SOLUBLE BEVERAGE POWDERED COFFEE CONSISTING OF A DRY COFFEE EXTRACT.

Abstract

The present invention relates to a soluble beverage powder consisting of dry coffee extract, the powder having a color difference AE with respect to gold below 100, 5 10 15 20 25 wherein the structural density of the powder is from 0.7 to 1.4 g / ml, wherein the powder comprises particles comprising at least one plate having an average thickness of between 0.3 and 90 microns and two or more plates comprised within a particle are substantially parallel, wherein substantially parallel means that the plates are within 10 degrees of being parallel to each other.

Description

INSTANT COFFEE POWDER FIELD OF INVENTION The present invention relates to a soluble beverage powder consisting of a dried coffee extract. In particular, it relates to a soluble coffee powder having a golden appearance. Additional aspects of the invention include a powder mix for preparing a beverage and a process for manufacturing a soluble beverage powder. BACKGROUND OF THE INVENTION For many years, instant coffee producers have sought to improve the acceptance of this type of coffee compared to roasted and ground coffee. Much effort has been invested in optimizing the flavor and aroma of instant coffee, and due to the success of these technical advances, some instant coffees are now marketed as premium products. Premium products are those that consumers consider superior and particularly luxurious. However, progress in the appearance of instant coffee has been slower. There is a need for technologies that can deliver instant coffee with a premium appearance, for example, to complement a premium taste and aroma and enhance the consumer experience in terms of visual identity. In many countries, regulations require that pure instant coffee can only consist of coffee. This presents challenges in providing a novel and appealing appearance, as, for example, the inclusion of a color pigment would not be permitted. No reference to prior art documents in this This specification should be considered as an admission that such prior technique is widely known or is part of the common knowledge in the field. Where used in this specification, the words “comprises,” “which comprises,” and similar words should not be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean that they include, but are not limited to. BRIEF DESCRIPTION OF THE INVENTION An objective of the present invention is to improve the prior art and provide an improved technical solution for providing a premium appearance in soluble powders for beverages. The objective of the present invention is achieved by the subject matter of the independent claims. The dependent claims further elaborate on the idea of ​​the present invention.Accordingly, the present invention provides, in a first aspect, a soluble beverage powder consisting of dried coffee extract, the powder having a color difference ΔE with respect to gold of less than 100. In a second aspect, the invention relates to a powder mix for preparing a beverage comprising the soluble beverage powder of the first aspect. A third aspect of the invention relates to a process for preparing the soluble beverage powder of the first aspect, the process comprising providing a coffee extract having a total solids content of less than 25% and drying the coffee extract. Yet another aspect of the invention is a process for preparing a soluble beverage powder, the process comprising: i. providing a coffee extract having a total solids content of less than 25%. ία íL freeze the coffee extract having a total solids content of less than 25 I by unidirectional freezing; iii. break the frozen coffee extract to a particle size Dí a of 0.05 mm to 10 mm; and iv, dry the frozen coffee extract. Surprisingly, inventors have discovered that a coffee extract can be dried in such a way as to produce a soluble coffee powder with the appearance of the precious metal gold. Gold has been associated with wealth and luxury throughout history. Gold has a distinctive appearance, possessing both a golden hue and a specular reflection characteristic of polished metals. The inventors surprisingly discovered that drying a coffee extract in a process that favors the formation of dried coffee plates arranged in separate, parallel layers produces a soluble coffee powder with a golden appearance, especially when the coffee extract is dried from a low total solids content. BRIEF DESCRIPTION OF THE FIGURES Figures 1a, 1b, 1c and 1d show scanning electron microscope images of soluble beverage powders prepared according to the Example 1 where the total solids content (TSC) of the coffee extract before drying was 10% (Figure 1a), 15% (Figure 1b), 20% (Figure 1c), and 40% (Figure 1d). The white scale bar represents 500 microns in the images on the left and 100 microns in the images on the right. DETAILED DESCRIPTION OF THE INVENTION Accordingly, the present invention relates in part to a soluble beverage powder consisting of dried coffee extract, the powder having a color difference ΔE with respect to gold below TOO, for example, below 95, 94, 93, 92, 91,90,89, 88, 87,86, ü 85. The CIE 1976 L*a*b* color scale (hereafter CIELAS) is a color measurement method proposed by the Commission Internationale de résolaire (CIE) [CIE Technical Report, Colormetry, 2nd Edition, CIE 15.2 - 1986, corrected reprint 1996]. The CIELAB color space is produced when the quantities are plotted. L*, a*, b* in rectangular coordinates. The L* coordinate of an object is the light intensity measured on a scale from 0 (black) to 100 (absolute white). The a* and b* coordinates have no specific numerical limits. The a* parameter ranges from pure green (negative a*) to pure red (positive a*), while b* ranges from pure blue (negative b*) to pure yellow (positive b*). In the CIELAB color space, the color difference can be calculated as a single value by taking into account the differences between the L*, a*, and b* values ​​of the two samples. The color difference pE is calculated as follows: ΔΕ “ + (ώαψ í (Ab*)2 In the context of the present invention, the color gold is considered to have CIELAB LM56.9 values, a*“1.9 and b*~87,1. This corresponds to the hexadecimal code for the color gold, ffd7ÓO [web document]<encycoiorpedia.com / ffd700> [Accessed January 30, 2019] Therefore, pE of gold is calculated from the measured values ​​of L* a* yb* as follows: ÁK áelaro ~ 87? + Or + 2? + (b* - 87? Color measurement can be performed with a commercial colorimeter, such as a HunterLab Colorfiex device (CXW51), for example, using the illuminating setting ntsZobserver D65 / 45' ± 2' excluding specular reflection. Dry coffee extract may comprise residual water, for example, dry coffee extract may comprise less than 5% by weight of water, for example, less than 4% by weight of water. Polished metals exhibit specular reflection, where light The incident light is reflected in a single outward direction. Specular reflection is sometimes referred to as brightness. One aspect of the invention provides a soluble beverage powder having specular reflection, for example, a brightness at 60° of geometry of at least 0.5 brightness units. The brightness can be measured, for example, with a CIE-C illuminant and a standard CIE observer. The brightness can be measured using a Gardner 8YK meter. Micro-Tri-Gloss, for example, equipped with a holder adapted to cosmetic powders. In one embodiment, the soluble beverage powder of the invention, having a gold color difference ΔE below W0, has a brightness at 60° of geometry of at least 0.5 brightness units, for example, at least 0.6 brightness units, for example, between 0.5 and 1.7 brightness units. It is advantageous that the invention provides a material that, like gold metal, has a gold color combined with specular reflectivity. The inventors have discovered that different total solids content of the coffee extract dried to produce the soluble beverage powder of the invention results in different structural densities of the powder. Structural density, in turn, is related to the color of the powder. A golden color can be obtained with low structural densities. In one embodiment, the structural density of the powder is 0.7 to 1.4 g / ml, for example, 0.9 to 1.3 g / ml. The apparent density of the powder (for example, measured by Hg porosimetry at 0.4 psia) is 0.15 to 0.35 g / ml, for example, 0.18 to 0.30 g / ml. According to the present invention, the term density is the mass per unit volume of a material. For porous powders, three terms are commonly used: apparent density, structural density, and compaction density. Structural density (also called true or absolute density) is obtained when the measured volume excludes the pores and voids between particles within the bulk sample. Apparent density is defined as the unit weight per unit volume of granule after the volume of the largest open pores (greater than a specific size, extrusion pressure Hg at 0.4 psia) has been subtracted. Compaction density is the density obtained by filling a container with the sample material and vibrating it to obtain near optimum packing. Compaction density includes voids between particles in the volume, while apparent density does not.In structural density, the volume used in the density calculation excludes both pores and void spaces between particles. Structural density can be measured, for example, by pulsed excitation, helium pycnometry, or mercury porosimetry. In one embodiment, the powder comprises particles comprising at least one plate having an average thickness of between 0.3 and 90 microns, for example, between 1 and 60 microns, for example, 5 and 50 microns. Plates of such thicknesses consisting of dried coffee extract are an example of a structure capable of providing golden color and specular reflectance. For example, at least 30% by weight of the soluble beverage powder of the invention may be particles comprising at least less a plate having an average thickness of between 0.3 and 90 microns. In the present invention, the term “plate” is used in the sense of a thin, flat sheet. For example, a plate may be a smooth, flat, relatively thin solid body of uniform thickness. In one embodiment, the at least one plate has a maximum dimension at least 5 to 10 times greater than its average thickness, for example, at least 50 times greater than its average thickness. In one embodiment, the at least one plate has a dimension perpendicular to its maximum dimension that is at least 5 times greater than its average thickness. In one embodiment, the at least one plate has a thickness that varies by less than a factor of four, for example, less than a factor of two. The degree to which the particles contained within the soluble beverage powder are plate-like (or “flaky”) can be measured by profilometry.For example, the projected area and average height (thickness) of approximately 200 to 500 particles dispersed manually on a measuring platform where they naturally lie in their plane (i.e., along their two largest dimensions) can be measured. A suitable measuring device would be a Keyence VR5200 3D profilometer. Fine particles