Progress of near infrared spectroscopy in tea research

Tea is a widely favored health beverage, with its quality influenced by a range of factors including cultivar, geographic origin, and processing methods. With the growing consumer demand for high-quality tea, fresh leaf quality assessment has traditionally relied on manual evaluation or physicochemical analyses. However, these approaches are often time-consuming and destructive. Therefore, the development of a safe, rapid, and reliable method for tea quality assessment is essential for the advancement of the tea industry. Near-infrared spectroscopy (NIRS), known for its non-destructive nature and rapid response, has been extensively applied in tea quality control. This review summarizes the applications of NIRS in tea classification, quality evaluation, chemical composition analysis, and monitoring of processing procedures, highlighting recent advances in the field. Furthermore, it emphasizes the emerging role of portable NIRS devices in tea quality assessment and discusses current challenges and future perspectives for NIRS technology in this domain.