COMPRESSED SOLID MILK TABLETS AND METHOD FOR MAKING THE SAME

Abstract

The present invention relates to compressed solid milk tablets, a method for producing the same and a modular system for carrying out said method. The method comprises: (a) compressing milk powder to obtain compressed solid milk units with a mechanical strength between 10 kPa and 300 kPa, (b) humidifying the compressed solid milk units by exposing them in a humidifying chamber to humid air having a relative humidity of more than 95% and a temperature between 60 and 90° C., wherein the humid air comprises condensed water vapour, and (c) drying the humidified and compressed solid milk units to obtain compressed solid milk tablets. The tablets obtained by this method have a mechanical strength between 20 kPa and 1000 kPa, a core/crust structure, wherein the crust comprises milk particles that are solidified and fused in parallel and perpendicular planes, relative to the tablet surface, and a friability of less than 5%.

Claims

1-30. (canceled)

31. A method for preparing compressed solid milk tablets, comprising: (a) compressing milk powder to obtain compressed solid milk units with a mechanical strength of between 10 kPa and 300 kPa, (b) humidifying the compressed solid milk units by exposing the units in a humidifying chamber to humid air having a relative humidity of more than 95% and a temperature of between 60 and 90° C., wherein the humid air comprises condensed water droplets, wherein the exposure time of the solid milk units in the humidifying chamber is less than 5 seconds, and (c) drying the humidified and compressed solid milk units to obtain compressed solid milk tablets.

32. The method according to claim 31, wherein the compaction ratio of the compressed solid milk units obtained in step (a) lies between 0.30 and 0.65.

33. The method according to claim 31, wherein the milk powder comprises particles having an average size comprised between 30 μm and 700 μm.

34. The method according to claim 31, wherein the compressed solid milk units have a total surface area of between 10 and 50 cm.sup.2.

35. The method according to claim 31, wherein the solid milk units have a total weight of between 1 and 10 grams.

36. The method according to claim 31, wherein the compressed solid milk units have a temperature of between 4 and 30° C. upon entry of the humidifying chamber in step (b).

37. The method according to claim 31, wherein the exposure time in the humidifying chamber is between 1 and 4 seconds.

38. The method according to claim 31, wherein the humidifying chamber is provided with humid air that is generated by boiling or holding water at a temperature which is elevated with respect to the temperature to which the solid milk units are exposed in the humidifying chamber to allow condensing of water vapour to occur.

39. The method according to claim 31, herein the humidifying chamber is provided with air that is generated by boiling or holding water at a temperature which is at least 50° C. higher than the temperature in the humidifying chamber to which the solid compressed units are exposed to allow condensing of water vapour to occur.

40. The method according to claim 31, wherein in step (b) the solid milk units absorb an amount of water in the range of from 0.3 to 4 mg water per cm.sup.2 surface area of the solid milk unit.

41. The method according to claim 31, wherein in step (b) the solid milk units absorb an amount of water in the range of from 0.10 to 2.0 wt during humidification.

42. The method according to claim 31, wherein in step (b), the solid milk units are conveyed through the humidifying chamber.

43. The method according to claim 31, wherein the drying step is carried out by infrared radiation.

44. The method according to claim 31, wherein the drying step results in a moisture level of the solid milk tablet between about +/−0.2% of the initial moisture level of the milk powder.

45. The method according to claim 31, wherein after drying, the solid milk tablets are packaged in a sealed package comprising a replacement gas such as nitrogen and/or carbon dioxide.

46. The method according to claim 31, wherein the obtained solid milk tablets have a friability of less than 5%.

47. A tablet obtainable by the method according to claim 31.

48. A compressed solid milk tablet having a mechanical strength of between 20 kPa and 1000 kP and a core/crust structure, wherein the crust comprises milk particles that are solidified and fused in parallel and perpendicular planes, relative to the tablet surface and the solid milk tablet has a friability of less than 5%.

49. The compressed solid milk tablet according to claim 48, wherein the crust has an average thickness comprised between 150 μm and 1.5 mm.

