MXPA97003376A - Method of elimination of notes of bad flavor in ca products - Google Patents

Abstract

A method for treating fermented cocoa beans to produce peeled, roasted, reduced-acid cocoa, which has a reduced level of 2-methoxy-3-isopropyl-pyrazine (MIPP). The method involves treating cocoa beans with steam at a temperature in the range of about 100 ° C to about 140 ° C for a period of time from about 10 minutes to about 120 minutes.

Description

METHOD OF ELIMINATING NOTES OF BAD FLAVOR IN COCOA PRODUCTS INDUSTRIAL FIELD This invention relates to a method of converting fermented cocoa beans into a cocoa mass. It also refers to the use of a method intended to achieve specific results, which include the elimination of notes of bad taste of the grains, thus opening the possibility of making a good quality chocolate from grains that have a note of Bad taste. The invention also relates to the cocoa mass obtainable by the process of the invention and the chocolate made from this cocoa mass or by the method of the invention.

BACKGROUND IN THE TECHNIQUE US Pat. No. 2558854 describes the production of chocolate from a cocoa pod, which is the fruit of Theobroma cacoa. A premium chocolate should be lacking in that bad taste that has been described in various ways such as moldy flavor, musty taste or earthy flavor. Therefore, chocolate manufacturers can not use grains that can be responsible for this type of flavor in the manufacture of a chocolate of superior quality. They therefore require only higher quality grains. Specifically, consensus has been reached that grain feed materials that have a moldy grain content of more than 3% are unacceptable. The mold of the grains can be internal, external, or of both types. There is a research paper published in 1987 (Baigrie et al., Flavor Science and Technology, 1987, pages 133-141) which indicates that many food materials with a high level of mold do not produce, however, a chocolate with a taste moldy. It remains unclear with this, what are the appropriate grains to make a chocolate of superior quality and which are not. In this 1987 paper, Baigrie has identified 2-methoxy-3-isopropylpyrazine, MIPP, as the major contributor to bad taste, designated as moldy flavor / musty taste or earthy flavor / musty taste by flavor specialists. In this work, it is further assured that the bad taste in low quality cocoa beans may in fact have nothing to do with the actual presence or absence of molds inside or outside the grains. Baigrie has found that 2-methoxy-3-isopropylpyrazine (MIPP) suppresses chocolate flavor but that this effect is not limited to MIPP and that flavor suppression mechanisms "are clearly complex".

It is already known that the bad tastes of cocoa beans can be eliminated by superheated steam. See, for example, US-A-4861615, according to which fragments of raw material cocoa beans are then introduced into a screw extruder, which are then subjected to the action of high pressure steam before mixing, kneading and degassing them. . In a third zone of the extruder the roasting is carried out using heat that is supplied through the wall of the extruder housing. The patent US-A-2278483 (published on April 7, 1942) shows that the husks of the cocoa beans can be detached by subjecting the husks to steam action to a substantial overheat and high pressure. It is recommended a pressure as high as practicable, with a sudden elimination of this pressure, which has an explosive effect on the grains, for a better separation of the almonds from the husks. An effect on flavor development is noted, if the treatment is continued for longer than that required for husking, but it is explained that this development of flavor is achieved in any way during the subsequent processing of the almonds. The reading device is placed so that it selects the highest possible pressure, in order to make the treatment time as short as possible, for economic reasons. Treatment times of 5 to 50 seconds and 5 to 120 seconds are specified. Patent DD 98817 describes the addition of water to the cocoa mass and subsequent heating of the dough, in order that the subsequent evaporation of water improves the flavor of the cocoa by favoring the efflux of constituents that deteriorate the flavor. Patent SU-A-1324626 describes an apparatus for hydrothermal treatment of cocoa beans, but nothing is said in the document about the details of the process conditions. Patent EP-A-0061229 describes the treatment of a wide range of materials including grains of cereals and cocoa beans with heat and pressure. It should be noted that it is customary to improve the organoleptic characteristics (taste, appearance, smell) of cereals by these techniques. Temperatures of at least 200 ° C are recommended, together with high pressures, preferably in the range of 5-35 atmospheres, for periods of time such as 3-13 seconds. With this treatment more than 99.9% of bacteria were killed in two samples of cocoa beans. Patent EP-A-0068221 proposes the treatment of cocoa beans in their husks by first moistening and heat treating at temperatures of at least 150 ° C. This facilitates the subsequent separation of the cocoa beans from the husks, and kills the bacteria in the feed material. The cocoa almonds are then toasted. US-A-4970090 discloses methods for improving and intensifying the taste of aqueous or ethanolic cocoa extract by maintaining it at a high temperature, of more than 125 ° C but less than 150 ° C, for periods of time from 3.5 to 4. ,5 hours.

