New Postharvest Methyl Bromide Substitute Process Developed
A new method for ridding harvested fruits and vegetables of insect pests and microorganisms, without the use of ozone-depleting chemicals such as methyl bromide, has been developed by researchers at the University of California-Davis.
The technique, called metabolic stress disinfection and disinfestation, effectively suffocates insects found in harvested produce. Inside sealed chambers, alternating vacuum forces and pressurized carbon dioxide applications cause irreversible changes in the pests’ cell chemistry and respiratory structures. Ethanol gas also is applied briefly to accelerate killing of fungi and bacteria and to damage insect eggs.
In practice, the process would be applied to pallets of fruits and vegetables to prevent insect damage during storage and shipping, and to avoid transporting potentially invasive insects from one country to another.
A patent is pending on the technology. All major fruits and vegetables retain their quality when treated, said the developer, Manuel Lagunas-Solar, a research chemist at the university’s Crocker Nuclear Laboratory. The process also controls spoilage and insect pests in dried fruits, grains and nuts.
Only a few soft-tissue fruits, such as raspberries and blackberries, do not take the treatment well. The researchers hope that the new technique will become a permanent substitute for methyl bromide, which was scheduled for phase-out in 1997, but is still used because of a lack of feasible alternatives.
|