50. The compressed solid milk tablet according to claim 48, having a core with density that is lower than the density of the crust.

51. The compressed solid milk tablet according to claim 48, wherein the average thickness of the crust is at least the thickness of two rows of milk particles as visible in the core of the solid milk tablet or as comprised by the milk powder used for preparing the solid milk tablets.

52. The compressed solid milk tablet according to claim 48, having a compaction ratio that lies between 0.30 and 0.65.

53. The compressed solid milk tablet according to claim 48, having a total surface area between 10 and 50 cm.sup.2.

54. The compressed solid milk tablet according to claim 48, having a total weight between 1 and 10 grams.

55. A modular system for preparing a tablet according to claim 48, comprising: (a) a device for compressing milk powder to obtain compressed solid milk units with a mechanical strength of between 10 kPa and 300 kPa, (b) a humidifying system including a humidifying chamber for humidifying the compressed solid milk units and means for producing a humid environment in the humidifying chamber, the environment comprising a relative humidity of more than 95%, a temperature of between 60 and 90° C. and condensed water droplets, to obtain compressed humidified and compressed solid milk units, (c) a drying device for drying the humidified and compressed solid milk units, and (d) means for conveying or providing solid milk units from the compression device to the humidifying system and subsequently to the drying device for drying.

Description

DESCRIPTION OF THE FIGURES

[0185] FIG. 1 shows a SEM picture of the surface of a solid milk tablet with surface porosity of 10%.

[0186] FIG. 2 shows a SEM picture of the surface of a solid milk tablet with surface porosity of 15%.

EXAMPLES

Example 1: Compressing of Dry Milk Particles to Provide Solid Milk Units with Predetermined Hardness

[0187] Dry milk powders of three representative nutritional formulations for feeding infants with the following characteristics were used to test tabletting behaviour and setting up calibration curves. Besides these macronutrients, suitable levels of vitamins and minerals were present as well. The size of powder can be determined by means of a laser diffraction particle size analyser (Malvern Mastersizer 2000 with Scirocco 2000 dry powder dispenser).

TABLE-US-00001 TABLE 1 Characteristics of three different recipes of dry milk particles. Particle size distribution* Batch P F C M BD <150 >150 >250 >400 >600 A 9.3 20.8 40.8 2.62 0.51 3 27 40 22 8 B 9.4 24.0 36.6 2.10 0.56 8 31 37 15 9 C 10.7 20.6 39.3 2.13 0.58 2 11 54 25 8 P = protein content in wt %, F = Fat content in wt %, C = carbohydrate content in wt %, M = moisture content in wt %, BD = bulk density in g/cm.sup.3. *Particle size distribution is given as fraction of the total amount of particles (expressed in vol %) in a certain particle diameter class (expressed in μm).

[0188] Compression was achieved using a rotary press (Eurotab Technologies, France) by compressing between 4.8 and 5.0 gram dry infant milk powder to obtain solid milk units with varying compaction ratios and hardness/mechanical strength. The dimensions of the units as obtained were 25×25 mm due to the dimension of the compression die. The height of the tablets is slightly variable (ranging between 9 and 13 mm) due to the selected compression pressure of between 1 and 40 MPa as exerted on the dry milk powder. The height of tablets of preferred hardness/mechanical strength was 10-12 mm.

[0189] Hardness of the tablets was determined using an 8M DR. SCHLEUNIGER® hardness tester as mentioned herein according to the manufacturer's instructions. Mechanical strength (in kPa) and compaction ratios were calculated according to the terms and definitions as mentioned above. To obtain statistically significant results and unless indicated otherwise, the hardness of a total of at least 20 tablets was determined for each batch of tablets made.

