WO2003011038A2

WO2003011038A2 - Process for controlling pests in agrifood products by means of high-pressure carbon dioxide

Info

Publication number: WO2003011038A2
Application number: PCT/IB2002/002999
Authority: WO
Inventors: Jordi Riudavets Muñoz; F. Javier Sanchez Molino; Cristina CASTAÑE FERNANDEZ; Rosa Gabarra Ambert
Original assignee: Sociedad Espanola de Carburos Metalicos SA
Current assignee: Carburos Metalicos SA
Priority date: 2001-07-31
Filing date: 2002-07-29
Publication date: 2003-02-13
Anticipated expiration: 2004-01-31
Also published as: ES2186559A1; AU2002355681A1; WO2003011038A3; ES2186559B1

Abstract

Process for controlling pests in agrifood products by means of a high-pressure CO2 treatment. The process comprising three steps: a first step in which the pressure of the CO2 is increased to 15-20 atmospheres, at a temperature ranging from 15 to 40 °C; a second step in which the pressure is maintained for 15-120 minutes; and a third step in which the pressure is lowered over a time ranging from 0.5 minutes (swift release) and 10 minutes (slow release), giving temperatures ranging from 10 to 30°C in the case of slow release, and from -15 to +8°C in the case of swift release.

Description

PROCESS FOR CONTROLLING PESTS IN AGRIFOOD PRODUCTS BY MEANS OF HIGH-PRESSURE CARBON DIOXIDE

State of the art The present invention relates to a process for controlling pests in agrifood products by means of treatment involving C0₂. This process enables insects to be eradicated at any stage of their development.

Prior Art

There are many documents in the state of the art describing the use of C0₂ for eradicating pests in agrifood products.

Patents such as EP-A-O417430 (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 C0₂ used as a carrier for the disinfecting agent.

Furthermore, there are publications that describe the use of C0₂ 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. ohlgemuth 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 C0₂, 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 C0₂ 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:

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 C0₂ 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:

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

Claims

C L A I M S

1. Process for controlling pests in agrifood products by means of a high-pressure C0₂ 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) .

2. Process according to claim 1, characterized in that step (a) is performed at a temperature ranging from

15 to 40 °C.

3. Process according to claim 1, characterized in that when slow decompression is arranged for step (c) , the temperature ranges from 10 to 30 °C.

4. Process according to claim 1, characterized in that when swift decompression is arranged for step (c) , the temperature ranges from -15 to +8 °C.

5. Process according to any of the preceding claims, characterized in that the insect to be eradicated is a Lepidopteran.

6. Process according to claim 5, characterized in that the insect to be eradicated is preferably Plodia interpunctella .

7. Process according to any of the preceding claims, characterized in that the insect to be eradicated is a Coleopteran.

8. Process according to claim 7, characterized in that the insect to be eradicated is selected from among Tribolium castaneum, Sitophilus oryzae, Acanthoscelides obtectus and Lasioderm serricorne.