FR2660528A1 - Method for preparing precooked (ready-prepared) dishes based on vegetable products - Google Patents

Abstract

Method for preparing precooked dishes based on vegetable products alone or with a meat accompaniment, characterised in that cooking takes place in a carbon dioxide atmosphere. The cooking temperature ranges between the order of 50 DEG C and the order of 130 DEG C, while the pressure of the carbon dioxide gas is chosen from a wide range extending from a pressure below atmospheric pressure up to 20 bar.

Description

 The invention relates to the preparation of cooked or pre-cooked ready meals based on plant products, alone or with a meat side dish product.

 Such ready meals, sold ready to use in refrigerated shelves, are more and more appreciated by consumers.

 Until now, such ready meals have generally been prepared by vacuum cooking. However, the sterilization sanitary constraints and the distribution logistics on standby refrigerated over several days lead manufacturers to implement high cooking temperatures little lower than 100cl and commonly 950C and extended durations of heat treatment which extend over a period to tweak the hour. This technique therefore makes it possible to respect the sanitary quality of cooked dishes and this for an appropriate period of refrigerated storage, but to the detriment of the gustatory quality of plants which lose, during cooking, their "crunchy" texture, which represents an important aspect. for the consumer.

 The present invention relates to the preparation of such cooked dishes based on plants, where the plants retain, at the end of the heat treatment and during a refrigerated storage period, their crunchy texture and this object of the invention is achieved in that the cooking is carried out under an atmosphere of carbon dioxide. The pressure of the carbon dioxide can be chosen over a wide range of pressures, from a pressure below atmospheric pressure (according to the compensated vacuum technique) to overpressures of up to 20 bars.

 The cooking temperature can be very variable in a range of around 500C to around 1300C, depending on the plants concerned.

 Experience shows that the atmosphere of carbon dioxide makes it possible to better preserve the texture of a plant subjected to a heat treatment, and moreover to improve the thermal destruction of microorganisms in vegetative and spore form. Finally, a carbon dioxide atmosphere also improves the thermal inactivation of enzymes, which can be detrimental to the good preservation of the product sold (eg enzymatic browning).

 The invention is now illustrated by the following verification tests a) Effect of a CO 2 atmosphere on the texture of cooked plants.

Oh has zucchini, branched broccoli and white
fresh leeks. Zucchini and leeks are
cut into rings, the broccoli into small branches, which are
arranged in aluminum aerosol cans, in which there are
added salt water until the products are completely immersed.
aerosol cans were then sealed with valves
crimped. We then proceeded to share the aerosol cans in
several lots for each product
- a batch kept as it is (in air at atmospheric pressure
(200C)
- a batch has been evacuated (200C)
- a batch was pressurized under 6 bar of oe2 (200C)
- a batch was put under vacuum then pressurized under 6 bar of CO2
(200C)
- a batch has been put under vacuum compensates for oe2 until obtaining
atmospheric pressure (20OC).

These samples were then immersed in an aqueous medium
regulated at 95 OC.

Such heat treatment applied were respectively
- 70 mins for broccoli
- 80 min for the white leeks
- 50 fln for zucchini
After cooking, the aerosol cans were quickly cooled
by soaking in OOC water before opening.

The cooked products obtained can be classified into two categories
- the first category includes products cooked under a
air or vacuum atmosphere. The products obtained have a texture
very soft.

- the second category includes all products cooked under a
atmosphere containing 2 In this case, the products retain
a crunchy texture all the more persistent as the pressure
conditioning at 200C is high. The only minor downside
is that green products tend to turn yellow.

This may be acceptable for certain products (eg zucchini),
but this drawback can be reduced or even eliminated by adding
magnesium sulfate at a rate of 0.5 g / liter of cooking product.

b) Effect of a pressurized CO2 atmosphere on destruction
thermal in vitro spores of Bacillus stearothermophilus.

5 ml samples of Ringer containing approximately 105 spores of
B. stearothermophilus per ml were distributed in vials in
glass with a capacity of 16 ml each. The bottles have been closed
hermetically by valves. Some of these vials have been
used as is, i.e. with air as the atmosphere of the sky
gaseous at 200C and atmospheric pressure. The other party doing
pressurized under 6 bar of oe2 at 200C.

The samples were then subjected to heat treatments
in an aqueous medium at different temperatures (950C, 100OC, 1050C)
for different durations.

For each test, the spores still viable after treatment
were counted after dilution and spreading in boxes
kneaded on an agar medium allowing the germination of spores.

 An incubation of several days at 550C was necessary.

As shown in the attached graph of the attached results (TDT =
'Ithermel death time ", where we plotted the decimal logarithm of
ratio N = number of persistent living spores after
treatment / ml on NO = number of initial spores / ml depending on the
treatment time at the studied temperature), efficacy
destructive of the heat treatment spores is clearly
improved in the presence of oye2. We can note on this curve, that a
treatment under atmosphere from oe2 to 950C is equivalent to treatment
in air at a temperature above 1050C.

Such cooked dishes, or pre-cooked, are suitable for preservation. When they have been prepared in airtight packaging, they can be stored in this same repackaging incorporating an atmosphere of carbon dioxide, which has only been, if necessary, depressurized. If the cooking or pre-cooking treatment has taken place on bulk products, conservation can be ensured by then placing them in a packaging under conservation atmosphere, which can be carbon dioxide under moderate pressure or under pressure. atmospheric, or another gas or gas mixture more suitable for the preservation of cooked or pre-cooked products, such as
CC2, N20, N2 or a mixture of these gases, if necessary with an additional low oxygen content.

 It goes without saying that these storage methods can be applied to products whose cooking, or pre-cooking, in packaging, if necessary by substituting the carbon dioxide for cooking with another gas or gaseous mixture as mentioned above.

Claims (6)

 1. Process for preparing cooked or pre-cooked cooked dishes based on vegetable products alone or with a meat accompanying product, characterized in that the cooking is carried out under an atmosphere of carbon dioxide.  2. Method for preparing cooked or pre-cooked cooked dishes, according to claim 1, characterized in that the cooking temperature is between about 500C and about 1300C.  3. Process for preparing cooked or pre-cooked cooked meals, according to claim 1 or 2, characterized in that the pressure of the carbon dioxide is chosen from a wide range extending from a pressure below atmospheric pressure to 20 bars.  4. Method for preparing cooked or pre-cooked cooked dishes, according to any one of claims 1 to 3, characterized in that the cooking time is of the order of 50 min to about 80 min, depending the plant concerned.  5. Process for the preparation of cooked meals pre-cooked, according to any one of claims 1 to 4, characterized by the addition of magnesium sulfate in an amount of 0.5 g / liter of cooking product.  6. A method of preparing cooked or pre-cooked cooked dishes, according to any one of claims 1 to 5, characterized in that it provides preservation in an atmosphere consisting of oe2 and / or N20 and / or N2, the if necessary with a low oxygen content.