MXPA00004413A - Process for removing micotoxins from a load of green coffee - Google Patents

Abstract

Green coffee is introduced into a container where it is subjected to continuous mixing in temperature conditions ranging between environment and values close to 120°C and water vapour is introduced into said container until the single beans of coffee have become porous and permeable;micotoxins are removed by extraction with a solvent in an acid environment obtained with a given acid or with a buffer solution with a given acid pH.

Description

PROCESS TO REMOVE MYCOTOXINS FROM A LOAD OF FRESH COFFEE DESCRIPTION OF THE INVENTION The present invention relates to a process for removing mycotoxins from a fresh or harvested coffee load, in this case considering mycotoxins as at least those mycotoxins known as ochratoxins and aflatoxins that may be present in fresh coffee. One of the purposes of this process is to remove the mycotoxins by maintaining the amount of caffeine within the values of a non-decaffeinated coffee. It is well known that the amounts of these mycotoxins in coffee are very small in an absolute sense (for example, of only a few ppb (parts per million, this is mg / ton) and that their presence may depend on the geographical area in which coffee grows, in the possible conditions of an unfavorable climate and / or possible negligence in storage and handling On May 13, 1996, the applicant sent the patent application MI 96 A 000960 for an adequate industrial process to remove the mycotoxins mentioned before fresh coffee, the process essentially comprises the following steps: a) introducing a fresh coffee load containing mycotoxins into a container in which the coffee will preferably be subjected to continuous mixing at temperatures that mj &Xiñij "* '? r, > t - vary between ambient temperature and values of approximately 105 ° C; b) introduce water vapor into the container where it is held until the coffee beans become porous and permeable, c) introduce a suitable solvent into the container to remove waxes and mycotoxins and extract the solvent as soon as the waxes and most of the coffee mycotoxins have been removed, d) recover the solvent and separate the latter from Mycotoxins contained therein A first alternative to stage c) above is the stage: c ') to introduce a solvent saturated with caffeine into the container and leave it for a sufficient time to remove all of the mycotoxins. the process contemplates the repetition of stage c) in order to increase the level of mycotoxin removal A first drawback of the previous process is in the difficulty, from a point from a plant view, to operate with a solvent saturated with caffeine. A second drawback is, given the fact that the solvent is saturated with caffeine, large quantities of caffeine are required.

A further drawback of such a process is generated by the fact that the repetition of step c) in order to increase the removal of mycotoxins at a higher level. causes the removal of additional amounts of caffeine from coffee The applicant has carried out additional experiments until it is found that, by means of a certain acid environment obtained by means of a chosen acid or a buffer solution with a given acidic pH, in some of the process steps, the removal of mycotoxins is increased, and at the same time. time is reduced caffeine removal in relation to known processes. Note that the known processes are carried out in a neutral environment. The acidic environment suitable for the above results is chosen by the operator between pH = 7 and pH = 2 as a function of the contact time between the coffee and the acid mixed with the solvent used or also contact time between the coffee and the coffee. buffer solution as a function of the temperature at which the contact takes place. Such an acidic environment can be obtained as follows: 20 - introduce in the process an acid mixed with the solvent for the removal of mycotoxins, or as an alternative; introduce a buffer solution with an acid pH into the process and leave it in contact with the coffee for the required time, - ^ lfgj ^^^^^^^^ j ^^^^^^ g ^^^^ Then download the buffer solution and introduce the solvent for the removal of the mycotoxins. Based on the results of the additional experiments, the process which is the object of the present patent application comprises the following known steps: a) introducing a fresh coffee load containing mycotoxins into a container in which the coffee is preferably subjected a continuous mixing under temperature conditions that vary between the environment and values of approximately 105 ° C; b) introducing steam into the container to keep it there for the time required for the coffee beans to become porous and permeable; and again includes, as characterized in the claims, the following subsequent steps: c) introducing within the container an amount of solvent equal to at least 50% of the weight of the coffee, the solvent contains an adequate amount of acid, and leaves it in contact with the coffee for at least 10 min at temperatures ranging from the environment to approximately 105 ° C, such higher value increases up to 120 ° C when using solvent classes adapted for this, - this step c) can be Repeat until most of the mycotoxins have been removed. Note that a "Adequate amount of acid" means that quantity, chosen by the operator depending on the contact time between the coffee •*H.H . a * z * & ^ ae? ^ ^. ^ ^ tlJÉÍÍMMÍ? 8ft¡iií1 ??? 1? i? ilel? Ii ^^ and the acid mixed with the solvent and based on the temperature at which the removal takes place, - d) recovery of the mycotoxin removal material and separation of the mycotoxins contained in it. An alternative to step (c) above, is a step: c ') introducing a buffer solution that generates a chosen acid pH, acidity is a function of the contact time of the same buffer with coffee and as a function of the temperature at which this stage of the process takes place, the buffer solution is a variable amount between 50 and 200% of the weight of the coffee load; the contact time varies between 10 and 60 minutes, - d ') discharging the buffer solution; e) introducing in the container an amount of solvent, equal to at least 50% of the weight of the coffee charge, and then extracting it after the removal of most of the coffee mycotoxins; f) recover the mycotoxin removal solvent and separate the mycotoxins contained therein. A further improvement defined by the experiments is to add to the water vapor in step (b) an amount of water varying between 5 and 50% by weight of the coffee charge at a temperature that varies between the environment and a value close to 90 ° C so that the coffee beans become porous and permeable more quickly. In order to better understand the invention, some examples of the mode of the process are described below.

