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A long term study
on the evaluation of shelf life of teas stored under
normal conditions had been carried out. No decline
in the quality parameters was noticed for a period
of nine months after which there had been a mild
but progressive decline in the level of quality
constituents. Experiments on the effect of temperature
on withering and fermentation have been carried
out at our miniature CTC unit . Highest percentage
of TF was observed when leaves were withered at
25o C and as the temperature increased,
there had been a steady decline in the quality.
The optimum temperature for fermentation was found
to be between 25 and 30o C. Time for
Optimum fermentation got reduced with the increase
in temperature but the quality of the end product
deteriorated.
 A
Comparative study on the keeping quality of teas
stored in three different packing materials viz.,
Aluminum foil, LDPE and jute bags (lined with polythene)
was conducted. Moisture absorption was higher in
the teas stored in jute bags followed by LDPE bags.
Aluminium foil pouches resisted moisture absorption
and kept the tea well. Additionally, the teas were
stored at warehouses at Cochin as well as at Coimbatore.
The tea stored at Cochin absorbed more moisture
than those stored at Coimbatore. Broken Orange Pekoe
( BOP ) and Pekoe dust ( PD ) were used in the study
and both had the similar trend.
 Biochemical
studies during fermentation was carried out using
the clone UPASI-3. Observations on the total polyphenols
and theaflavins during fermentation revealed a progressive
decline in the polyphenol level and an increase
in the theaflavin till the optimum fermentation
time of forty five minutes. The results on made
tea analysis for the other quality constituents
and various TF fractions also showed maximum quality
with regard to the liquor characteristics at forty
five minutes, which is the optimum fermentation
time for UPASI-3.
 In
connection with the studies on pacha taint in CTC
teas, a methodology for the assay of lipase has
been standardized. There was a progressive decline
in lipase activity as the maturity of the shoot
increased. Miniature level trials on the alleviation
of pacha taint with the help of lipid degrading
enzymes such as lipase, lipoxygenase, alcohol dehydrogenase
and anti oxidants such as butylated hydroxy anisole(BHA)
and ascorbic acid have been carried out with encouraging
observations. A combination of lipase and lipoxygenase
was found useful in decreasing the content of lipids
and increasing the quality parameters. A study was
undertaken to evaluate the impact of different methods
of withering on lipid degradation. Maximum lipid
degradation was observed in ultraviolet radiation
and warm air withering.
Evaluation of flavors profile of Nilgiris tea had
been carried out with orthodox tea sample of BOP
grade procured from different agro climatic zones
of the Nilgiris. Highest flavour index ( FI ) was
noted in the month of January followed by October.
The cool, dry weather could have the contributing
factor the improvement in flavour.
A comparative study on the biochemical and quality
parameters of NRC and RC teas showed that in addition
to the better liquoring merit, non-RC teas had almost
all the biochemical and quality constituents at
a higher level. The increase had been significant.
 The
impact of foliar application of certain nutrients
such as SOP, potassium nitrate and calcium nitrate
on the quality of tea had been studied. Application
of SOP at 2% level significantly increased the levels
of polyphenols, catechins, theaflavins, thearubigins,
briskness and color indices against control. Improvement
was also noticed by tasters which substantiated
the observations on biochemical parameters. Application
of potassium nitrate significantly increased the
biochemical precursors such as polyphenols and catechins.
Foliar application of Calcium nitrate had no significant
effect on tea quality.
The effect of oxygen addition during fermentation
on CTC black tea quality was evaluated. The made
tea produced from the oxygen treated samples showed
an overall improvement in the quality parameters
which was substantiated by professional tasters.
A chilled tea beverage with natural tea flavour
has been attempted with encouraging results. Further
work on stabilization of the product with preservatives
and stabilizers is in progress. Experiments on freeze
withering, flavor incorporation in made tea are
under way. Extraction of polyphenols from black
tea and tea waste is also being standardized.
 To
study the influence of the quality of raw material
on electrical power consumption and quality of CTC
black tea, an experiment was conducted. Crop shoots
of the clone UPASI –9 were segregated into
three portions comprising 100% fine leaves, 75%
fine leaves and 50% fine leaves. Two leaves and
a bud , three leaves and a bud , soft banjies and
single leaves were taken as fine leaf. Leaves above
third leaf, cut and black leaves were considered
as coarse leaves. Electrical power consumption was
highest for the treatment involving 50% fine leaves
and it decreased by 14% for 75% fine leaves and
24% for 100% fine leaves.The presence of coarse
leaves besides deteriorating the quality increased
the electrical power consumption during manufacture
and increased the cost of production .
Refinement of existing analytical techniques is
also taken as a priority area of research. Methods
have been developed for the assessment of ascorbic
acid in crop shoots of tea reducing power and antioxidant
activity in the black teas.
Besides the above mentioned works, division is also
providing regular analytical service to the industry
by way of analyzing made tea samples for PFA Act
requirements. The laboratory has been accredited
by NABL under ISO/IEC 17025.
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