Method for producing clarified oil from coffee grounds and from whole and/or damaged beans

Abstract

A method designed to clarify the coffee oil contained in coffee grounds or in whole and/or damaged coffee beans. The method objective is achieved by starting with inoculation of the coffee grounds or coffee beans with macromycetes especially with white rot fungi, continuing with an incubation, step that allows complete population of the coffee grounds or coffee beans by the fungal mycelium to be achieved, and finishing with steps of drying and extracting the coffee oil. The method disclosed allows colourless or pale yellow coffee oil to be produced, favouring the use thereof in cosmetic and food products, amongst others.

Claims

1. A process for obtaining clarified oil from spent roasted coffee grounds and whole and/or deteriorated roasted coffee beans, wherein the process comprises the following steps: a) inoculation of spent roasted coffee grounds and/or whole and/or deteriorated roasted coffee beans with macromycetes comprising white rot fungi having mycelium to form a mixture; b) incubation of the mixture until it is completely populated by the mycelium to form an incubated mixture; c) drying the incubated mixture; and d) solvent extraction of coffee oil from the dried incubated mixture.

2. The process of claim 1, wherein the white rot fungi are selected from Pleurotus spp., Corolius versicolor and Lentinula edodes, or mixtures thereof.

3. The process of claim 1, wherein the spent roasted coffee grounds and/or the whole and/or deteriorated coffee beans comprise between 1% and 10% by wet weight of the mixture.

4. The process of claim 1, wherein the duration of the incubation step is between 10 and 45 days.

5. The process of claim 1, wherein the drying step is performed at a temperature of between 35° C. and 55° C. for a duration of 24 hours.

6. The process of claim 1, wherein the solvent extraction step is performed with a solvent selected from hexane, ethyl acetate or mixtures thereof.

7. The process of claim 1, wherein the spent roasted coffee grounds, undergo thermal treatment by heating prior to inoculation.

8. The process of claim 1, wherein the whole and/or deteriorated coffee beans are washed with water to remove any impurities and thereafter warmed to decrease humidity prior to inoculation.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a flow chart of the process revealed here, showing the different stages involved and the main laboratory conditions used;

(2) FIG. 2 is a photograph that allows appreciating a sample of spent coffee grounds inoculated with macromycetes and completely populated, the previous, in accordance with the process here revealed;

(3) FIG. 3 is a photograph in which the appearance of the previously inoculated and populated spent coffee grounds is observed, and after being subjected to a drying process;

(4) FIG. 4 is a series of photographs that allow us to appreciate: 1) The coffee oil commonly extracted, which is characterized by being dark brown (left); and 2) The clarified coffee oil according to the process disclosed in this invention (right).

DETAILED DESCRIPTION OF THE INVENTION

(5) In addition to what was previously stated, the object of the this application can be appreciated in detail by the subsequent description of the stages of the process developed:

(6) The first stage of the process is to carry out the inoculation of the raw material (spent coffee grounds or coffee beans) with macromycetes. Such step involves mixing the raw material with the fungus in such a way that the first one represents between 1% and 10% in wet weight of the mixture, preferably between 2% and 5%.

(7) In a particular realization of the invention, such first stage can be preceded by previous thermal treatments and/or by washing procedures of the raw material. In the case of the spent coffee grounds, the heating of the dough is relevant when it is not fresh, that is, when more than 24 hours have passed since the extraction of the coffee beverage and the respective spent coffee waste has been generated, since the exposure to the environment for more than 24 hours causes the spent coffee waste to fill with fungal spores capable of colonizing the medium very quickly.

(8) On the other hand, when coffee beans are used as raw material, in certain cases it will be advantageous to carry out previous washings with water to remove any impurities from the surface, including fungi that may be growing there, as well as eventually warming the beans to decrease their humidity.

(9) The inoculation can be done with any macromiceate. However, in a preferred model of the invention, the inoculation is carried out with a macromiceate selected from: Pleurotus spp., Corolius versicolor, Lentinula edodes and mixtures thereof. Micromycetes can also be used, in which case a higher percentage of moisture in the raw material may be required.

(10) The process can be carried out using spent coffee grounds or coffee beans from any variety.

(11) The next step consists in the incubation of the previously obtained mixture, for which generally low-height bins are used (preferably no more than 40 cm tall), which are filled with such mixture and covered with some porous material, for example, surgical fabric.

(12) This incubation process is carried out for 10 to 45 days, time that will depend mainly on the humidity of the mixture and the complete population of the raw material with the fungus.

(13) In a particular model of the invention, the incubation step is carried out at a room temperature close to 30° C., so that the mixture remains at such temperature throughout the incubation period.

(14) The environmental humidity during the incubation period generally ranges between 50 and 60%. However, once the incubation stage is complete, the resulting dough is subjected to drying at a temperature between 35° C. and 55° C. until a final humidity of the material is reached between 5% and 10%.

(15) Finally, the process includes the stage of extraction of the coffee oil by means of solvents and equipment that are fully known and normally used for extraction procedures of chemical compounds. In this sense, this stage starts with the intimate combination of the selected solvent with the dry dough coming from the previous stage, followed by alternating phases of vigorous agitation and rest for a period that can vary between 1 and 3 days. The final phase of distillation and recovery of coffee oil can be carried out with the help of a rotatory evaporator equipment or something similar.