In the current state of the art there are many descriptions of the use of steam in processes for the reduction of the bacterial content of raw material cocoa beans. DE-A-3902679 provides a review of the technique and this same patent suggests the use of saturated steam at 0.6 Mpa (6 bar) and 160 ° C for this purpose. An object of the present invention is to provide an economical method of making chocolate from cocoa beans that maximizes the chocolate flavor and suppresses the negative flavor notes. It is another object of the invention to produce chocolate products of a given quality from cocoa grain feedstocks that would otherwise be considered of inadequate quality.

DESCRIPTION OF THE INVENTION This object is achieved with a method of converting cocoa beans fermented into a cocoa mass, by the step of contacting the beans with an incident steam flow, which is provided at a temperature that is in the range from about 100 ° C to about 140 ° C. Preferably, the grains are steam treated while still in their husks. This facilitates the subsequent separation of the grains from the husks. Preferably, the steam treatment replaces the conventional roasting treatment. In this way, the grains are dehusked and roasted in a single stage. It is preferred to effect the steam treatment using saturated or substantially saturated steam (as in a classical steam distillation process). In this way, the grains receive enough steam and heat to "roast" the grains. No more roasting of the beans is necessary before tasting them. This is a valuable result of the present invention. The treatment temperature is in the range of 100 to 140 ° C, more preferably 100 to 130 ° C and most preferably 100 to 110 ° C. As for the pressure with saturated steam, this would be fixed by the temperature of the steam. In any case, a pressure of 50 to 300 Kpa (0.5 to 3.0 bar) is preferred.

Higher pressures may increase the likelihood of the loss of desirable flavor notes and the generation of negative flavor notes. It has been found that a vapor to grain ratio in the range of 0.1-1.0 / 1.0 gives good results, which means obtaining adequate but not excessive roasting. A preferred point in the range is a steam to grain ratio of 0.4 to 1. The ratio refers to that between the weight of the steam absorbed by the grains plus the condensate and the weight of the grains presented for treatment with steam. A steam treatment time of 10 to 120 minutes is indicated, in accordance with the above limitations, to achieve a suitable but not excessive steam treatment. Preferred steam treatment times vary between about 15 and about 30 minutes. Although the main advantage of the invention is that the steam treatment facilitates the achievement of the separation of the husks of the cocoa beans by "roasting" the beans at the same time, there are nevertheless clear advantages in terms of elimination of the notes of bad taste by previously submitting the cocoa almonds with their peel to the steam treatment process of the invention.

In short, it is considered that the steam treatment process substantially reduces the 2-methoxy-3-isopropylpyrazine (MIPP) content of the grains to a smaller amount, while leaving the pyzine content of positive taste note. In this way, the notes of bad taste are reduced, but the notes of desirable flavor remain. The invention offers, therefore, the opportunity to obtain a chocolate of superior quality from grains of medium quality which is a commercial advantage of the greatest importance. The authors of the present invention have studied the relationship between bad tastes, steam treatments and MIPP content, in grains from different countries and from different sources. In short, with grains of a more acid taste, such as those typical of Malaysia, Papua New Guinea and Indonesia, a panel of flavor experts is unable to detect a bad taste of mold in the taste of the beans if the MIPP content is below 3 μg / Kg. For less acidic grain feedstocks, such as those from Côte d'Ivoire, the MIPP content above about 1.0 μg / Kg is susceptible to being detected by a panel of flavor experts as a bad taste of mold. As a result, it is concluded that it would be desirable to subject the grains to steam treatment to reduce the MIPP levels to a value below the above-mentioned levels. Because the loss of desirable pyramid flavor notes may be limited to acceptably low levels, the steam treatment process of the present invention may be an acceptable way to effect only the shedding of the kernels. The specifications of the steam treatment process can therefore be established regardless of whether the beans are moldy or not, in the confidence that this need does not result in a loss of the flavor of the beans without deterioration due to negative taste precursors. By making the process conditions too energetic, however, burnt notes can be introduced into the flavor. Although in some markets this may be desirable, it usually has to be avoided by limiting the severity of the process conditions. For a better understanding of the invention, and to show more clearly the way to carry it out in practice, reference is now made, by way of example, to the accompanying drawings, in which: Figure 1 is a schematic diagram of an apparatus for treating cocoa beans with steam. Figure 2 is a block diagram of a pilot plant for steam treatment of cocoa beans; and Figure 3 is a longitudinal diametrical section of a steam treatment vessel of a commercial facility for steam treating cocoa beans. The apparatus shown in Figure 1 comprises a container 10 in which the item 11 of cocoa beans to be treated can be loaded. The vessel 10 has a cover 12 in which oil 13 can be circulated in order to maintain the interior of the vessel 10 at the desired treatment temperature. The saturated steam 14 is introduced through the base of the treatment vessel 10. The vapor 14 comes from a water source 15, upstream of a steam generator 16 which produces saturated steam at the flow rates required by the process. The vapor flow through the vessel exits through the upper part of the vessel, through a pressure control valve 17. There is a pressure controller 18 that is programmed with the desired pressure profile for the steam treatment process. This receives from the pressure sensor 19 an indication of the instantaneous pressure of the vapor inside the container 10, and controls the valve 17 according to the indicated pressure, in order to maintain the desired pressure profile.