can be removed before measurement. A sagging index is obtained by dividing the height by the square root of the projected area. An average index is calculated, weighted by the apparent size of the particles. In one modality, the dust comprises particles having an average ratio of particle height to the square root of projected area less than 0.4, for example, less than 0.35, and for example, less than 0.3.In one embodiment, two or more plates comprised within a particle are substantially parallel, for example, at least 30% by weight of the particles comprise two or more substantially parallel plates, for example, three or more, for example, four or more, for example, five or more. In the context of the present invention, The term “substantially parallel” means that the plates are within 10 degrees of each other. Not wishing to be limited by theory, the inventors believe that the thin parallel plates of dried coffee extract effectively generate both a golden color and specular reflectance. Light interacting with the thin plates undergoes some selective absorption to provide the golden color, but not enough absorption to cause a dark brown appearance. Each plate struck by light causes a degree of specular reflection; the parallel plates result in light that has passed through one plate and reached the surface of a second plate being reflected at approximately the same angle as the light reflected from the first plate, thus creating an aligned specular brightness. In one embodiment, two or more substantially parallel plates are separated by a space, for example, an air gap. The space between two substantially parallel plates may be greater than or equal to the average thickness of the plates; for example, it may be greater than the average thickness of the plates and less than W times the average thickness of the plates. The substantially parallel plates may have the form of a laminated structure. Such a structure, when enlarged, resembles the laminar structure of puff pastry or a sponge. Two or more substantially parallel plates separated by a space may have cohesive elements between them, for example, dust particles 20 may comprise a foam structure, with elongated pores between the plates, the plates forming parallel walls of the foam. In one embodiment, the soluble beverage powder is a glassy amorphous solid, for example, a glassy amorphous solid at 20°C. A glassy amorphous solid exhibits a glass transition temperature. A glass transition temperature can be measured, for example, by differential scanning calorimetry. The soluble beverage powder may be free of crystalline material; for example, crystals cannot be observed under a microscope using polarized light. Another aspect of the invention relates to a powder mix for preparing a beverage. The powder mix comprises the soluble beverage powder of the invention. The powder mix may be, for example, a mixture of coffee, sugar, and powdered milk that can be added to water to form a sweetened white coffee. The powder mix may also be, for example, a mixture of the soluble beverage powder of the invention with a conventional pure soluble coffee powder. An additional aspect of the invention provides a process for preparing the soluble beverage powder of the invention. The process comprises providing a coffee extract having a total solids content of less than 25% and drying the coffee extract. The total solids content refers to the mass of matter in a solution or suspension. The total solids content of a coffee solution or suspension is defined as the weight of the dried coffee residue expressed as a percentage of the original coffee solution or suspension by weight / weight percent (% w / w). Yet another aspect of the invention provides a process for making a soluble beverage powder, the process comprising; i. provide a coffee extract having a total solids content of less than 25%; i. freeze the coffee extract having a solids content of less than 25% by unidirectional freezing; iii, break the frozen coffee extract to a particle size D<3 of 0.05 mm to 10 mm; and iv, dry the frozen coffee extract (e.g., the frozen coffee extract to a particle size of 0.05 mm to 10 mm). During unidirectional freezing, water freezes into ice along a single plane. This can be achieved, for example, by placing a container of liquid coffee extract in contact with a single flat freezing surface such that ice crystal growth occurs perpendicular to the freezing surface, or by placing liquid coffee between multiple parallel cooling plates such that crystal growth occurs perpendicular to the parallel freezing surfaces. Not wishing to be limited by theory, the inventors believe that during the unidirectional freezing of a coffee extract with low solids content, a concentration of the coffee solutes freezes, and as ice crystals form at the flat freezing front, they create thin plates of coffee extract between them.After the ice sublimates during drying, this results in a porous structure comprising thin, parallel plates of dried coffee extract. In one embodiment, freezing is carried out using a block freezer. In another embodiment, freezing is carried out between parallel cooling plates, for example, using a parallel-plate freezer. In yet another embodiment, the drying of the frozen coffee extract is carried out under vacuum, for example, for 1 to 4 hours. The breakdown of the frozen coffee extract can be carried out by grinding; for example, the frozen extract can first be crushed using a grinder and then ground using a crusher. In one embodiment, the coffee extract is not gasified