Exploring the Quality and Application Potential of the Remaining Tea Stems after the Postharvest Tea Leaves: The Example of Lu’an Guapian Tea (Camellia sinensis L.)

Abstract

Lu’an Guapian tea is produced through the processing of only leaves, with the stems and buds discarded, but stems constitute a large proportion of the tea harvest. To test the usability of tea stems, we compared the physicochemical properties of tea leaves and stems from the same growth period as well as the taste of their infusions. The leaves contained higher concentrations of polyphenols and caffeine and had a stronger taste. The tea stems contained higher concentrations of free amino acids and soluble sugars and were richer in umami and sweet flavors. In addition, more tender tea stems had higher concentrations of polyphenols, caffeine, and free amino acids, and their infusions had more refreshing and sweeter tastes. Furthermore, crude fiber content increased as stem tenderness decreased. In summary, tea stems are rich in phytochemical components and flavor, and these properties increased with tenderness. This provides a theoretical basis for the high-value utilization of tea stems.

Keemun black tea stems and leaves: Comparison of chemical characterization and anti-inflammatory activities

“…The same study reported that stems significantly increased the umami taste of oolong tea. Similarly, Zhang et al [7] reported that Lu'an Guapian tea stems and leaves infusions showed distinct flavor profiles, the leaf infusions being more bitter and astringent and the stem infusions being sweeter and richer in umami. Furthermore, several reports also highlighted tea stems' antioxidant and antigenotoxic activities [8,9].…”

Effects of Different Expansion Temperatures on the Non-Volatile Qualities of Tea Stems

“…Tea (Camellia sinensis), originating in China, is one of the most popular beverages globally [1]. It is widely known for its distinctive flavor and recognized efficacy [2,3]. Moreover, its biological activities are thought to be mainly related to L-theanine, caffeine, flavan-3-ol, and polysaccharides [4][5][6].…”

“…Tea stems are a leaf stalk plucked from finished tea, constituting approximately 35% of the dry weight of tea leaves [2]. They primarily contain tea polyphenols, tea polysaccharides, amino acids, alkaloids, aromatic compounds, and other active ingredients.…”