Downstream of the valve 17 there is a condenser 20 and a vacuum pump 21 which is used to set the desired vapor pressure inside the condenser 20. The condensate 22 is further treated in a tape condenser (not shown). In the operation, the fermented raw material cocoa beans are loaded with their husks into the vessel 10, and brought to the preselected steam treatment temperature, using the oil cover 12 of the container to maintain the beans at the temperature of treatment. The grains are then treated with steam, using saturated steam at the pressure of the pre-selected steam treatment, which in turn fixes the temperature of the saturated steam. After treating with steam during the pre-selected treatment time, the flow of saturated steam is interrupted, and the steam-treated grains are removed from the treatment chamber, for further processing. During the treatment, the steam flow can be adjusted through the container, in order to achieve, at the end of the steam treatment, the steam-to-grain ratio pre-selected. Returning to Figure 2, the pilot plant 40 is centered on a steam treatment vessel 41 with a capacity of 20 liters and which is surrounded by the heating mantle 42. The grains to be steam treated are loaded into the vessel through conduit 43 from a hopper 44 under the control of a gas-tight ball valve 45. A process water reservoir 46 of 50 liters capacity is mounted on a balance 47 operated by a flow controller 48 for feeding a piston pump 49 through a flexible hose 50. The pump 49 and the flow controller 48 are both under the control of a process controller 51. From the pump 49, water is supplied to a pre-heater 52, in which a temperature controller 53 sets the desired temperature in the water. A non-return valve 54 in the line 55 downstream of the pre-heater maintains the desired pressure in the pre-heater, indicated in a pressure indicator 56. In this way, the water enters a pre-selected temperature and pressure. in the steam production vessel 58 to produce steam at a temperature controlled by the temperature controller 57. The steam pressure in the process vessel 41 is controlled by a main pressure valve 60, controlled in turn by the drive device pressure control 61, and there is also a fine adjustment steam pressure valve 62. Immediately downstream of the process vessel 41 there is a pressure indicator 63. Downstream of the main pressure valve 60, the steam condenses in a condenser 64 carrying cooling water 65.

