Physicochemical characteristics of sweet corn kernels during microwave blanching

Abstract

Sweet corn kernels are easily perishable because of their high amount of moisture content. Microwave blanching was applied at the power level of 180–900 W for 30–70 s to inactivate the enzymes of sweet corn kernels. The increase in microwave power level and processing time reduced the length from 11.13 to 10.78 mm, width from 9.54 to 9.24 mm, thickness from 4.01 to 3.71 mm, true density from 1052.07 to 1012.03 kg/m3, porosity from 37.43 to 24.54%, moisture content from 70.00% to 68.93% on a wet basis, total soluble solid from 22.3 to 18.7 °Brix, total sugar from 8.80% to 6.67%, ascorbic acid from 8.04 to 5.92 mg/100 g, and peroxidase activity up to 1.37% in sweet corn kernels, but it increased the bulk density from 658.23 to 763.6 kg/m3 and total color difference up to 14.55. Novelty impact statement The microwave blanching was found adequate for processing sweet corn kernels at the power level of 720 W for a short duration of 40 s to achieve a 90% reduction in peroxidase activity. The ascorbic acid, total sugar, overall acceptability after the microwave blanching were 6.86 mg/100 g, 7.87%, and 8.21, respectively, indicating 85, 89, and 94% retention of fresh samples properties. The total plate count was 9.1 log cfu/g in fresh kernels, which was also reduced to 1.8 log cfu/g in kernels blanched at the power level of 720 W for 40 s duration.