TABLE-US-00002 TABLE 2 Observed hardness (in N), mechanical strength (in kPa) and compaction ratios (CR) of three representative dry infant milk powder recipes at varying compaction heights of a standardized amount of compressed dry milk powder. Hardness (N) MS (kPa) Height (mm) Weight (g) CR Recipe A 13 21 12.62 4.95 0.50 29 48 11.97 4.93 0.53 38 65 11.73 4.93 0.54 57 100 1142 4.98 0.56 72 130 11.04 4.95 0.57 106 202 10.50 4.88 0.59 Recipe B 11 18 12.15 4.91 0.52 27 46 11.65 4.95 0.54 45 81 11.05 4.90 0.57 61 112 10.87 4.95 0.58 103 22 10.30 4.94 0.61 153 310 9.87 4.91 0.64 Recipe C 9 15 11.76 4.93 0.54 18 32 11.34 4.92 0.56 44 82 10.79 4.99 0.59 79 154 10.27 4.96 0.62 122 248 9.82 4.94 0.64 9 15 11.76 4.93 0.54 MS = Mechanical Strength (expressed in kPa), CR = Compaction Ratio, N = Newton.

[0190] Using incremental compression settings, calibration curves were readily obtained for all three recipes to be able to obtain solid milk units with mechanical strengths that ranged from about 10 kPa to about 300 kPa. As can be seen from the results in Table 2, some variation in the correlation between compression ratio and resulting mechanical strength was observed per powder batch. However, within batch variations were not significant and solid milk units of predictable and consistent mechanical strength could be obtained from a single powder batch by use of a single, straightforward calibration curve. Since dry milk powers are typically produced in large batches of easily 1000 kg, it is very convenient for the skilled person to preselect the desired solid milk unit hardness/mechanical strength by use of a single compression test using incremental compression settings. Conveniently, any observed variation in the resulting mechanical strength of different dry milk powder recipes or production batches could be corrected by selecting the appropriate compression setting. This allows production of compressed solid milk units with a preselected mechanical strength value/hardness that can subsequently be humidified and dried.

Example 2: Moistening and Drying of Compacted Milk Units with Preselected Hardness

[0191] Compressed solid milk units obtained by the method of Example 1 were conveyed with a conveyor belt from the rotary press through a humidifying chamber with a calculated volume of 7430 cm.sup.3. The humidifying chamber is open by two slits of 3 cm×12 cm that are present at the opposite sides from the two vertical, planar walls of the chamber to allow the tablets to traverse the chamber on the conveyor belt. The solid units were horizontally conveyed over a humidifying distance of 22.5 cm through the humidifying chamber after which the humidified solid milk units were conveyed through a drying chamber in which infra-red lamps were present for drying of the solid milks. The humidifying chamber was cylindrically shaped and positioned on its side, meaning the two opposite planar walls of the cylinder are positioned in an upright, vertical manner.

[0192] The weight increase of the units as a function of conveying speed through the humidifying chamber due to the absorbance of moisture was determined by conveying said units at pre-selected speeds through the humidifying chamber and deducting the weight of the non-humidified unit from the weight of the humidified unit. The amount of absorbed water by the tablets equates to a time spent in the humidified chamber which was controlled by the speed of the conveyor belt. This allows the use of a preselected conveyor belt speed to control water absorption by the units.

[0193] A pressurised boiler (Vaporettino LUX by Polti® S.p.A., Italy) was used for production of humid air comprising condensed water vapour for feeding into the humidifying chamber and operated according to the manufacturer's instructions. Before any humid air comprising condensed water vapour was fed into the humidifying chamber from the boiler, the device was fully heated up indicated by the “steam ready” indicator. Under these operating conditions, it could be felt that the water inside the pressurised boiler was boiling at the 3 bar capacity of the device. Humid air comprising condensed water vapour was constantly fed into the humidifying chamber from the device through the included flex (i.e. a hose). The humidifying chamber was equilibrated by feeding humid air comprising condensed water vapour into the chamber for an initial 15 to 30 minute time period during which the temperature in the chamber stabilised at around 70-72° C. and after which humid air with condensed water vapour continuously and visibly escaped from the chamber.

