Quantification of food bioactives by NIR spectroscopy: Current insights, long-lasting challenges, and future trends

Conventional wet-chemistry methods for quantitative analysis of food bioactives are time-consuming, costly, and generate hazardous waste. Near-infrared (NIR) spectroscopy combined with chemometrics is a rapidly advancing way of quantifying food bioactives. This review presents the key principles and workflow for NIR model development. Sample representativeness, chemometrics methods, proper sample preparations, concentration of the analytes, optical features of the instruments, data distribution and postharvest process are key considerations for enhanced model performance. Additionally, this review critically discusses potential issues that have not been recognized in previous studies. Difficulties in obtaining comprehensive data set, comparison of different chemometric algorithms, data interpretation and method transfer are major challenges for NIR studies. Findable, Accessible, Interoperable and Reusable (FAIR) data management is proposed for future advancements of NIR methods. Theoretical calculation will shed light on result interpretation and calibration transfer. Wider applications of miniaturized NIR systems will benefit the quality control of entire value chain from farm to fork.