EFFECT OF SOLVENT TYPE ON EXTRACTION
OF ANTIOXIDANTS
Solvents such as methanol, ethanol, acetone, propanol,
ethyl acetate and dimethylformamide often used in the
extraction of antioxidant compounds from fresh fruits/
vegetables at different concentration (Alothman et al.
2009). Solubility of antioxidant compounds in solvent
was proven to have strong influence on the recovery of
those compounds during the extraction processes. In other
words, polarity of solvents indirectly played a vital role
in extraction process since it would increase the solubility
of antioxidant compounds (Alothman et al. 2009). It was
impossible to develop a standard solvent that was suitable
for the all kinds of antioxidant compounds extraction from
plants. Thus, screening process was important to justify
the best solvent in antioxidant compounds extraction so
that the maximum antioxidant activity for a certain sample
could be identifed.
Results indicated that the recovery of antioxidant
compounds depends very much on the type and polarity
of solvent used. The best solvent for DPPH assays was 70%
ethanol for all banana cultivars studied (Table 1). However,
the 70% acetone solvent seemed to have the best extraction
power among all the solvent systems used for FRAP and
TPC assays (Table 2 & 3). This observation was similar
to the result reported by Alothman et al. (2009) where
these authors found out that acetone 70% was the best
solvent in antioxidant compounds extraction for TPC assays
but second effective solvent for FRAP and DPPH assays.
Saravanan and Aradhya (2011) concluded that acetone is
the most powerful solvent in extracting the antioxidant
compounds from banana tissues while Wang et al. (1996)
used pure acetone (100% concentration) in extracting
antioxidant compounds from several kinds of fruit tissues
including banana for their studies. In contrast, Yan et al.
(2006) used ethanol 50% in their extraction of antioxidant
compounds from banana tissues. However, no screening
of solvents had been carried out by two latter groups of
authors thus no comparison of the effciency of acetone
and ethanol as extraction solvents could be done.