WO2012001314A1

WO2012001314A1 - Artificial mouth simulating chewing, and a method for analysing compounds that lead to sensory perception, in particular flavours, using one such artificial mouth

Info

Publication number: WO2012001314A1
Application number: PCT/FR2011/051530
Authority: WO
Inventors: Gaëlle ARVISENET; Carole Prost; Pauline Poinot
Original assignee: Ecole Nationale Vétérinaire, Agroalimentaire Et De L'alimentation, Nantes-Atlantique
Priority date: 2010-07-01
Filing date: 2011-06-30
Publication date: 2012-01-05
Also published as: FR2962246B1; EP2589038A1; FR2962246A1

Abstract

The invention relates to an artificial mouth including a hermetically sealed chamber (1) in which food (6) is placed between two plates (4, 5) which move relative to one another and which are designed to break down the food by simulating chewing. A flexible membrane (19), linked to the movement of one of the plates, mimics the inflation of the cheeks and, combined with a constant gas stream, promotes the release from the food of volatile compounds responsible for the flavour of said food. The artificial mouth, which simulates both human chewing and breathing, can be connected to an olfactory cone (24) and/or to a trapping device and/or to a chromatograph, allowing analysis of the compounds that lead to the sensory perception of flavours.

Description

ARTIFICIAL MOUTH SIMULATING THE MASTICATION AND METHOD OF ANALYZING THE COMPOUNDS ORIGINATING IN SENSORY PERCEPTION, ESPECIALLY AROMAS, IMPLEMENTING SUCH AN ARTIFICIAL MOUTH

The present invention relates to the field of devices for the study of phenomena involved in the mastication of food, and more particularly to an artificial mouth for mimicking human mastication in vitro, as well as a method for analyzing compounds at the origin of the sensory perception of food, especially the aroma of food.

BACKGROUND - STATE OF THE ART

The perception of the aroma of a food is a complex and dynamic phenomenon, which involves several steps involving volatile compounds. As soon as the food is placed in the mouth, then during its mastication, volatile compounds are released from the latter and pass into the gas phase. They are then transported from the oral cavity to the nasal cavity, where they interact with the receptors present in the olfactory epithelium. The set of nerve signals, resulting from the interaction of the multiple volatile molecules of the food with different olfactory receptors, is then integrated in the central nervous system. The treatment of the resulting nerve information then results in a sensory image corresponding to the aroma of the food placed in the mouth.

In order to study the volatile compounds responsible for the aroma of food, different techniques (sensory and instrumental) were used. Among these, artificial mouth prototypes have been developed, firstly to artificially reproduce the process of destructuring food in vivo, in order to extract the compounds responsible for the aromas under conditions as close as possible to the conditions. actual consumption of said foods. However, most of these artificial mouth prototypes are only suitable for liquid or semi-solid foods.

For the simulation of solid food chewing, the inventors have already proposed (Arvisenet et al., J. Agric Food Chem., 2008, 56, 3245-3253) an artificial mouth for destructuring relatively hard solid foods, such as for example, bread or apples. This artificial mouth is based on the principle of mechanical destructuring of food to be studied between a pair of trays animated relative movements.

It comprises a hermetically sealed thermostatic chamber in which are arranged two parallel plates animated relative movements with respect to each other, on the one hand, a rotatable lower plate intended to support said foods to be studied, and, on the other hand, on the other hand, an upper plate, equipped with teeth, affecting the shape of a piston animated by a vertical reciprocating movement.

The enclosure is further equipped with a gas inlet, and a gas outlet opening in the lid to drive the volatile compounds released during the deconstruction of food between the two trays to this end. orifice. It is thus possible to place a probe for capturing said volatile organic compounds released during this mechanical chewing.

The upper tray makes vertical back-and-forth movements that mimic chewing movements, and the lower rotatable tray mimics the repositioning of the food under the teeth.

These two movements are preferably provided by two separate motors, which allows to control their respective speed.

