Black tea is the most widely consumed tea globally, yet its traditional empirical production suffers from unstable quality and low efficiency, conflicting with modern industrial standards. Near infrared spectroscopy (NIRS), a rapid and nondestructive technological tool, has emerged as key enable for the digital transformation of black tea production by supporting data-driven processing decisions and real-time quality assessment. This review summarizes NIRS across all black tea processing stages and post-production control, identifies core technical bottlenecks hindering industrial scaling with targeted solutions, and outlines future directions focusing on data fusion and monitoring-control system integration. Literature analysis reveals NIRS is validated for most scenarios of black tea production but remains predominantly lab-based, in industrial application is promising with advanced devices and algorithms. This review bridges lab-industry gaps, laying a foundation for Industry 4.0-aligned data-driven precision production in the black tea industry.
Zhu et al. (Sat,) studied this question.