TY  - SER
AU  - Huang,Luying
AU  - Anal,Anil Kumar
AU  - Athapol Noomhorm,
AU  - Muanmai Apintanapong, 
ED  - China Scholarship Council (CSC), 
TI  - Antimicrobial and antioxidant activities of extracts from the blacks in Thanh Hoa Province, Vietnam
T2  - Thesis
PY  - 2013///
CY  - Pathum Thani, Thailand
PB  - Asian Institute of Technology
KW  - Tea
KW  - Vietnam
KW  - Thanh Hoa
KW  - Antioxidants
N1  - A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development; Thesis (M. Sc.) - Asian Institute of Technology, 2013
N2  - The  aim  of  this  study  was  to  evaluate  the  antioxidant  and  antimicrobial  activities  of extracts  from  underutilized  black  tea  from  Vietnam. Response  surface  methodology  was applied  to  obtain  a  higher  total  phenolic  content  (TPC)  in  crude  tea  extract  by  using ultrasonic  assisted  extraction. The  results  of the  response TPCand  independent  factorswere  found  to  fit  the  second-order  polynomial  equations  that  obtained  by  applying  in  a multiple regression analysis, and relationship between all the independent factors: different concentrations  of  ethanol  and  temperature  and  time  were studied. It  found  that all  the independent  factors  were  significant  terms  for  extraction,  and  ethanol  concentrations  and temperature were the most significant terms to obtain a high TPC. Antimicrobial activities of  water  and  ethanol  extracts  were  studies.  It  found  that  both  water  and  ethanol  extracts had significant effect against the growth of Staphylococcusaureus.Different  extraction  methods  hadsignificant  effect  on  antioxidant  capacities  and  quality attributes of tea drinks. Tea extracted from lower temperature (60 °C) with water bath has a higher  sensory  score  and  overall  acceptability,  however  with  a lower  antioxidant  capacity compared tothe tea extracted from higher temperature (80 °C) with water bath. Ultrasonic assisted extraction combined with lower temperature (60 °C)can improve the antioxidant capacity of the tea drinks
UR  - http://203.159.5.9/ait-thesis/detail.php?q=B02827
ER  -