The presence of the teeth and the combination of these two movements allow a complete destructuring of hard foods, for example apples.

The flow of gas makes it possible to drive volatile compounds extracted from the destructured feedstocks to, for example, a SPME fiber (solid phase microextraction) on which they are trapped, for subsequent analysis by GC-MS / FID. It is important that this gas does not escape from the chewing simulator at other locations than the lid opening for this function. For this, a perfect seal is necessary. The latter is difficult to reconcile with the different movements of the moving elements, including the upper plate forming a piston.

The volatile molecules trapped by the SPME sensor for a given duration are then analyzed. This analysis therefore gives sequential results (by mastication time slices) but does not provide information on the nature and quantity of volatile compounds emitted at each instant, and therefore of their variation over time. Such a device therefore does not allow to acquire direct sensory information on liquid (saliva) or gaseous fractions throughout their release.

It is, indeed, necessary for a complete study of the aromas to be able to compare the chemical analysis of the various volatile compounds released during the mastication and the sensory parameters perceived by the individuals during the consumption of said foods.

A first object of the present invention is therefore to develop an artificial mouth to overcome the above drawbacks, and more particularly to mimic the mastication, as well as the breathing phenomena involved in the transport of volatile compounds, responsible for aromas said food, from the oral cavity to the nasal cavity when chewing in a human mouth.

Another object of the invention is to limit gas leakage from the enclosure of the artificial mouth, except the outlet through the orifice provided for this purpose.

DESCRIPTION OF THE INVENTION

For this purpose, the present invention relates to an artificial mouth for the study of phenomena (physicochemical and / or biochemical) occurring during the chewing food, especially the study of food flavors, in particular solid foods, comprising an enclosure, preferably with thermally closed walls, hermetically closed by a lid, in which are arranged two substantially parallel plates, animated by relative movements; relative to each other, able to reproduce the masticatory movements of destructuring food arranged between them: on the one hand a lower tray intended to support said food to be studied, and on the other hand an upper tray disposed above the lower plate and whose face vis-à-vis the lower plate is equipped with a plurality of rows of teeth, said upper plate and the rod to which it is secured constituting a piston driven by a vertical reciprocating movement, and said lower plate is rotatably able to mimic the repositioning of food (by the tongue) under the teeth, said e enclosure being further equipped with a gas inlet and a gas outlet orifice in or near the lid, a gas flow being capable of driving the volatile compounds, released during the destructuring of food between the two trays, towards said outlet orifice, in order to allow the analysis at the outlet of said volatile compounds, responsible for the aroma of said foods, characterized in that the lid consists of a flexible membrane, the periphery of which is firmly secured impervious to the walls of the enclosure, and whose central portion is raised and lowered alternately depending on the movements of the upper plate or depending on the gas flow, leading to sequential changes in the volume of the enclosure, mimicking the breathing and alternating swelling of the cheeks during chewing.

Thus, the presence of the flexible membrane coupled to the vertical reciprocating movement of the upper piston allows volume variations of the enclosure by mimicking the swelling / deflation of the cheeks of a human mouth during mastication, while ensuring the necessary seal . This presents a important advantage over the constant volume chamber of the prior art.

Advantageously, a coaxial disc carried by the rod of said piston, upper stopper shape of the membra ne during its swelling, and optionally serves as training means / or accompanying said membrane during its lowering.

According to a first variant of the invention, the central portion of the membrane and the coaxial disk are integral with the piston rod, the movements of said piston imposing the swelling and lowering of the membrane.

In this first variant, the inlet gas flow is advantageously a continuous flow. This flow then becomes sequential at the output as a function of the volume variations of the enclosure, imposed by the vertical displacement of the central part of the membrane forming the enclosure cover, secured to the piston rod.

The gas flow output, however, depends on the speed of the chewing piston. Indeed, when the chewing piston rises, the membrane also rises and swells under the effect of the continuous gas supply (increase of the volume of the chamber from which a zero or very low gas output at the level of outlet orifice of the artificial mouth).