(16) In a particular realization, the solvent used for the extraction is hexane.

EXAMPLE

(17) In order to show the operation and advantages of the process according to this invention, below, we present a comparative example between the extraction of coffee oil through the process disclosed herein and the extraction of coffee oil through a typical mechanism previously known in the state of the art using carbon dioxide.

(18) Used Experimental Conditions

(19) Using bags 60 cm high and 5 meters long with surgical fabric filters every 40 cm, 10 kg of spent coffee grounds from Foodex Manizales, (Company that produces soluble coffee) were inoculated with 0.5 Kg of mycelium of macromycete from the commercial Laboratory of Bogota, Colombia. The incubation process was carried out for a period of 30 days until the complete population of the spent coffee grounds by the mycelium is achieved. Subsequently, such spent coffee grounds were dried in a drying oven at a temperature of 40° C. for 24 hours until achieving a humidity of 10%. Finally, the dry waste was subjected to a commercial Hexane extraction process and the same process used in edible oils.

(20) On the other hand, the experimental conditions necessary to carry out the extraction of edible oils using carbon dioxide gas are described in detail in the literature.

(21) Evaluated Results

(22) Once the extraction processes carried out were completed, the following experimental results were evaluated:

(23) 1) Percentage of performance: Amount of coffee oil extracted by each process, divided by the amount of coffee waste used initially and multiplied by one hundred.

(24) 2) Color: Visual appearance offered to the naked eye, that is, without using equipment or special mechanisms to determine the color of a fluid.

(25) 3) Other organoleptic characteristics: Other physical properties of the coffee oil obtained, including smell, taste, texture, among others.

(26) 4) For some calculations the following formulas were used:

(27) Calculation of Humidity:

(28) $\%H_{2}O=\frac{\mathrm{PI}-\mathrm{PF}}{\mathrm{PI}}\star 100.$
Calculation of Remaining Humidity:

(29) $\mathrm{Humid}\mathrm{fraction}=\frac{\mathrm{Completely}\mathrm{dry}\mathrm{sample}}{\mathrm{Humid}\mathrm{Sample}}\frac{\mathrm{Completely}\mathrm{dry}\mathrm{sample}\mathrm{for}\mathrm{experimenting}}{\mathrm{Humid}\mathrm{sample}\mathrm{for}\mathrm{experimenting}}=\mathrm{Humid}\mathrm{fraction}\mathrm{Ideal}\mathrm{water}\mathrm{weight}=\mathrm{Humid}\mathrm{Sample}-\mathrm{Completely}\mathrm{dry}\mathrm{sample}\text{}\mathrm{Actual}\mathrm{water}\mathrm{weight}=\mathrm{Humid}\mathrm{Sample}-\mathrm{Dry}\mathrm{sample}\mathrm{at}110°C.\%\mathrm{Remaining}\mathrm{Humid}\mathrm{in}\mathrm{the}\mathrm{Sample}=\frac{\mathrm{Actual}\mathrm{water}\mathrm{weight}}{\mathrm{Ideal}\mathrm{water}\mathrm{weight}}\star 100\%.$
Weight of the completely dry spent coffee grounds:
Dry spent coffee=Dry sample−Dry sample*Humidity

(30) TABLE-US-00001 Process according to Process the prior state according to Additional of the art the invention observations Performance 12% 16.7% The times percentage correspond to average values Color of the Dark brown Transparent/ In FIG. 4 the extracted oil. Slightly yellow marked difference in the color of the extracted oil is observed Other Coffee smell Nutty smell The flavor of the organoleptic oil obtained by the characteristics process of this invention is similar to that of the almond, with a smooth texture like banana oil.

(31) From the above, it is possible to say that the extraction process disclosed in this invention allows to effectively eliminate the characteristic brown color of coffee oil from spent coffee grounds or coffee beans, a characteristic that is not achieved with the extraction processes previously known in the state of the art basically because they don't comprise stages of treatment of the raw material (spent coffee grounds or whole or deteriorated coffee beans).

(32) The effective clarification of coffee oil drastically favors its usefulness in the cosmetology, medicinal, personal hygiene and food industries, giving added value to a product commonly treated as waste in the coffee industry.

(33) Additionally, it is pertinent to note that the transparent (or slightly yellowish) coffee oil obtained with the process disclosed here is the result of the treatment of the raw material with macromycetes, but not with the use of chemical products typically used for discoloration processes (for example, hydrogen peroxide and alkaline earth metal chlorides) or the use of very expensive physical processes such as activated carbon filtration.

(34) On the other hand, the performance percentage achieved with the extraction process of this invention (16.7%) ensures the profitability of the process and further demonstrates that such process does not adversely affect the amount of oil obtained.

(35) In fact, the quality of the obtained oil is similar to that of the oils extracted with chemical processes already known in the prior art, but showing serious differences in color and odor, characteristics that broaden the spectrum of use of such coffee oil in different technological sectors, particularly in food and cosmetology.