before freezing. Gasification of the coffee extract before freezing disrupts the orderly growth of the ice crystals.25 Yet another aspect of the invention provides a process for. To manufacture a soluble beverage powder, the process comprises: providing a coffee extract having a total solids content of less than 25%; freezing the coffee extract having a total solids content of less than 25% at a temperature between -80 and -30°C (e.g., between -50 and -30°C) for a period of between 1 and 12 hours; breaking down the frozen coffee extract to a particle size D<3 of 0.05 mm to 10 mm; and drying the frozen coffee extract (e.g., the frozen coffee extract with a particle size D<3 of 0.05 mm to 10 mm). The coffee extract may be provided by an extraction process that promotes a degree of hydrolysis. Chemical transformations in roasted and ground coffee, such as hydrolysis, can occur during extraction, for example, the cleavage of high molecular mass polysaccharides, resulting in their solubilization.In one embodiment, roasted and ground coffee is extracted with a total solids content of less than 25%. For example, providing a coffee extract with a total solids content of less than 25% can be done without diluting an extract with a total solids content greater than 25%. Extracting coffee with a low total solids content, for example, below 25%, provides a flavor and aroma that closely replicates a beverage made from roasted and ground coffee. Slow freezing also preserves desirable aroma compounds. In one embodiment, the roasted and ground coffee is not hydrolyzed during the extraction process to provide the coffee extract. In one embodiment, the coffee extract is an extract of Arabica coffee (Coffea arugula). In another embodiment, the coffee extract is an extract of Robusta coffee (Coffea cannabis).In one form, coffee extract is an extract of a mixture of Arabica coffee (Coffea arab / ca) and Robusta coffee (Coffea canephGra). In one method, the coffee extract is concentrated before freezing to accelerate the freezing process. Preferably, the coffee extract is concentrated without the application of heat to preserve as much of the desired aroma as possible. The coffee extract can be concentrated by membrane concentration; for example, roasted and ground coffee can be extracted to a total solids content below 12%, and then the extract can be concentrated to a total solids content below 25%. The coffee extract can also be concentrated by freeze concentration; for example, roasted and ground coffee can be extracted to a total solids content below 12%, and then the extract can be concentrated to a total solids content below 25%. In one modality, the process includes: i. provide a coffee extract having a total solids content of less than 25%; h. Freeze the coffee extract having a total solids content of less than 25% by unidirectional freezing at a temperature between -80 and -30 °C (e.g., between -50 and 30 °C) for a time between 1 and 1.2 hours; iii. break the frozen coffee extract to a particle size D,t?3 of 0.05 mm to 10 mm; and iv; dry the frozen coffee extract (e.g., the frozen coffee extract with a particle size O4.3 of 0.05 mm to 10 mm). The values ​​of D, d, and d are common methods for describing a particle size distribution. The d (sometimes written D90) is the diameter where 90% of the particles in the sample by volume have a diameter below that value. In the context of the present invention, the d by mass is equivalent to the d by volume. Similarly, d is the diameter where 10% of the particles in the sample by volume have a diameter below that value. The term 'particle size D43' is conventionally used in the present invention and is sometimes called the volume mean diameter. The d, d, and d values ​​of powders can be conveniently measured by digital image analysis (such as using a Camsizer XT). Other measurement techniques for particle size distribution may be used depending on the nature of the sample.For example, dispersions are commonly measured using laser light scattering (such as using a Malvem 3000 Mastersizer), while powders with particle sizes large enough to be conveniently sieved can be measured by sieving. Those skilled in the art will understand that they may freely combine all the features of the present invention described herein. In particular, the features described for the product of the present invention may be combined with the process of the present invention and vice versa. Furthermore, the features described for different embodiments of the present invention may be combined; where known equivalents exist for specific features, such equivalents shall be incorporated as if specifically mentioned in this specification. Other advantages and features of the present invention are evident from the non-limiting figures and examples. Examples Example 1: Coffee powder produced by freezing on tray plates Coffee extracts with a range of different values ​​of total content! of solids (5, 15, 35 and 45%) were placed in a rectangular tray container maintained at -40 °C The extracts were allowed to solidify (1-4 h) after which they were ground with a Frewift grinding mill and ground with an Urschel mill with a separation of 5-2mm. The resulting frozen extract was placed in freeze-drying trays and vacuum-dried on temperature ramps from 10°C to 8°C to 60°C to 40°C for three hours, and then held for fifteen hours at 40°C. Coffee extracts with a total solids content of 5% and 15% resulted in a golden, shiny powder. The color of the powders was measured using a HunterLab Colorflex device (CX1051), with illuminant / observaddf setting 065 / 45° ± 2 and a 47 mm sample holder. The color difference pE of gold was calculated from the measured values ​​(three repetitions) of L*, a* and b* as follows: ΔE of gold = Specular reflectance of the samples was measured using a Gardner Micro-Tri-Gloss meter equipped with a holder adapted for cosmetic powders. Gloss was measured with 60° incident light, a CIE-C illuminator, and a CIE standard observer. The instrument is calibrated using a standard black tile with an assigned gloss value of 100 gloss units. To perform the measurement, powder was placed in the measuring cup, its surface was leveled, and then the gloss meter was adjusted, ensuring a tight seal to exclude room lighting. This procedure was repeated 6 times for each sample. The results of the distance between the ero and the brightness are shown in the Table 1. Table 1 Sample Particle size 04.3 Ϊ pE of | gold Brightness units at 60° I TC before drying of | 1.4% Ho was measured | 75.2 1.63 i TC before drying of 358 microns | 84.8 0.65 j 5% TC before drying of 716 microns 90.1 0.52 | 15% TC before drying of 964 microns | 89-9 0.22 35 % TC before drying of 1223 microns 0.20 45 % | 87.9 All samples were examined under a microscope with polarized light and no crystals were observed. The sample with a total solids content of 5% before drying was examined using a Kéyence VR5200 3D perfiometer. The powder was sieved prior to measurement to remove particles smaller than 500 microns. The average height (thickness) of approximately 200 to 500 particles, manually dispersed on the measuring platform, was measured. The particles naturally lie in their plane (i.e., along their two longest dimensions). An acidity index is obtained by dividing the height by the square root of the projected area. Acidity index ~ average particle height ^ / projected particle size SWtce of f lucidity x Jareapr&yeot&da. Size-weighted flux index ~ ————------------------X y projected area It was found that the sample had a weighted average size index of 0.25. A commercially available soluble coffee was found to have an index of 0.42. Fíemela 2: Microscopy and measurement of the porosity of coffee powders Soluble coffee powders were produced in the same way as in Example 1 with total solids content values ​​before drying of 10%, 15%, <20%, and 40%. Coffee extracts with a total solids content of 10%, 15%, and 20% resulted in a golden, shiny powder. Scanning electron microscopy was used to examine the powders. The SEM images are shown in Figure 1. It can be observed that while the coffee extracts with total solids content of 10% (Figure 1a), 15% (Figure 1b), and 20% (Figure 1c) resulted in a “flaky” microstructure with thin parallel plates, the extract with a total solids content of 40% (Figure 1d) led to a less porous structure with thicker walls. Mercury porasymmetry data were also obtained for 10%, 15%, and 20% TC samples to evaluate bulk density, structural density, and open pore volume. An AutoPare IV 9520 was used for structure evaluation (Micromeritics Inc., Norcrose, GA, USA). The operating pressure for Hg intrusion was 0.4 psia to 9000 psia (low pressure from 0.4 psia to 40 psia and high pressure from 20 to 9000 psia). The pore diameter under this pressure ranged from 500 to 0.01 microns. The reported data were volume (ml / g) at different pore diameters. Approximately 0.1 to 0.4 g of samples were accurately weighed and packed into a penetrometer (volume 3.5 ml, capillary stem or neck diameter 0.3 mm and stem volume 0.5 ml). After inserting the penetrometer into the lower pressure port, the sample was evacuated at 1.1 psia / min, then changed to an average rate of 0.5 psia and a rapid rate at 900 pm Hg. The evacuation target was 60 pm Hg. After reaching the target, the evacuation continued for 5 min before filling the Hg. The measurement was performed under a set time equilibrium. That is, the w pressure points at which the data were taken and the time elapsed at that pressure were set in the established time equilibrium mode (10 s). Approximately 140 data points were collected across the pressure ranges. The volume of open pores per gram of product in the diameter range of 0.001 to 500 microns (ym) gives the "open pore volume". Apparent density is defined as the unit weight per unit volume of granule after the volume of the largest open pores (greater than a specific size, extrusion pressure Hg at 0.4 psia) has been subtracted. A typical value for the largest pore included in the apparent density is 180 microns. Structural density is calculated after the volume of all pores larger than approximately 0.005 microns has been excluded from the volume assumed to be occupied by the material. The results are presented in the table below. Table 2 Sample Density Density j Apparent total structural volume § of pores ................—....._____...____...J...........— 0.4 psia open TC before drying of j io% | 0.19 g / ml 0.93 g / ml 4.21 ml / g TC before drying of i 15% | 0.24 g / ml 1.07 g / ml 3.17 ml / g TC before drying of i 20% | 0.30 g / ml 1.21 g / ml 2.49 ml / g Example 3: Golden and bright coffee powder produced on flat plates Roasted and ground Arabica coffee was extracted with a total solids content of 10%. Membrane concentrating was used to increase the total solids content to 20%. The extract was slowly heated between parallel plates at a temperature between -35°C and -45°C for 12 hours. No gassing was applied. The freeze-dried powder had a particle size of approximately 1.5 mm and a golden color and glossy appearance.

