Abstract:
Tea is one of the most popular beverages consumed worldwide. However,
during the production process, made tea can get contaminated with
microorganisms. This study was conducted to measure the microbial
contamination in made tea samples and the respective tea brew samples
brewed using a set of selected time temperature combinations. Contaminated
black tea samples were used for the analysis. Samples were analyzed for its
microbial load before brewing and after brewing at 700C, 850C,1000C for
3,5,6 minutes. The Total Plate Count (TPC), Yeast and Mould Count and
Total Coliform Count was done following (ISO 4833 -1:2013), (ISO 21527-
2:2008) and (ISO 4831:2006) methods. The study found that the TPC, Yeast
and Mould Count and Total coliform counts were 7.9×105 ± 1.2×105 CFU g1
, 5.1×103 ± 1.5×103 CFU g-1
, and >1100 MPN-g in contaminated made tea
samples before brewing. All brewing conditions reduced TPC in tea by more
than 99.8%, with the exception of 3 minutes at 70°C, where a reduction of
97.1 % was recorded. Similar behavior was observed in Yeast and Mould
count as more than 98.0% reduction was occurred by all brewing conditions.
The reduction of microbial load by brewing was significant at 95%
confidence level (P<0.05). Total Coliform was reduced to <0.3 MPN-g in all
brewed samples regardless of the time and temperature. Furthermore, there
was no considerable difference in reduction of microbial load between times
of brewing or temperatures. The study reveals that microbial load in made
tea is reduced to a considerable level in brewing.