EXAMPLE 1 Description of a process in which the removal step takes place at room temperature and the acid is previously mixed with the solvent: a) as defined above; b) as defined above; c) introducing into the container an amount of dichloromethane equal to at least 50% of the weight of the coffee charge, the dichloromethane contains 2% formic acid and leaving it in contact with the coffee for 30 minutes, this step is repeatable until have removed most of the mycotoxins. d) Recover the mycotoxin removal material and separate the mycotoxins contained in it.

EXAMPLE 2 Description of a process in which a vessel that is brought to temperature is previously filled with an acid pH buffer: a) as defined above; I love you;... b) as defined above; c) introducing into the container an amount of phosphate buffer solution with pH 4, which varies between 50 and 200% by weight of the coffee charge, and leaving it in contact with the coffee for 15 min. d) Download the buffer solution; e) Introduce in the container dichloromethane, in an amount equal to at least 50% of the weight of the coffee charge in order to remove the mycotoxins and extract the solvent after the removal of most of the coffee mycotoxins; f) Recover the solvent and separate the mycotoxins contained in it.

Claims (5)

1. A suitable process to remove mycotoxins from a load of fresh or freshly harvested coffee, with a solvent, in which coffee is introduced into a container where it is subjected to continuous mixing under temperature conditions ranging from room temperature to a value about 105 ° C, and steam is introduced into the container until each of the coffee beans becomes porous and permeable, the process is characterized in that it takes place in an acid environment obtained by means of a chosen acid or a acid buffer solution at a temperature that varies between room temperature and 120 ° C.

2. The process as described in claim 1, characterized in that the acidic environment will be chosen between pH = 7 and pH = 2 as a function of the contact time between the coffee and the chosen acid mixed with the solvent or the contact time between the coffee and the buffer solution chosen as a function of the temperature at which the contact takes place.

3. The process as described in claims 1 and 2, characterized in that it includes the following steps: to introduce in the container an amount of solvent equal to at least 50% of the weight of the coffee charge, the solvent contains a suitable amount of acid , and leave it in contact with the coffee for a time of at least 10 min, such a step is repeatable until most of the mycotoxins are removed; recover the mycotoxin removal material and separate the mycotoxins contained in it.

4. The process as described in claims 1 and 2, characterized in that it includes the following steps: introduce a quantity of acid buffer solution at the chosen level of acidity varying between 5 and 200% of the weight of the coffee charge, and leave it in contact with the coffee during a time that varies between 10 min and 60 min; unload the buffer solution; introduce in the container an amount of solvent equal to at least 50% of the weight of the coffee charge and extract it after the removal of most of the coffee mycotoxins; recover the mycotoxin removal solvent and separate the mycotoxins contained in it. -? "-

5. The process" * as described in the previous claims, characterized in that in the step of introducing water vapor into the container, an amount of water varying between 5 and 50% of the charge of water can be added. coffee steamed water, at a temperature that is between room temperature and a value close to 90 ° C. 'faith * »- *' ^ ^^^^ ^^^^^^^. ^^^^