Claims

Ί. Soluble beverage powder consisting of dry coffee extract, the powder having a color difference ΛE with respect to gold below 100.

2. A soluble beverage powder according to claim 1 having a brightness at 60° geometry of at least 0.5 brightness units.

3. A soluble drink powder according to claim 1 or claim 2, characterized in that the structural density of the powder is from 0.7 to 1.4 g / ml.

4. A soluble beverage powder according to any one of claims 1 to 3, characterized in that the powder comprises particles comprising at least one plate having an average thickness of between 0.3 and 90 microns.

5. A soluble beverage powder according to claim 4, characterized in that two or more plates comprised within a particle are substantially parallel.

6. A soluble beverage powder according to claim 5, characterized in that the two or more substantially parallel plates are separated by a space.

7. A soluble beverage powder according to any one of claims 1 to 6, characterized in that the powder is a glassy amorphous solid.

8. Powder mixture for preparing a beverage comprising the soluble beverage powder of any one of claims 1 to 7.

9. Process for preparing a soluble beverage powder according to any one of claims 1 to 7, the process comprising providing a coffee extract having a total solids content of less than 25% and drying the coffee extract.

10. Process for preparing a soluble beverage powder, the process comprising: i. providing a coffee extract having a total solids content of less than 25%; ii. freezing the coffee extract having a total solids content of less than 25% by single-stage freezing; iii. breaking down the frozen coffee extract to a particle size D<3 of 0.05 mm to 10 mm; and drying the frozen coffee extract.

11. A process according to claim 9 or claim 10 characterized in that the coffee extract is extracted to a total solids content of less than 25%.

12. A process according to any one of claims 9 to 11 characterized in that the drying is carried out under vacuum.

13. A process according to any one of claims 10 to 12, characterized in that the freezing is carried out at a temperature between -8°C and -30°C for a period of between 1 and 12 hours.

14. A process according to any one of claims 10 to 13, characterized in that the freezing is carried out between parallel cooling plates.