Prior Art There are many documents in the state of the art describing the use of CO2 for eradicating pests in agrifood products.

Patents such as EP-A-0417430 (validated in Spain as ES-2035687) and EP-0416255 describe installations for disinfecting organic material (agrifood products such as cereals etc. ) featuring C02 as the disinfecting agent.

Patent GB-1536170 describes, among other aspects, a method for fumigating cereals in which the disinfecting agent is methyl bromide and being COs used as a carrier for the disinfecting agent.

Furthermore, there are publications that describe the use of CO2 for eradicating certain insect pests when the pests are at a particular stage of their development.

The article"Carbon dioxide under high pressure of 15 bar and 20 bar to control the eggs of the Indianmeal moth Plodia Interpunctella (Hubner) (Lepidoptera Pyralidac) as the most tolerant stage at 25°C"by Reichmuth and R.

Wohlgemuth describes certain conditions of constant- temperature (25°C), C02 pressure (20 to 40 bar) and treatment time (ranging from 8 to 15 hours depending on the type of insect) suggesting potential use in the

eradication of the insect Plodia Interpunctella at the egg stage.

The publication"The use of high pressure carbon dioxide (20 bar) to control some insects of foodstuff", by Daria Patrizia Locatelli, Luciano Suss and Maurizio Frati, describes the use of carbon dioxide for eradicating various insect pests at various stages in their lives, and the publication highlights as critical features, along with the pressure of the carbon dioxide, the concentration of the gas and the swift discharge of the gas at the end of the treatment.

In addition, the use of products such as methyl bromide for eradicating insects at any stage of their development is well known in the state of the art. The main problem with those products is their high toxicity and the lengthy treatment time involved.

In the food industry, it is of particular interest to have products such as flours, cereals etc. fully disinfected, so that insects will not bring about the deterioration of those products.

Advantageously, this invention relates to a process for controlling pests in agrifood products by treatment with CO2, the process enabling pests to be eradicated regardless of the stage the insects have reached in their life cycles.

Description of the specification The present invention relates to a process for controlling pests in agrifood products by means of a pressure C°2 treatment comprising the following steps:

a) Increasing the pressure of the C02 to 15-20 atmospheres. b) Maintaining the pressure for 15-120 minutes. c) Lowering the pressure in a time of between 0.5 minutes (swift release) and 10 minutes (slow release).

Advantageously, the process of this invention enables pests to be eradicated regardless of their stage of development.

Step (a) -increasing the pressure (compression)- is performed inside an autoclave connected to a cryogenic tank loaded with liquid carbon dioxide. Depending on the pest concerned, a pressure of 15 atm is to be reached, requiring a time of five and a half minutes, or 20 atm, requiring a time of some 10 minutes. The compression step is performed at a temperature ranging from 15 to 40 °C.

In step (b) of the process, the pressure attained in the previous step is maintained.

In step (c)-the decompression step-the pressure is reduced down to atmospheric pressure over a period of time ranging from 0.5 minutes (swift decompression) to 10 minutes (slow decompression).

When slow decompression is arranged, the temperature ranges from 10 to 30 °C ; in the case of swift decompression, the temperature ranges from-15 to +8 °C.

Advantageously, the process of this invention does not require any additional system for keeping the temperature at a set value for each step, since in the process of the invention, the temperatures that

characterise each step result from the compression/decompression phenomena carried out inside the autoclave.

Preferred embodiment of the invention The insects used in the tests described below were bred in such a way as to contain specimens from all the stages in the life cycles of each species.

Insectation was arranged in aerated plastic boxes (7.5 cm in diameter and 3 cm high) containing 20 grams of the food substrates usually employed in breeding pests: PEST Breeding substrate Plodia Interpunctella Bran of wheat + glycerine + brewer's yeast Tribolium castaneum Flour + brewer's yeast Sitophilus oryzae Rice Acanthoscelides obtectus Dried kidney beans Lasioderma serricorne Flour + brewer's yeast After 24 hours of initial insectation, the boxes were placed in an autoclave with a capacity of 0.25 m3, connected to a cryogenic tank (with CE marking, model 2000-23) loaded with liquid carbon dioxide.

Next, the compression step was arranged, bringing the CO2 up to a pressure of between 15 and 20 atm and the temperature up to between 15 and 40 °C.

The pressure was then maintained for 15-90 minutes, before the time of the final decompression step.

The pressure set during the first step and the length of the treatment time depend on the degree of resistance to the treatment exhibited by each of the pests. In this way, the specific conditions for each of the pests studied were found, they being: Pressure Treatment Decompression (atm) time time P. 15-20 15'-60'0. 5'-10' interpunctella T. castaneum 15-20 30'-60'0. 5'-10' S. oryzae 20 60'0. 5' A. obtectus 20 60'0. 5' L. serricorne 20 120'0. 5'

Under the conditions found for each of the pests, total eradication was achieved regardless of the stage of development of the insects.