Cocoa and Chocolate Processing: Quality Changes, Monitoring Approaches, and Opportunities for Rapid and Non-Destructive Analysis Using Near Infrared Spectroscopy and Hyperspectral Imaging

Cocoa and chocolate quality are strongly influenced by the different processing stages involved throughout production, since physicochemical and sensory changes occurring during these steps directly affect the characteristics of the final product. Conventional quality control methods commonly used to monitor these changes are often labor-intensive, destructive, time-consuming, and dependent on chemical reagents, limiting their applicability for rapid industrial monitoring. In this context, rapid and non-destructive analytical technologies have emerged as promising alternatives for quality assessment and process monitoring in the cocoa and chocolate industry. Techniques such as near-infrared (NIR) spectroscopy and hyperspectral imaging (HSI) enable fast, non-invasive, and environmentally friendly analysis of both chemical composition and physical attributes of cocoa and chocolate products. This review critically examines the main quality changes occurring throughout cocoa and chocolate processing and relates them to conventional and rapid analytical strategies, with particular emphasis on NIR spectroscopy and HSI coupled with chemometrics. The analytical capabilities of these technologies are discussed in relation to sample characteristics, spectral information, spatial heterogeneity, model performance, validation requirements, and potential industrial implementation. Particular attention is given to the complementary roles of NIR and HSI, considering the balance between analytical performance, acquisition speed, instrumental complexity, and the added value of spatial information.