Changes in theanine and caffeine contents of black tea with different rolling methods and processing stages
Küçük Resim Yok
Tarih
2013
Yazarlar
Sari F.
Velioglu Y.S.
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Theanine is a specific amino acid in tea, which has positive effects on health. Theanine contents of different grade Turkish teas, variations in the theanine content during tea processing, and the effects of different rolling processes on theanine content were determined. Theanine content of Turkish tea varying between 0.32 and 0.43 % has been reported for the first time by this study. Theanine content decreased in all processing steps from 10.0-3.42 to 7.73-3.97 mg g-1 dw in Orthodox and Cay-Kur methods, respectively. In both methods, the highest theanine loss (almost 50 %) was observed in the withering step, which was followed by drying step. Caffeine content of Turkish tea was determined varying between 1.8 and 2.2 %. While the caffeine content increased in the withering step, it decreased in other steps. The correlation between theanine and caffeine contents was evaluated. A high correlation (R 2 = 0.87) between the caffeine and theanine contents was found in teas classified by Cay-Kur method, and caffeine/theanine ratio was found to be around 5.3 in general. © 2013 Springer-Verlag Berlin Heidelberg.
Açıklama
Anahtar Kelimeler
Caffeine, Processing, Rolling method, Tea, Theanine
Kaynak
European Food Research and Technology
WoS Q Değeri
Scopus Q Değeri
Q2
Cilt
237
Sayı
2
