Table 2 Manufacturing process of tea (Yamanishi 1992; Omori et al. 2017)

Raw leaves

70–80

(1) Withering

55–60

Natural withering 15–18 h

Artificial withering 12–15 h

25–28 °C

Activation of hydrolytic enzyme (β-glycosidase, β-primeverosidase), increase in precursor (alcoholic aroma component)

(2) Rolling

60–120 min

Formation of red pigment (theaflavin), increase in aroma component

(3) Fermenting

25 °C, 120–50 min

30 °C, 60–90 min

25–30 °C (Humidity over 90%)

Enzyme activation such as polyphenol oxidase, increase in various aroma components, formation of red pigment (theaflavin, thearubigin)

(4) Drying

3–4

15 min (Firing)

60 min (Drying)

80–90 °C (Firing)

70 °C (Drying)

Generating aroma components (aldehydes, ketones, yonon, lactone, etc.)

Tea (crushed tea)

3–4