Volatile and flavour compounds analysis reveal quality constituents of Qianlin tea (Camellia cuspidata) to diversify tea products

• Qianlin tea and green tea did not differ in polyphenol and water leachate contents. • Asparagine, arginine, and others accumulate significantly in Qianlin tea. • Qianlin tea has a unique aroma and a bright, clear soup color. • Qianlin tea has potential in the development of fruit-flavored green tea, white tea. • Qianlin tea can produce black tea with functional value. Increased attention has been attracted by unique beverage plants resources which specifically accumulate metabolites, such as anthocyanin, catechin and caffeine, because of special flavor quality or high efficacy activity. To reveal the key metabolites constituting the quality of Qianlin tea, a tradition drink processed from Camellia cuspidate, sensory quality, amino acids, flavonoids, and volatile metabolites were comprehensively investigated. The Qianlin white, black, and green teas exhibited rich and unique taste and aroma qualities with distinct colors of bright yellow-green, reddish-brown, and golden, respectively. Qianlin green tea had fresh and mellow flavor characteristics with an evident apple aroma. There were no significant differences in the water extract components between the three types of Qianlin teas and that of ordinary green tea (processed with Camellia sinensis ), although none of the Qianlin teas contained caffeine. All three Qianlin teas contained only trace amounts of catechins, and there was no difference in the total amount of tea polyphenols between the Qianlin teas and ordinary green tea. The total amount of amino acids in the Qianlin teas was significantly lower than that of ordinary green tea and the Qianlin teas did not contain theanine, whereas the contents of asparagine and arginine were significantly higher than those of ordinary green tea. Compared with Qianlin green tea, the contents of asparagine, arginine, γ-aminobutyric acid, and phosphatidylserine were higher in Qianlin white and black teas. β-Linalool (42.81 % to 67.76 %), Terpinen-4-ol and α-terpineol are the main aroma presenting substances in the aroma of Qianlin tea. The results provided a basis for us to understand the quality-related volatile and nonvolatile metabolites of Qianlin tea, further to diversify tea products.