Sterilisation method sucks life out of bugs

The technique could replace the use of post harvest pesticides, and may help the industry complete the phasing out of ozone depleting methyl bromide.

In 1997, 160 governments promised to phase out the use of methyl bromide by 2005 as part of the Montreal Protocol agreement. Some exceptions were granted for the food and farming industries.

The technique is called metabolic stress disinfection (MSDD). It works by subjecting insects on fruit and vegetables to alternating vacuum and carbon dioxide treatments.

This effectively suffocates organisms because they require oxygen to live. Ethanol gas is also used to kill fungi and bacteria.

Manuel Lagunas-Solar and a team of scientists at the University of California describe the new method in a report published in the Chemistry & Industry.

Tim Essert, the principle electronics engineer on the project, told Chemistry & Industry magazine that the initial hardware cost of an MSDD system is higher than methyl bromide, but the cost of chemicals is much cheaper.

The system would eventually it would pay for itself, he claimed.

About $20 to $40 worth of methyl bromide is needed to fumigate one pallet of fruit, the scientists estimate. Carbon dioxide and ethanol used in an MSDD treatment would cost about $10, assuming no recovery of the gasses for further use.

"MSDD also has additional benefits to the environment, as the gasses can be recovered and recycled,"​ the scientists stated.

The scientists original paper, "Metabolic stress disinfection and disinfestation (MSDD): a new, non-thermal, residue-free process for fresh agricultural products", was first published in the Journal of the Science of Food and Agriculture.