Research progress on identification methods of growth years of traditional Chinese medicinal materials

The growth years of traditional Chinese medicinal materials are closely related to their quality, which directly affects the efficacy and safety of clinical medication. Therefore, it is particularly important to establish an identification method for the growth years of traditional Chinese medicinal materials. In this review, the identification methods for the growth years of traditional Chinese medicinal materials were summarized systematically, and were divided into four types according to the identification principles and methods: traditional identification, molecular identification, physical/chemical identification, and integrated identification. Relying on rich experience, objective molecular markers, various physical/chemical methods and integrated identification techniques(including infrared spectroscopy, nuclear magnetic resonance spectroscopy, high performance liquid chromatography, gas chromatography, mass spectrometry, bionic identification technology and their tandem technologies, etc.), the differences of characters or chemical fingerprints were compared in depth. The growth years of traditional Chinese medicinal materials were quickly identified or predicted by the appearance and characters, the whole fingerprint information or the content of specific chemical markers, and their content ratios. Through the case analysis of mature varieties, we intend to promote the establishment of a perfect technology system for the identification of the growth years of traditional Chinese medicinal materials, and to provide a reference for other perennial herbal materials, finally resulting in the accurate and precise quality control of traditional Chinese medicinal materials.