value
(Wang et al., 2010), which implies higher microwave energy
conversion efficiency (Wang and Chen, 2003) and hence results
in higher drying rate. Moreover, it could be seen that there
was no significant difference in drying time even between 20%
and 50% lychee proportion paste (p > 0.05). It means that the
effect of sugar on drying rate can be neglected when the water
content is below 30% (w.b.). The ε values of paste mixture of
different ratio are shown in Table 1. It shows that water content
dominantly influenced materials ε values (Wang et al.,
2011). The effect of water content was greater than that of
sugar content at last drying stages.
Sensory evaluation results shown in Table 1 indicate the
scores of dried chips with 5:5 and 6:4 both exceeded 8,
which means the two chips have significant tacky mouth feel.
Although the higher lychee content could bring the stronger
lychee taste, tacky mouth feel which would decrease people’s
liking. So, the desirable ratio of purple sweet potato to lychee
was found to be 7:3 (W:W)