The oil content curves for microwave pretreated samples, both
in the coating and core (Fig. 2) layers show obvious reduction
compared with frying without pretreatment. Therewas a 26.22 and
33.51% reduction in final fat content of the coating as a result of
microwave pretreatment for 1 and 2 min, respectively, compared to
the control. The trend shown for the core is quite similar, with
a reduction of 10.95 and 16.66%, respectively. ANOVA shows that
the pretreatment time and frying time had high significant influence
(P < 0.05) on the oil content. DMRTalso indicates that there
were significant differences (P< 0.05) existing among different
pretreatments in the coating and core layers, with longer pretreatment
time giving less oil absorption. This may be attributed to
the reduction in moisture content of the nuggets and structural
change with a modified moisture distribution during microwave
pretreatment, which subsequently influenced fat uptake. Therewas
pre-gelatinization of the chicken nuggets during microwave treatment,
which might also be partly responsible for structural change
that influenced fat uptake. Gamble and Rice (1987) reported similar
results in their study on the effect of hot air and microwave predrying
on mass transfer kinetics of deep-fried potato crisps. There
was a sudden increase in fat content of the samples in the first 60 s
of frying and this tends to flatten out as frying progressed. The
formation of compact surface or crust as a result of quick moisture
loss and starch gelatinization may be responsible for this phenomenon
(Debnath et al., 2003; Song, Zhang, & Mujumdar, 2007).
Similar results were presented by Tran, Chen, and Southern (2007)
for pre-dried deep-fat fried potato crisp.