The low-cost, ultra-compact and handheld microNIR spectrometer over the spectral range of 1150–2150 nm was explored to detect the adulteration of wheat flour in this study. Eight varieties of cassava flour were used as adulterants and were adulterated in wheat flour at five adulteration levels of 5, 10, 20, 30 and 40%. Both principal component analysis-linear discriminant analysis (PCA-LDA) and partial least squares discriminant analysis (PLS-DA) methods were employed to establish 2-class, 3-class and 6-class discriminant models, using different types of preprocessed absorbance spectra. The overall prediction accuracies of the 2-class discriminant models all achieved over 95.00% in separating the pure and adulterated wheat flour, with the best overall accuracy of 97.53%, regardless of the adulterated cassava flour variety. The best overall prediction accuracy of 93.83% was obtained in discriminating the flour samples into the three classes of 0% (pure wheat), 5% + 10% and 20% + 30% + 40%, regardless of the adulterated cassava flour variety. However, the highest overall accuracy of the 6-class model attained only 75.31% in classifying the wheat samples into the six groups of 0% (pure wheat), 5, 10, 20, 30 and 40%, regardless of the adulterated cassava flour variety. Overall, the obtained results demonstrated the usefulness of the employed low-cost spectrometer in detecting the wheat flour adulteration in a rapid and non-destructive manner.

在本研究中，探索了一种低成本，超紧凑的手持式microNIR光谱仪，其光谱范围为1150–2150 nm，以检测小麦粉的掺假。使用八种木薯粉作为掺杂剂，并以5％，10％，20％，30％和40％的五个掺杂水平将其掺入小麦粉中。采用主成分分析-线性判别分析（PCA-LDA）和偏最小二乘判别分析（PLS-DA）方法，使用不同类型的预处理吸收光谱来建立2类，3类和6类判别模型。不论掺假木薯粉品种如何，两级判别模型的总体预测准确性在分离纯和掺假小麦粉中均达到95.00％以上，最佳总体准确度为97.53％。在将面粉样品区分为0％（纯小麦），5％+ 10％和20％+ 30％+ 40％的三个类别中，无论掺假的木薯粉品种如何，获得的最佳总体预测精度为93.83％。但是，将小麦样品分为0％（纯小麦），5％，10％，20％，30％和40％的六类小麦样品，无论掺入木薯粉如何，六级模型的最高总体准确性仅达到75.31％。品种。总的来说，所获得的结果证明了所采用的低成本光谱仪在以快速且无损的方式检测小麦粉掺假中的有用性。在将小麦样品分为0％（纯小麦），5％，10％，20％，30％和40％的六类小麦样品中，无论掺假的木薯粉品种如何，六级模型的最高总体准确性仅达到75.31％。总的来说，所获得的结果证明了所采用的低成本光谱仪在以快速且无损的方式检测小麦粉掺假中的有用性。在将小麦样品分为0％（纯小麦），5％，10％，20％，30％和40％的六类小麦样品中，无论掺假的木薯粉品种如何，六级模型的最高总体准确性仅达到75.31％。总的来说，所获得的结果证明了所采用的低成本光谱仪在以快速且无损的方式检测小麦粉掺假中的有用性。