Abstract
Aim:
The aim of the present study was to evaluate the presence of bittering
factors limonin and naringin in kinnow fruits and to elucidate the process of
kinnow juice de-bittering.
Methodology: Limonin and naringin concentration was quantified
using reverse phase HPLC. Both the constituents were evaluated in various
compartments of fruits viz. seeds, albedo, flavedo, pomace and juice. The
extracted kinnow juice was assessed for bittering factors during various
months of harvesting, as well as during storage with variable pH (3, 4, 5)
and temperature (low and ambient). Further, various adsorbents were tried on
juice to adsorb limonin and naringin in order to elucidate the process of
kinnow juice de-bittering.?????
Results:
Limonin and naringin were found to be the highest in seed and albedo
portions. The level of limonin decreased with increasing pH and with low
temperature storage comparatively. XAD-7 and XAD-16 were found to be at par
as well as the most effective adsorbents in reducing bitterness compared to
rest of the adsorbents tested.
Interpretation: A process has been devised which
involves manual removal of peel and seeds followed by treatment of extracted
juice with centrifugation and activated carbon to reduce bittering
constituents below their threshold levels in the final juice. The process
does not require complex set-up of equipment and costly adsorbents.
Key
words:
Bitterness index, Harvesting time, Limonin, Naringin, Reverse phase HPLC
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