Nitric oxide fumigation for the control of microorganisms on stored products

Authors: OH, SOOKYUNG - University Of California; Liu, Yong Biao

Submitted to: Methyl Bromide Alternatives and Emissions Research Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/12/2019
Publication Date: 11/3/2019
Citation: Oh, S., Liu, Y.-B. 2019. Nitric oxide fumigation for the control of microorganisms on stored products. Proceedings of MBAO: Fumigation and Alternatives for Production, Storage and Trade Conference, 53-1, November 11-13, 2019, San Diego, California.

Interpretive Summary:

Technical Abstract: Nitric oxide (NO) is effective for postharvest pest control. NO reacts with O2 spontaneously to produce nitrogen dioxide (NO2), thus NO fumigation must be conducted under ultralow oxygen (ULO) conditions. NO2, which has antimicrobial properties. NO fumigation can be carried out with controlled O2 levels in order to have specific concentrations of NO and NO2, and therefore, has commercial potential for control of insects and microorganisms on stored products. We evaluated the microbicidal effects of NO2 fumigation on Aspergillus flavus spores on nitrocellulose membranes, microbial loads on unpasteurized almond kernels and unpasteurized unshelled peanuts. Fumigations with 0.1% NO2 for 3 h at 15°C resulted in complete control of A. flavus spores. Fumigations with 0.1%, 0.3%, or 1.0% NO2 for one or three days at 25°C greatly reduced microbial loads on almonds. Three-day fumigation with 0.3%, 1.0%, or 3.0% NO2 at 25°C significantly reduced microbial loads on peanuts. NO fumigation with controlled concentrations of NO and NO2 has commercial potential to control of both pests and microbes on stored products.