The product to be treated with steam is also heated in the process vessel by steam flow through the sleeve 42, which is provided for this with a steam flow control valve 66, pressure controller 67 and trap for steam 68. The process vessel 41 has a discharge outlet in the bottom which is controlled by a pneumatically driven ball valve. The steam treated product is discharged past this valve on a screen 70 having a mesh opening of 3 mm, below which is the tank 71 for receiving the water draining from the steam treated product through the screen. In use, the walls of the process vessel 41 are heated by flowing steam through the sleeve 42. Typically, the walls are maintained at a temperature of 150 ° C. A first game of successive games of 5 is loaded Kg of cocoa beans through the ball valve 45 from the hopper 44 in the process vessel 41. With both ball valves 45, 69 sealed, a measured amount of process water is pumped from the tank 46 through from the pre-heater 52 to the steam generator 56 and the resulting steam is made to flow through the grain charge in the process vessel 41. When the specified amount of steam has been made to flow (in relation to the grain mass of the vessel 41) through the loading of grains, at the pre-selected temperature and pressure, and has been absorbed by the grains, the operation of the pump 49 is interrupted, and the load of steam-treated grains is allowed to flow out of the container 41 by opening the valve 69. It can be loaded then the grain item in the process vessel. Those parts of the installation that come into contact with the product flow are made of stainless steel. Figure 3 shows a larger steam treatment vessel, intended for commercial use, with a capacity of 125 kg of grains to be treated with steam in each successive loading of the container. The container 110 has a conical base 112, a height just above 4 m and an inside diameter of 0.8 m. Its stainless steel walls 114 are stable at an internal overpressure of the container of 1 MPa (10 bar) and are thermo-insulated on the outside with a coating 116 of 10 cm thick of Rockwool®. The open top 118 of the container is closed with a large flat cover 120 which can be lifted and moved to one side to load the container. The 10 cm gap 121 between the container 110 and its cover 120 when in place is an escape route for the treatment steam of the container grains. At the apex 122 of the conical base 112 of the container there is an outlet opening 124 controlled by an outlet ball valve 126. Just above this apex there is also a steam inlet dispenser 128 in the form of a stainless steel ball 10 cm in diameter with a multitude of small holes on its surface, which supplies steam 130 at a maximum speed that can be of the order of 220 kg / hour, typically at a pressure of 0.2 Mpa (2 bar) and a temperature of 120 ° C. Typically, the actual temperature within the grains 132 at the end of the steam treatment is in the range of 103 ± 2 ° C. When using it, the container is preheated, passing a steam current through it, until the steel walls reach a temperature of 100 ° C. 125 kg of cocoa beans are then manually loaded into the container and the steam treatment is then started at a flow rate of 200 kg of steam per hour. After about 3 minutes, steam begins to emerge from the top of the container. After a total time of 15 minutes of steam treatment, the temperature of the grains is in the range of 101 to 105 ° C. The grains are discharged from the base of the container into tanks for transport to a desiccator. The beneficial effects of the steam treatment process are evident in the following examples.

EXAMPLE 1 5 kg of raw material cocoa beans were treated (Ivory Coast) with a note of bad taste to mold in a pressure vessel for 15 minutes with saturated steam at a temperature of 105 ° C. The ratio of steam to grains was 0.8. After the treatment it was very easy to separate the husks. The note of bad taste had been completely lost, in the sense that it could not be detected by the group of flavor experts. The MIPP content was reduced as follows: MIPP content Raw cocoa steam 3.5 μg / kg Steamed cocoa 0.5 μg / kg MIPP reduction 3.0 μg / kg (= 86%) EXAMPLE 2 The treatment of Example 1 was repeated, with a 5 kg sample different from a Côte d'Ivoire cocoa. Again there was a loss of the bad taste note and the MIPP content was reduced, as follows: Content in MIPP Uncoated cocoa with steam 2.8 μg / kg Steamed cocoa 0.2 μg / kg Reduction of MIPP 2, 6 μg / kg (= 93%) EXAMPLE 3 5 kg of raw material cocoa beans (Côte d'Ivoire) that had a bad taste to mold in a pressure vessel for 30 minutes were treated with saturated steam at a temperature of 105 ° C. The vapor to grain ratio was 0.4. The separation of the husks was very easy after the treatment. The bad taste note was completely lost, in the sense that it could not be detected by the group of flavor experts. The content of MIPP was reduced as follows: Content in MIPP Cocoa untreated with steam 3.8 μg / kg Cocoa treated with steam 0.6 μg / kg Reduction of MIPP 3.2 μg / kg (= 84%) Increase in pH: from 5, 69 to 5.97 Note: pH differences can be appreciated organoleptically 0 +/- 0.05. EXAMPLE 4 5 kg of cocoa beans from raw material (Ivory Coast) were treated with a bad taste to mold in a pressure vessel for 30 minutes with saturated steam at a temperature of 105 ° C. The vapor to grain ratio was 0.8. The separation of the husks was very easy after the treatment. The bad taste notes had been completely lost, in the sense that it could be detected by the group of flavor experts. Content in MIPP Uncoated cocoa with steam 2.8 μg / kg Steamed cocoa 0.4 μg / kg Reduction of MIPP 2.4 μg / kg (= 86%) Increase in pH: from 5, 65 to 5, 99 EXAMPLE 5 A 5 kg sample of cocoa beans from Ivory Coast raw material having a moldy taste in a pressure vessel was treated for 15 minutes with saturated steam at 105 ° C. The vapor to grain ratio was 0.4. After the treatment, the panel of flavor experts was unable to detect the bad taste note. Gas chromatography-mass spectrum analysis (GC-MS) indicated a 95% reduction in MIPP content. The pH measurement indicated an increase from 5.61 to 5.94. It was found that the treatment had produced a less bitter, milder flavor in the beans. During the treatment the grains lost their husks. EXAMPLE 6 The product of Example 5 was subjected to comparative taste and odor testing with respect to a product of conventionally roasted cocoa beans, made from fermented cocoa grain feedstock devoid of off-flavors notes. The panel of experts was unable to distinguish the conventional product, made with "good" grains, from the product of Example 5 made from grains of "inferior" quality. EXAMPLE 7 4.5 kg of cocoa almonds from Malaysia were treated with 3.3 kg of saturated steam at 100 ° C for 110 minutes. 84% of the volatile acidity was removed, thus increasing the pH from 5.0 to 5.3. The grains thus treated had a smoother flavor, more nutty flavor, more pleasant and less sour. EXAMPLE 8 4.5 kg of cocoa almonds from Malaysia were treated with 4.5 kg of saturated steam at 100 ° C for 110 minutes. 85% of the volatile acidity was removed, increasing the pH from 5.0 to 5.4. The treated beans had a considerably milder flavor, more nutty flavor, more pleasant and less sour. EXAMPLE 9 2000 Kg of Côte d'Ivoire cocoa beans from raw material, which had a bad taste to moldy flavor, were treated in a pressure vessel for 15 minutes with saturated steam at 105 ° C and a vapor ratio of 0.4 grains. After the steam treatment, the separation of the husks was very easy. The group of flavor experts was able to confirm the elimination of the bad taste note. The results were as follows: Increase in pH: from 5.65 to 6.12 MIPP reduction: 86%, from 3.5 μg / kg to 0.5 μg / kgEXAMPLE 10 Grains of Côte d'Ivoire raw material, of 5 kg each, which had a bad taste to moldy flavor, were treated with saturated steam during a period of 15 to 30 minutes at a ratio of steam to grains of 0.4 Three different treatment temperatures were employed to explore the effect of changing the temperature of the steam treatment on the taste. The results were:

