FR2650942A1 - Process for inactivating food-spoilage enzymes - Google Patents

Abstract

Process for inactivating food-spoilage enzymes by heating, characterised in that the said heating for enzyme inactivation is performed under a confined gaseous atmosphere under pressure with an initial carbon dioxide and/or nitrous oxide component. Application to the blanching and/or cooking of foods at low temperature.

Description

 The present invention relates to the process of inactivating the enzymes of deterioration of food by heating, cooking or acronym "bleaching".

 Q1 knows that the "bleaching" of plant foods is mainly aimed at the inactivation of certain enzymes (catalase, peroxidase, lipase, amylase, lipoxygenase, protease, polyphenoloxidase, chlorophylase, etc ...) responsible for unwanted deterioration phenomena during l storage of frozen, dehydrated or cooked products at a low temperature.

 This treatment ensures a better hygienic quality of the food and also helps to disperse the dissolved gases in the cell compartments, thus reducing the subsequent risks of oxidative reactions.

 On the other hand, even a very slightly excessive heating (long duration / high temperature pair) usually causes degradation of the texture of the treated plants.

 Recent techniques of conservation in fresh (0-40CZ) and low temperature cooking show problems of enzymatic deterioration during the conservation (vegetables, meat, fish ...) For example the low temperature cooking of fish fillets ( 58CC), if it makes it possible to obtain an excellent organoleptic quality, does not ensure the enzymatic stability of the product (active proteases), since the time / temperature pairing remains insufficient.

 The objective of the present invention is - first, and in general, to reduce the torques (duration, terperature) of the firing or bleaching treatments necessary for the inactivation of the deterioration enzymes, in order to reconcile a good organoleptic quality (texture, taste, flavor ...) with the need for long shelf life of the product - and, in some cases, to implement a technique that can be used with the same torque (time, temperature) that that defined for conventional treatment, but resulting in a more efficient inactivation of enzymes.

 This object according to the invention is achieved in that said enzyme inactivation heating is carried out in a gaseous atmosphere confined to an initial gas component. carbonic and / or nitrous oxide. This initial atmosphere composition may be exclusively carbon dioxide, or nitrous oxide, or a mixture of carbon dioxide and nitrous oxide.

 The results of the invention are now explained with reference to the appended drawing, which represents records of the activity of an enzyme ("horseradish peroxidase") (initial activity 0), as a function of time t representing the durations of heating, for three atmospheres: air at atmospheric pressure (curves 1), carbon dioxide (6 bar at 20 ° C) (curves 2) and nitrous oxide (6 bar at 20 ° C) (curves 3) for different temperatures (90 ° C., 90 ° C. , IOOOC).

2H2O + D (1) dans laquelle est est une solution "D" est un réactif coloré
de guaiacol d'absorbance à 436 nm
La cinétique d'apparition du produit "D" a été mesurée å l'aide d'un spectrophotomètre (absorbance à 436 nm).The residual activities of the treated enzymes were characterized by the initial rate of kinetics of the following reaction catalyzed by peroxidase
roe (peroxidase) 11202 +

2H2O + D (1) where is is a solution "D" is a colored reagent
of absorbance guaiacol at 436 nm
The kinetics of appearance of the product "D" was measured with the aid of a spectrophotometer (absorbance at 436 nm).

The intensity of the inactivation treatment of the enzyme was expressed by the parameter ln

<SEP> Vi
<tb> Vio
<tb> wherein - Vi is the initial rate of the reaction (1) characterizing the residual activity of the enzyme treated for a given triplet (time, temperature, atmosphere).

Vio being the initial rate of reaction (1) characterizing the activity of the untreated enzyme (control).

 With reference to the drawing, it can be seen that oe2 and, to a lesser extent, N2O, make it possible to obtain a more effective enzymatic inactivation for the same time / temperature pair.

 The in vitro experiment on peroxidase, which is considered to be the most heat-resistant food spoilage enzyme, demonstrates the inactivation of most of the undesirable enzymes present in food by a moderate heat treatment under carbon and / or nitrous oxide.

 The invention is applicable to all foods subject to the so-called treatment whitening or cooking moderate pace.

Claims (5)

REVENDICATINS  A method of inactivating food degrading enzymes by heating, characterized in that said enzyme inactivation heating is carried out in a gaseous atmosphere confined under pressure with an initial component of carbon dioxide and / or nitrous oxide .  2. Enzymatic inactivation process according to claim 1, characterized in that the initial gaseous atmosphere under pressure consists exclusively of carbon dioxide.  3. Enzymatic inactivation process according to claim 2, characterized in that the initial gaseous atmosphere under pressure consists exclusively of nitrous oxide.  4. Process for the inactivation of enzymes according to claim 2, characterized in that the initial gaseous atmosphere under pressure consists exclusively of a mixture of carbon dioxide and nitrous oxide.  5. Enzymatic inactivation process according to any one of claims 1 to 4, characterized in that the initial gas component gas pressure of carbon dioxide and / or nitrous oxide is of the order of 6 bar to 20cl.