When the piston goes down again, the central part of the membrane also descends and deflates under the possible effect of the coaxial disc (reduction of the volume of the chamber which causes a massive gas outlet at the exit orifice of the mouth artificial).

It is therefore the combined movement of the piston driving the diaphragm and the continuous gas flow input which induces a sequential flow output, mimicking the breathing.

Thanks to such an artificial mouth, it is possible to obtain a "breathing rhythm" comparable to that of the human mouth. In this variant, this "inspiration-expiration rhythm" is dependent on the masticatory rhythm that can be varied between, for example, 10 and 60 mastications per minute.

Thanks to the joining of the flexible membrane to the piston rod, this first variant of the artificial mouth according to the invention also has the advantage of not requiring lubricants (which could contaminate or interfere with the volatile compounds of space head of the enclosure), since the moving parts are in no way in contact with each other.

According to a second variant of the invention, the central portion of the membrane and the coaxial disc are integral with a sleeve sliding along said piston, so as to disconnect the movement of the piston from that of the diaphragm, thereby disconnecting the "breathing rhythm" of the "chewing rhythm".

In this second variant, said membrane can also be inflated and lowered to the rhythm of the movements of the gaseous atmosphere of the enclosure during the trips back and forth of the upper plate in the volume of the enclosure. Consequently, thanks to this variable volume of this closed enclosure, there is no overpressure that can cause gas leakage from the enclosure.

Advantageously, the gas inlet communicates with a distribution chamber arranged below the lower plate, said lower plate being provided with perforations, in order to allow the diffusion of the gas flow through the food to be destructured disposed on said lower plate. .

It can be advantageously provided that the upper face of the lower plate has a rough surface to mimic the roughness of the tongue and facilitate "hook" food on the plateau, and therefore their destructuring.

Preferably, in addition to its vertical reciprocating movement of substantially constant amplitude, a progressive downward movement is printed on said piston, as a function of the stage of destructuring of the foodstuffs to be studied, in order to allow the progressive and complete destructuring of the latter. In addition, for a more complete study of the physicochemical phenomena involved during chewing, it can be provided that the artificial mouth is possibly equipped in the upper part of the enclosure of a device for introducing a salivary solution on food to be destructured, and a device for collecting / collecting saliva solution in the lower part.

In this case, the bottom of the chamber or the bottom of the gas distribution chamber may advantageously be of conical shape to facilitate the collection of said salivary solution.

The outlet orifice of the gas stream is advantageously connected to at least one device for collecting and / or analyzing the volatile compounds released during the destructuring of the foodstuffs.

This analysis device can be an olfaction cone. It is thus possible to install it on the level and in the extension of the gas exit orifice of the artificial mouth and that an individual can inspire and perceive the aroma of food during their destructuration in the artificial mouth, without being influenced by the color, texture, ... of said foods. This perception can be carried out continuously.

The "breathing rhythm" of the artificial mouth can be easily adjusted to the respiratory rate (usually around 15 to 20 breaths / minute per minute) of the individual placing his nose in the olfaction cone. A simultaneous chromatographic analysis device may also be placed at the outlet of this artificial mouth.

Such an artificial mouth thus makes it possible to reproduce the mastication conditions of a human mouth as well as possible, while making it possible to extract a larger number of volatile compounds from foods under the conditions closest to in vivo mastication, and to analyze simultaneously the flavors of said foods. The present invention also relates to a method for analyzing the compounds responsible for the sensory perception of solid food flavors, characterized in that the food is destructured in an artificial mouth as described above and traversed by a sequential gaseous flow directed to an olfaction cone and / or a chromatograph, where the volatile compounds released during the destructuring of said foods can be continuously collected and analyzed. These analyzes are qualitative, but can also be quantitative, they allow in particular to analyze liquid and / or gaseous fractions containing said compounds.

Preferably, the gas stream may be chosen from all the inert gases (Argon, Helium, Nitrogen), the air or its constituents, according to the associated analysis method (instrumental or sensory) and is advantageously air to reproduce the environment of chewing in vivo.

