In order to investigate the effect of different combined drying methods on the qualities of peach crisps, vacuum freeze-drying(FD) was used as the basic and control method to produce peach crisps. FD was combined with other three methods including air drying(AD), microwave drying(MD) and air puffing drying(APD). The comparative drying experiments and quality analysis showed that comprehensive color index ΔE of peach crisps in FD-MD was significantly higher than other three groups, which resulted in the most color changes (p<0.05). In the microstructure of peach crisps, FD group formed a full porous network skeleton with high porosity, while FD-MD group resulted in serious collapsed dense structure in the tissue. FD-AD group and FD-APD group formed similar microstructures in the tissue which were between those of FD group and FD-MD group. The order of diameter shrinkage rate in peach crisps in four groups in decreasing sequence was FD-MD, FD-AD, FD-APD and FD, with significant difference. The moisture absorption rate of peach crisps in FD-MD group was significantly lower than those in other three groups, and FD group was the highest. The hardness and brittleness of peach crisps in FD-MD group were far higher than those in other three groups, with FD group was the lowest. The microstructure can better showed the differences in the qualities of peach crisps. In terms of the comprehensive qualities of the 4 groups of peach crisps, the FD-MD group was the worst, FD group was the best, and the other two groups were in the middle .
WANG Hai-ou, et al
. Effect of different combined freeze-drying methods on the qualities of peach crisp[J]. Food and Fermentation Industries, 2018
, 44(7)
: 173
-178
.
DOI: 10.13995/j.cnki.11-1802/ts.015929