient measurement technology of yogurt nutrition,which is also an important goal for food safety supervision in terms of monitoring the yogurt production process in real time.Fourier transform infrared spectroscopy (FTIR)has been widely used in the field of food safety,for it has high efficiency, high throughput,no chemical pollution,thus it can be used in the inspection of food adulteration.Our study has established a quantitative model to predict the nutrition components in yogurt,such as energy value,protein,fat,carbohydrates and sodium content.Based on the least squares (PLS)method,the model used CaF2 film FTIR technology.The results show that the new model can be used in quality control of yogurt production process:The R2 values of the model were 0.938 9,0.926 6,0.918 6, 0.941 8 and 0.977 1,comparing energetic value,protein,fat,carbohydrate and sodium contents with the original spectrum of calibration samples by cross validation.And the predictive R2 are 0.920 5,0.905 3,0.908 5,0.939 3 and 0.936 4 respectively. Thus,the model has good prediction accuracy and reliability,which provides a feasible method for the rapid measurement of yo-gurt quality.As a preliminary exploration of the quality control technology of dairy products,this method has a good prospect of application.