Claims (15)

CLAIMS 1. A method for the treatment of cocoa beans to produce peeled, roasted cocoa, which is characterized by the step of: contacting the cocoa beans with steam at a temperature in the range of about 100 ° C to about 140 ° C. ° C for a period of time from about 10 minutes to about 120 minutes to produce reduced-acid roasted cocoa having a lower level of 2-methoxy-3-isopropylpyrazine (MIPP). 2. A method according to claim 1 wherein the temperature is from about 100 ° C to about 130 ° C. 3. A method according to claim 2 wherein the temperature is from about 100 ° C to about 110 ° C. 4. A method according to any of the preceding claims wherein the vapor is substantially saturated vapor. 5. A method according to claim 1 wherein the period is from about 15 to about 30 minutes. 6. A method according to any of the preceding claims wherein the ratio of vapor weight absorbed by the grains to weight of grains presented to the steam treatment is in the range of about 0.1 to about 1.0 / 1.0. . 7. A method according to claim 6 wherein the vapor to grain ratio is equal to, or approximately equal to, 0.4 / 1.0. 8. Use according to claim 1 in which the grains come from Ivory Coast and the method limits the content of MIPP in the whole of the grains to less than about

1.0 μg / Kg. 9. Use according to claim 1 wherein the grains come from Malaysia, Papua New Guinea or Indonesia and the method limits the MIPP content in the whole grains to less than about 3.0 μg / kg. The method according to claim 1 further comprising the step of making confectionery chocolate from the steam-treated cocoa beans. 11. Cocoa mass, which can be obtained from fermented cocoa beans by a method comprising the step of contacting the beans with an incident steam flow having a temperature that is in the range of about 100 to about 140 ° C. 1

2. Cocoa mass according to claim 11, made from grains having a note of bad taste to mold. 1

3. Cocoa mass according to claim 11 or claim 12, made from grains originating from Ivory Coast, the mass having a MIPP content of less than about 1.0 μg / Kg. 1

4. Cocoa mass according to claim 11 or claim 12, made from grains originating in Malaysia, Papua New Guinea or Indonesia, the mass having a MIPP content of less than about 3.0 μg / Kg. 1

5. Chocolate made from cocoa mass according to any of claims 11 to 14.