Abstract Studies were carried out to evaluate the effect of blanching time, temperature and potato tuber bruises on the reducing sugar levels of potato tubers sold in market outlets within Abakaliki metropolis, Ebonyi State, using dinitrosalicyclic assay. The mean reducing sugar levels in the tuber samples with no bruise, light bruises and heavy bruises were 2.86±0.21, 3.22±0.18 and 4.69±0.52mg/g respectively. The presence of bruises in the tuber samples caused a percentage increase in the tuber samples’ reducing sugar level from 12.5 to 63.90%. Thus the mean levels of the reducing sugar in the no bruised, scantily bruised and heavily bruised tuber samples were statistically significant. 2.85±0.46, 2.53±0.12, 2.27±0.08, 2.14±0.06 and 3.31±0.42 mg/g were the mean levels of reducing sugar in the potato tuber samples blanched at temperatures and times of 45oC, 55oC, 65oC, 80oC and 0oC and 4min, 8min, 12min, 16min and 0min respectively. Increase in blanching temperature and time from 45 to 80 oC and 4 to 16min respectively caused a 9.81 to 32.91 % reduction of the mean reducing levels of the potato tuber samples. From the physical observation of the tuber samples after blanching, the ideal range of blanching temperature and time for decreasing the reducing sugar levels in potato tubers prepared for quality crisp production was at 55 to 65oC and 8 to 12 min respectively.
Keywords Reducing sugar, Blanching, Potato tubers and Potato tuber bruises.