Other features and advantages of the invention will emerge from the following description of an embodiment given by way of non-limiting example and shown in the accompanying drawings, in which:

Figure 1 is a side view of an artificial mouth according to the present invention;

Figure 2 is a front view of the artificial mouth of Figure 1;

Figure 3 is a partial sectional view of the artificial mouth according to the present invention showing in more detail the enclosure used.

With reference to the figures, the artificial mouth according to the present invention comprises an enclosure 1 consisting of a double envelope formed of an inner wall 2 and an outer wall 3 made of stainless steel between which a fluid such as water circulates. for thermostating said chamber, for example, at a temperature of 37 ° C reproducing the temperature of the human body. The fluid enters through the inlet port A and exits through the outlet port B filling the entire space between the inner wall 2 and the outer wall 3.

Inside this chamber 1 are placed one above the other a lower plate 5 and an upper plate 4 substantially parallel between which are arranged the food 6 to be studied.

The lower plate 5 is connected to a drive shaft 7 coupled to a motor 8 shown schematically in Figures 1 and 2. Said motor 8 rests on a support 9 adjustable in height. This plate 5 is rotatable about the vertical axis 10. This rotation is preferably continuous, but a discontinuous rotation could be considered.

The upper plate 4 has on its underside facing the lower plate 5 rows of teeth 11, similar in shape to human or animal teeth, for destructuring and grinding food 6 when they come into contact with said food.

This upper plate 4 and the rod 12 which is associated with it constitute a piston moving vertically, actuated by a jack 13 mu by a motor 14. The assembly, as visible in the side view of FIG. 1, is held in place by the support assembly 15. This cylinder 13 can print to the upper plate 4 of the movements back and forth according to a predefined speed. These movements back and forth have a substantially constant amplitude but the motor 14 allows a progressive descent of said plate 4, namely depending on the height or thickness of food to destructure and the progress of their destructuring.

A gas flow F is fed into said enclosure 1 via an inlet 16 formed in the lower part of the enclosure and connected to a distribution chamber 17 formed under the lower plate 5. This distribution chamber may be, for example, circular or annular or conical shape (for a possible collection of liquid fraction that may include saliva). It is connected to perforations 18 formed axially through said plate 5, so as to pass the flow of gas F through said plate and bring it into contact with said food 6 to be studied. This gas stream may be a neutral gas or air, or one of its constituents (oxygen or nitrogen).

According to the present invention, the enclosure is closed in its upper part by a flexible membrane 19, for example Teflon, whose periphery is sealingly attached to the walls of the enclosure 1. Its central portion is here fixed to the rod 12 of the piston and sandwiched between an upper disk 20 and a washer 21 for fixing, themselves secured to the rod 12 of the piston.

Thus, according to a first variant of the invention shown in Figure 3, each vertical movement of the piston lowers or raises the membrane. The disk 20 is a stopper for swelling the membrane or lowering the membrane, to avoid excessive deformation that would damage it.

Figure 3 shows the extreme positions of the membrane:

in full line: the lower position of the upper plate 4 and the membrane 19,

in discontinuous lines: their high position.

A protective cover 23 may be provided above said membrane.

Finally, a gas outlet 22 provided on the periphery of the enclosure 1, preferably in the upper part of the enclosure in proximity to the membrane 19 makes it possible to collect the gas flow from the head space of the enclosure, and thus to collect the volatile compounds resulting from the destructuring of the crushed foods in said enclosure.

