Correlation between leaf age, shade levels, and characteristic beneficial natural constituents of tea (Camellia sinensis) grown in Hawaii

► Unique investigation of leaf age and shade on six important compounds found in tea. ► Compounds analysed were l-theanine, caffeine, EGCG, EGC, EC, and ECG. ► First study of its type on Hawaiian-grown tea. ► Results show l-theanine and caffeine levels decrease with leaf age and catechin levels increase. ► Concentration of the catechin EGC increased up to 10-fold in moving from the bud to the second leaf.