TY - JOUR
T1 - Unique bioactive polyphenolic profile of guava (Psidium guajava) budding leaf tea is related to plant biochemistry of budding leaves in early dawn
AU - Chang, Chi Huang
AU - Hsieh, Chiu Lan
AU - Wang, Hui Er
AU - Peng, Chiung Chi
AU - Chyau, Charng Cherng
AU - Peng, Robert Y.
PY - 2013/3/15
Y1 - 2013/3/15
N2 - BACKGROUND: Guava leaf tea (GLT), exhibiting a diversity of medicinal bioactivities, has become a popularly consumed daily beverage. To improve the product quality, a new process was recommended to the Ser-Tou Farmers' Association (SFA), who began field production in 2005. The new process comprised simplified steps: one bud-two leaves were plucked at 3:00-6:00 am, in the early dawn period, followed by withering at ambient temperature (25-28 °C), rolling at 50 °C for 50-70 min, with or without fermentation, then drying at 45-50 °C for 70-90 min, and finally sorted. RESULTS: The product manufactured by this new process (named herein GLTSF) exhibited higher contents (in mg g-1, based on dry ethyl acetate fraction/methanolic extract) of polyphenolics (417.9 ± 12.3) and flavonoids (452.5 ± 32.3) containing a compositional profile much simpler than previously found: total quercetins (190.3 ± 9.1), total myricetin (3.3 ± 0.9), total catechins (36.4 ± 5.3), gallic acid (8.8 ± 0.6), ellagic acid (39.1 ± 6.4) and tannins (2.5 ± 9.1). CONCLUSION: We have successfully developed a new process for manufacturing GLTSF with a unique polyphenolic profile. Such characteristic compositional distribution can be ascribed to the right harvesting hour in the early dawn and appropriate treatment process at low temperature, avoiding direct sunlight.
AB - BACKGROUND: Guava leaf tea (GLT), exhibiting a diversity of medicinal bioactivities, has become a popularly consumed daily beverage. To improve the product quality, a new process was recommended to the Ser-Tou Farmers' Association (SFA), who began field production in 2005. The new process comprised simplified steps: one bud-two leaves were plucked at 3:00-6:00 am, in the early dawn period, followed by withering at ambient temperature (25-28 °C), rolling at 50 °C for 50-70 min, with or without fermentation, then drying at 45-50 °C for 70-90 min, and finally sorted. RESULTS: The product manufactured by this new process (named herein GLTSF) exhibited higher contents (in mg g-1, based on dry ethyl acetate fraction/methanolic extract) of polyphenolics (417.9 ± 12.3) and flavonoids (452.5 ± 32.3) containing a compositional profile much simpler than previously found: total quercetins (190.3 ± 9.1), total myricetin (3.3 ± 0.9), total catechins (36.4 ± 5.3), gallic acid (8.8 ± 0.6), ellagic acid (39.1 ± 6.4) and tannins (2.5 ± 9.1). CONCLUSION: We have successfully developed a new process for manufacturing GLTSF with a unique polyphenolic profile. Such characteristic compositional distribution can be ascribed to the right harvesting hour in the early dawn and appropriate treatment process at low temperature, avoiding direct sunlight.
KW - Catechin
KW - Ellagic acid
KW - Gallic acid
KW - Guava tea
KW - Polyphenolics and flavonoids
KW - Quercetin
UR - http://www.scopus.com/inward/record.url?scp=84874022802&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84874022802&partnerID=8YFLogxK
U2 - 10.1002/jsfa.5832
DO - 10.1002/jsfa.5832
M3 - Article
C2 - 22926797
AN - SCOPUS:84874022802
SN - 0022-5142
VL - 93
SP - 944
EP - 954
JO - Journal of the Science of Food and Agriculture
JF - Journal of the Science of Food and Agriculture
IS - 4
ER -