This outlet 22 can be connected to a corona collection system or a chromatographic system, but also to an olfaction cone 24 so that an individual can perceive the aroma of said foods 6 during their mastication in the artificial mouth according to the present invention. The coupling of this artificial mouth, an instrumental process, to a human nose has the advantage of overcoming the inter-individual variability in terms of all the factors involved in the tasting of a food (oral physiology). , frequency of chewing, composition of saliva, respiratory rate ...). The physicochemical changes of the food that take place during chewing are thus controllable, which facilitates their understanding. The mixture of odoriferous volatile compounds reaching the olfactory receptors of the individuals leaving the artificial mouth can therefore be identical for each of the individuals placed at the outlet. The process coupling artificial mouth-individual then allows to dissociate:

-the human cognitive factors resulting from the perception of volatile compounds,

-physicochemical factors that occur in the food placed in the mouth and affect the release of volatile compounds it contains.

Claims

1. Artificial mouth for the study of the phenomena involved in the mastication of foodstuffs, in particular the study of food histories, in particular solid foods, comprising an enclosure (1), preferably with thermally closed walls, closed hermetically by a lid, in which are arranged two substantially parallel plates, animated relative movements one pa rraport to the other, able to reproduce masticatory movements of destructuring food (6) arranged between them on the one hand a lower plate (5) intended to support said foodstuffs to be studied, and on the other hand an upper plate (4) disposed above the lower plate (5) and whose face opposite the lower plate is equipped with a plurality of rows of teeth (11), said upper plate (4) and the rod (12) to which it is secured constituting a piston driven by a vertical reciprocating movement, and said plate in bottom (5) animated with a rotary movement able to mimic the repositioning of food by the tongue under the teeth, said enclosure (1) being further equipped with a gas inlet (16) and an outlet port of gas (22) formed in or near the lid, a gas flow being capable of driving the volatile compounds, released during the destructuring of food between the two trays, towards said outlet orifice, in order to allow the analysis of the output said volatile compounds, responsible for the aroma of said foods, characterized in that the lid consists of a flexible membrane (19), whose periphery is sealed to the walls of the enclosure, and whose central part is alternately raises and lowers as a function of the movements of the upper plate (4) or as a function of the gaseous flow leading to sequential variations in the volume of the chamber (1), mimicking the breathing and the alternating swelling of the cheeks during chewing.

2. Artificial mouth according to claim 1, characterized in that a disc (20) coaxial carried by the rod (12) of said piston, upper stopper shape of the membrane (19) during its swelling, and optionally serves as a means training / or accompanying said membrane during its lowering.

3. Artificial mouth according to claim 2, characterized in that the central portion of the membrane (19) and the disk (20) coaxial are integral with the rod (12) of the piston.

4. Artificial mouth according to claim 2, characterized in that the central portion of the membrane (19) and the disk (20) coaxial are integral with a sleeve sliding along the piston rod.

5. Artificial mouth according to any one of the preceding claims, characterized in that the surface of the lower plate (5) is rough.

6. Artificial mouth according to any one of the preceding claims, characterized in that the gas inlet (16) communicates with a distribution chamber (17) formed below the lower plate (5), said lower plate being provided perforations (18), in order to allow the diffusion of the gas stream through the food to destructure disposed on said lower plate (5).

7. Artificial mouth according to any one of the preceding claims, characterized in that, in addition to its vertical reciprocating movement of substantially constant amplitude, a progressive downward movement is printed to said piston, depending on the stage of destructuring of food to to study, in order to allow the progressive and complete destructuring of the latter.

8. Artificial mouth according to any one of the preceding claims, characterized in that it is equipped in the upper part of the chamber (1), a device for introducing a salivary solution on food to destructure , and possibly a salivary solution collection / sampling device at the bottom.

9. Artificial mouth according to any one of the preceding claims, characterized in that the outlet orifice (22) of the gas stream is connected to at least one device for collecting and / or analyzing the volatile compounds released during the destructuring of food.

10. Artificial mouth according to claim 9, characterized in that the analysis device is an olfaction cone (24).

11. A method for analyzing the compounds at the origin of sensory perception, especially flavorings, of solid foods, characterized in that the food is destructured in an artificial mouth according to any one of the preceding claims and traversed by a sequential gas flow directed towards an olfaction cone or a chromatograph, where the volatile compounds released during the destructuring of said foods can be collected and analyzed continuously.