Evaluation of wheat kernel and flour quality as influenced by chlorine dioxide gas treatment

Chlorine dioxide (ClO2) gas, known for its high oxidation and penetration capacity, is a potential alternative fumigant to control stored-product insect pest population. In this study, hard red spring wheat (Triticum aestivum L.) kernels were exposed to varying levels of gaseous ClO2 concentrations (200, 300, 400, and 500 ppm, 1 ppm = 0.0027 mg/L at room condition) and held in a gas-tight bucket assembly for 24 h after achieving desired concentration. ClO2 treatment achieved complete insect mortality of lesser grain borer (Rhyzopertha dominica (Fabricius)) and highest adult progeny reduction at 500 ppm across all vial locations. Significant reduction (37.8-51.1%) in germination percentage resulted after exposure to 300-500 ppm. Flour lightness value significantly increased after kernel treatment at 200-500 ppm. The pH value of wheat flour was significantly reduced from 6.2 to 6.1 after 500 ppm treatment. Peak and final viscosities of wheat flour significantly decreased from 3303.7 to 3073.3 cP, and from 3515.0 to 3208.3 cP, respectively. No significant difference was observed in other investigated flour quality and functionality parameters, including falling number, trough viscosity, breakdown viscosity, starch damage, and Mixolab dough behavior properties. Overall, ClO2 treatment at 500 ppm is effective in killing adult lesser grain borers without negatively affecting wheat flour quality parameters.