V. CONCLUSION AND RECOMMENDATIONS
5.1 CONCLUSION
Both factors, the pretreatment and the drying temperature, had effect on quality of dried bamboo shoots. They had a tendency to give opposite effect on some parameters. Drying time
decreased with increase in drying temperature. The unpretreated bamboo shoots needed longer drying time than the pretreated one. Water activity of dried bamboo shoots was not significantly
affected p0.05 by the concentration of sodium metabisulfite used in blanching solution and the drying time as well as dimensional changes shrinkage and firmness of rehydrated bamboo
shoots. On the contrary, color of dried and rehydrated bamboo shoots, firmness of dried bamboo shoots, rehydration ratio, and total residual sulfites were significantly p0.05 affected by both
factors. The L and b value increased with increase in concentration of sodium metabisulfite and
with decrease in drying temperature, whereas the a value decreased. The highest b value of dried bamboo shoots was found in the sample blanched in 1.5 sodium metabisulfite solution and then
dried at 50 ⁰C, yet it was not significantly different p0.05 with the sample that blanched in 1.0
sodium metabisulfite solution and then dried at 60 ⁰C. After rehydration, there was no
significantly difference p0.05 among the rehydrated samples on the b value. The same tendency was found on rehydration ratio parameter. The sample blanched in 1.5 sodium
metabisulfite solution and then dried at 50 ⁰C was not significantly different p0.05 with the
sample blanched in 1.0 sodium metabisulfite solution and then dried at 60 ⁰C, yet they had
higher rehydration ratio p0.01 than the sample blanched in the other concentrations. In contrast to L and b value and rehydration ratio, firmness of dried bamboo shoots and total residual
sulfites increased with increase in both concentration of sodium metabisulfite and drying temperature. The highest firmness was found in the sample dried at 70
⁰C, followed by the sample dried at 60
⁰C and 50 ⁰C, yet, it was observed that there were some data which had overlapped standard deviation due to wrong in sampling of texture analysis. The total residual sulfites ranged
from 1250 to 3378 ppm SO
2
while the highest residual sulfites was found in all samples blanched in 1.5 sodium metabisulfite solution.
Sample blanched in 1.5 sodium metabisulfite solution and then dried 70 ⁰C had the
highest total weighted score. The sample was considered to be the best sample, yet it should be noted that the dried product may not contain more than 2500 ppm SO
2
and blanching the sample in 1.5 sodium metabisulfite solution produced the dried bamboo shoots contained more than 2500
ppm SO
2
. Considering the above results, it was suggested that the sample blanched in 1.0 sodium
metabisulfite solution and then dried at 60 ⁰C was the best sample to be sensory tested.
Results of hedonic rating test confirmed that the rehydrated-dried bamboo shoots produced at the lab were more preferable than the rehydrated-dried bamboo shoots commercially sold in
Mae Sai market. Hence, based on the physical, chemical, and sensory analysis, it is suggested that blanching sample in 1.0 Na
2
S
2
O
5
solution and drying sample at 60 ⁰C is a better condition to
produce dried bamboo shoots with a desired quality which is applicable in Doi Tung.
37
5.2 RECOMMENDATIONS
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