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

Authors: BUENAVISTA, RANIA - Kansas State University; E, XINVI - Kansas State University; SUBRAMANYAM, BHADRIRAJU - Kansas State University; RIVERA, JARED - Kansas State University; Casada, Mark; SILIVERU, KALIRAMESH - Kansas State University

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2023
Publication Date: 5/18/2023
Citation: Buenavista, R.M., E, X., Subramanyam, B., Rivera, J.L., Casada, M.E., Siliveru, K. 2023. Evaluation of wheat kernel and flour quality as influenced by chlorine dioxide gas treatment. Journal of Stored Products Research. 102. Article 102127. https://doi.org/10.1016/j.jspr.2023.102127.
DOI: https://doi.org/10.1016/j.jspr.2023.102127

Interpretive Summary: There is an increasing need for alternative fumigants to replace methyl bromide and provide options for controlling stored-product insect pests, especially those that have become resistant to the common fumigant phosphine. Chlorine dioxide (ClO2) gas can easily penetrate tissues and cells from living organisms and cause irreversible oxidative damage, suggesting it can be an effective alternative fumigant. We evaluated the efficacy of ClO2 by exposing hard red spring wheat kernels infested with lesser grain borers (LGBs) against concentrations of ClO2 ranging from 200 to 500 ppm. We also assessed flour quality parameters to determine whether fumigation would negatively impact milling and end use. Results showed that the 500 ppm ClO2 level was required to achieve complete adult insect mortality and minimize surviving eggs that develop and lead to reinfestation. There was a significant reduction in germination rate for all but the lowest ClO2 level, indicating ClO2 fumigation may be problematic for seeds intended for field planting or for malting. Although there were minor changes in flour lightness value, pH, and the peak and final viscosities of flour produced from ClO2-treated wheat kernels, none of those changes were significant enough to preclude ClO2 for use as a fumigant on wheat. There was also little to no change in milling results after ClO2 treatments, indicating that flour from ClO2-treated wheat should be suitable for marketing and incorporation into a variety of food products. Overall, ClO2 treatment at 500 ppm was effective in killing adult LGBs without adversely affecting wheat flour quality parameters and shows promise as an alternate fumigant for stored product insect management.

Technical Abstract: 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. Three vials containing 20 unsexed adults of lesser grain borer (Rhyzopertha dominica (Fabricius)) were placed at top, middle, and bottom layers of wheat mass during fumigation for insect mortality assessment. ClO2 treatment achieved complete insect mortality and highest adult progeny reduction at 500 ppm across all vial locations. Significant reduction (37.8-51.1%) in germination rate resulted after exposure to 300-500 ppm. Flour lightness value significantly increased (p < 0.05) after kernel treatment at 200-500 ppm. The pH value of wheat flour was significantly reduced (p < 0.05) from 6.2 to 6.1 after 500 ppm treatment. Peak and final viscosities of wheat flour significantly decreased (p < 0.05) from 3303.7 to 3073.3 cP, and from 3515.0 to 3208.3 cP, respectively. No significant difference (p > 0.05) 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.