This work aimed at studying the effects of pretreatment, namely, hot water blanching, and hot air-drying
(60–120 C) on the evolutions of vitamin C, phenolic compounds, nomilin and limonin, which are potential
bioactive compounds in lime residues during drying. Blanching was found to decrease both the antioxidant
contents and activities of the residues due to thermal degradation and loss with the blanched
water. During drying, nomilin and limonin contents first increased, probably due to the remaining
enzyme activity after blanching. After this period, the amounts of both nomilin and limonin dropped rapidly,
due to thermal degradation. Product temperature was found to be a major factor controlling the
changes of limonoids and there was no direct correlation between the moisture change during drying
and limonoid contents. During degradation of vitamin C and phenolic compounds, the amounts of both
substances decreased as the product temperature increased and the moisture content decreased during
drying. The amount of phenolic compounds correlated well with the total antioxidant activity and phenolic
compounds were found to be a major contributor to antioxidant activity of the product.