Rapid determination of water content in an inter-species model using near-infrared spectroscopy

Spices play an important role in human nutrition due to their many aromatic, coloring, and flavoring properties. Their commercial value depends heavily on several factors such as their sanitary quality, authenticity, and origin, therefore it is necessary to incorporate them into a quality control process. Among these criteria, water content is an important parameter because poorly controlled moisture can lead to an alteration of organoleptic properties or promote microbial growth within the spices. In this context, this study proposes a rapid, non-destructive, and reliable analytical method based on near-infrared spectroscopy coupled with chemometric analyses to predict the water content of a wide range of spices. 127 samples belonging to 35 types of spices were used with reference values obtained by azeotropic distillation. The model has high predictive performance (R² = 0.93; RMSEC (Root Mean Square Error of Calibration) = 0.67), confirming the robustness of the approach. These results demonstrate the value of a standardized approach to calibration and validate the coupling used as a promising tool for spice quality control.