Potential detection and quality properties of gamma-irradiated corn starch of korean and chinese origins by viscosity measurement during storage

摘要

Physicochemical changes in corn starch caused by irradiation were investigated, and irradiated samples were identified. Viscosity, TBA value, Hunter color, and total viable count were measured after irradiation of corn starch. Corn starches from Korea and China were irradiated at 0, 2.5, 5, 7.5, 10, and 15kGy using a Co~(60) irradiator and stored for 9 months at 0 deg C and 20 deg C. Viscosity and specific parameter values decreased in all samples with increasing irradiation dosage at 50 rpm, showing a dose-dependent relationship (above R~2=0.80) between non-irradiated and irradiated samples during storage. These results suggest that detection of irradiated corn starches is possible using viscometric method during storage. Total viable count, TBAvalue, and Hunter color were determined as supplemental indices for measuring viscosities of samples. Total viable count and TBA values showed dose-dependent relationship (2.5-15 kGy). Differences in viscosity and total viable count, and TBA values amongnon-irradiated samples showed little changes with the lapse of post-irradiation time, but were still distinguishable for more than 6 months at 0 deg C and 20 deg C for corn starches from Korea and China.