Food Technology Information Center

V-HF or Vacuum Hermetic Fumigation

The use of low pressures to control insects in post-harvest storage has been studied in the past. It was shown that mortality is caused mainly by the low partial pressure of oxygen that results in hypoxia and also dehydration due to removal of water vapor under vacuum.

Until recently, the possibility of using low pressures at the large scale commercial level to control insect infestations had been abandoned due to the requirements for massive, rigid and expensive structures needed to withstand the low-pressures.

Recently however a new and innovative technology was introduced by members of our team for the hermetic storage of durable commodities, and is now in use on an industrial scale. The structures consist of flexible plastic chambers with manufacture specifications to a level of gas tightness that also enables treatments with modified atmospheres or fumigants without significant gas loss over short exposure times. These structures are termed "GrainPro Cocoons".

It has now been shown that these "cocoons" can be adapted take the place of such rigid vacuum chambers. To achieve the low pressures in the flexible liners, sufficiently low pressures (25-50 mmHg absolute pressure) can be obtained using a commercial vacuum pump and maintained for indefinite periods of time.

Work on this innovative technology is ongoing but further information may be obtained through FTIC's publications.