Quantitative Assessment of Wheat Quality Using Near Infrared Spectroscopy: A Comprehensive Review

Authors: DU, ZHENJIAO - Kansas State University; TIAN, WENFRI - Kansas State University; Tilley, Michael - Mike; WANG, DONGHAI - Kansas State University; ZHANG, GUORONG - Kansas State University; LI, YONGHUI - Kansas State University

Submitted to: Comprehensive Reviews in Food Science and Food Safety
Publication Type: Literature Review
Publication Acceptance Date: 3/16/2022
Publication Date: 5/23/2022
Citation: Du, Z., Tian, W., Tilley, M., Wang, D., Zhang, G., Li, Y. 2022. Quantitative Assessment of Wheat Quality Using Near Infrared Spectroscopy: A Comprehensive Review. Comprehensive Reviews in Food Science and Food Safety. 21:2956-3009. https://doi.org/10.1111/1541-4337.12958.
DOI: https://doi.org/10.1111/1541-4337.12958

Interpretive Summary: Wheat (Triticum aestivum L.) is one of the most cultivated crops worldwide. Approximately 65% of wheat is used for human consumption, though it is also widely utilized in other fields such as feed, energy, and non-food industries. Depending on different end uses, quality classification based on wheat compositions or functionalities has been developed in many countries. However, these classification methods are general and do not allow precise quantitative quality assessment. Breeders, millers, bakers, and other end-users demand precise quantitative assessments of wheat, because quality has a great impact on breeding, processing, and marketing, and precise quantitative assessment allows maximum utilization of kernel, flour, and dough. Quality indicators of wheat include analytical parameters (e.g., protein content, falling number), rheological parameters (e.g., mixing resistance, viscoelasticity), and end product quality parameters (e.g., bread loaf volume, texture). Conventional assessment methods that use chemistry experiments are laborious, time-consuming, expensive, and not environmentally friendly and require experienced technicians. Given the disadvantages of traditional assessment methods and the heavy use of wheat as well as wheat products, there is a great demand for rapid, low-cost, non-destructive, simple, and environmentally friendly assessment methods to evaluate the quality of wheat kernels, ground flours, dough, and end products. To meet this demand, researchers have studied and applied spectroscopic approaches such as nuclear magnetic resonance (NMR), fluorescence spectroscopy (FS), X-ray computed tomography (CT), hyperspectral imaging (HSI), ultraviolet spectroscopy, visible spectroscopy, mid infrared spectroscopy (MIRS). Compared to these methods, near infrared spectroscopy (NIRS) is the most popular one given its advantages in throughput, portability, versatility, simplicity, sample particularity, and cost. This review presents the principles, spectra acquisition, pretreatments, wavelength selection, outlier treatments, data set division, and model development in NIRS methods. Especially, the application of NIRS in quantitative assessments of compositional parameters, physical parameters, rheological parameters, and end-product quality was also reviewed. Furthermore, it discusses future development trends of the NIRS technology in the wheat quality assessment

Technical Abstract: Wheat is one of the most cultivated crops. A great need exists in wheat quality assessment for breeding, processing, and products production purposes. Near infrared spectroscopy (NIRS) is a rapid, low-cost, simple, and non-destructive assessment method. Many advanced studies associated with NIRS for wheat quality assessment have recently been published, either introducing new chemometrics or attempting new assessment parameters to improve model robustness and accuracy. This review provides a comprehensive overview of NIRS methodology including its principle, spectra pretreatments, spectral wavelength selection, outlier disposal, data set division, regression methods, and model evaluation. More importantly, the applications of NIRS in the determination of analytical parameters, rheological parameters, and end-product quality of wheat are summarized. NIRS showed great potential in the quantitative determination of analytical parameters, rheological parameters, and end-product quality for wheat products. There are still some challenges in model robustness and accuracy when determining rheological parameters and end-user quality. Future model development needs to incorporate larger databases, integrate different spectroscopic techniques, and introduce edge-cutting chemometric methods. In addition, calibration based on external factors should be considered to improve predicted results of the calibration model. The NIRS application in micronutrients needs to be extended. Last, the idea of combining standard product sensory attributes and spectra for model development deserves further study.