earlier reported method [30]. A total of 100 μL of each solventextract was added to 10 mL of freshly prepared DNPH solution. The solutions were allowed to stand for 60 min at ambient temperature and after which were centrifuged at 700 rpmfor 10 min. Absorbance of the unreacted DNPH in the supernatant liquid was measured at wavelength, λmax. = 326 nm.The total aldehyde content was calculated according to Eq. 1:Total aldehyde content mmol ð Þ=g¼Reacted DNPH mmolð Þ=g198:14 0:0001 ð1Þ