Table 4.

Theanine extraction from tea leaves

Source of Theanine	Extraction parameters	Reference
Theanine by hot water extraction from Turkish tea	tea particle size 150–300 mm; extraction time 25 min and extraction temperature 80 °C	Sari and Velioglu 2011
L-theanine in Hawaii tea leaves	Decrease in L-theanine content with increasing leaf age, moving from the bud to first and second leaves	Song et al. 2012
water extraction of L-theanine,a non-protein amino acid	80 °C, 30 min, water:tea ratio of 20:1 mL/g and a tea particle size of 0.5–1 mm	Vuong et al. 2011a, 2011b