White Leaf Tea Made from Different Cultivars by Strong Shading Treatment

Abstract

The tea (Camellia sinensis cv. 'Yabukita') leaves grown under the strong shading treatment are tinged with white as well as increase the content of amino acids. We investigated the effects on the tea leaves by this treatment, using nine distantly-related cultivars. As a result, all cultivars' leaves turned white color dramatically and increased the content of amino acids. It was considered that the change of tea leaf color under this treatment has nothing to do with genotype, since amino acids in white leaves grown under this treatment differ in composition from those in normal white leaf tea cultivars. Accordingly, this technique is expected to be applicable for any tea cultivars.

Effect of shading intensity on morphological and color traits and on chemical components of new tea (Camellia sinensis L.) shoots under direct covering cultivation

“…These results were similar to those reported by Chutani and Takewaka . By contrast, Inaba et al . reported that SPAD values of new tea leaves decrease under extremely dark conditions, although those of white leaf tea cultivars or lines increased.…”

“…These results were similar to those reported by Chutani and Takewaka. 5 By contrast, Inaba et al 34 reported that SPAD values of new tea leaves decrease under extremely dark conditions, although those of white leaf tea cultivars or lines increased. Irradiance effects on SPAD values and chlorophyll contents can vary depending on radiation intensity and cultivar.…”

Antidepressant Effect of Shaded White Leaf Tea Containing High Levels of Caffeine and Amino Acids

“…On the other hand, strong shading causes growth suppression and metabolism changes in tea leaves. Therefore, shading the tea leaves increases the amino acid content [ 3 ] but causes a large change in the ratio of each amino acid. The proportion of Thea declined, while the proportions of Arg, Gln, Asn, and Ser increased significantly ( Figure 1 ).…”

“…Tea ( Camellia sinensis (L.) Kuntze ) leaves were collected in Shizuoka, Japan in May. About two weeks before harvesting, the leaves were protected from direct sunlight with a shading net [ 3 ]. Then, the tea leaves were made into green tea through the usual process.…”

“…However, these cultivars have disadvantages, such as low yield and difficulties with propagation. Therefore, a technique has been developed in which the green tea leaves of a general cultivar, such as “Yabukita,” are turned yellowish-white by completely protecting them from light [ 3 ]. If the young leaves are protected from sunlight with a shading net for about two weeks, the decomposition of theanine is suppressed, resulting in green tea with an increased amount of amino acids compared to normal green tea [ 4 ].…”