[0194] Performance of the humidifying chamber and repeatability of the obtained results was investigated by conveying eight different batches of 20 tablets each through said chamber. An average of 40.65 mg water was absorbed by the tablets at a belt speed of 3.5 m/min. With a standard deviation of 1.31 mg water, it was considered that the humidifying chamber provides good performance and provides repeatable results. It was concluded that the humidifying chamber provides a robust means to add a controlled and consistent amount of water to the compressed solid milks. Similar results were obtained using a humidification chamber with an increased length which was operated at a corresponding, increased conveyor belt speed (results not shown).

[0195] By changing the speed of the conveyor belt, the amount of water absorbed by the unit can thus be readily controlled using this set-up. Different conveyor speeds were tested and it was found that absorption levels of between 15 to 55 mg water per unit could be achieved that resulted in suitable solid milk tablets. By taking the dimensions of the tablets into account, the total amount of absorbed water was calculated per cm.sup.2 solid unit surface area.

[0196] The drying step was executed by immediately conveying solid milk tablets from the humidification chamber through a tunnel which was equipped with eight 2 kW IR lamps that were positioned such that homogeneous drying over all faces of the solid milks was achieved. The drying time needed to restore to the initial moisture levels of the solid milk before moistening was between about 10 and 60 seconds.

Example 3: Effect of Water/Moisture Absorption on Hardness/Mechanical Strength Increase

[0197] Solid milk units with a hardness ranging between 20N and 50N were obtained according to the method of Example 1. These units were humidified using the set-up as described in Example 2 to allow the units to absorb an amount of water as indicated in Table 3 which is between 20 and 50 mg per unit.

TABLE-US-00003 TABLE 3 Increase of hardness after humidifying and drying. Water H.A.P. H.A.D. Water H.A.P. H.A.D. addition (kPa/N) (kPa/N) addition (kPa/N) (kPa/N) 20 mg 33/19 108/62  20 mg 77/40 193/101 30 mg 33/19 145/83  30 mg 77/40 277/145 40 mg 35/20 221/125 40 mg 74/39 415/215 50 mg 28/16 309/172 50 mg 79/41 664/340 20 mg 56/30 152/82  20 mg 103/53  234/121 30 mg 55/29 203/108 30 mg 96/48 339/171 40 mg 51/27 262/139 40 mg 92/48 381/199 50 mg 54/29 510/269 50 mg 90/46 688/348 H.A.P. = Hardness after press means the hardness (in N) or mechanical strength (MS) of solid milks that were not yet subjected to moistening and drying. H.A.D. = Hardness after drying which means the hardness (in N) of tablets that have been moistened and dried. Corresponding mechanical strength values were calculated from the hardness values with the equation 2F/S, as described in detail above.

[0198] As can be seen in Table 3, it was surprisingly found that a correlation appears to be present in the sense that under the tested conditions the hardness increase from H.A.P. to H.A.D. with 20 mg water addition is 2.5 to 3 fold, with 30 mg about 4 fold, with 40 mg about 5 fold and with 50 mg about 9 fold.

[0199] The hardness/mechanical strength of the obtained tablets was scored as good. Both the observed HAP and HAD scores are considered to be more than suitable for purposes of both handling during manufacturing and transport of tablets to the consumer, respectively. Notably, solid milk tablets that absorbed 20 mg water (which equates to less than 0.5 wt % of the solid milk tablet) displayed good hardness/mechanical strength scores, especially with higher preselected H.A.P. settings.

Example 4: Shelf-Life Properties of the Solid Milk Tablets as Produced

[0200] Both hardness evolution and reconstitution behaviour was assessed over time of solid milk tablets produced with the present method. In particular, the shelf-life of tablets with a HAP value of about 30N (27-30N) and about 50N (46N-53N) that received about 20, 30, 40 or 50 mg water was tested.

[0201] Hardness/mechanical strength was determined as mentioned in Example 1. Hardness/mechanical strength of solid milk tablets was assessed over time to gain insight in the shelf-life properties of the solid milk tablets. To ensure a proper shelf-life assessment that closely reflects the real-life consumer situation, solid milk tablets were immediately packed after production in a sealed, air-tight package containing inert gas and stored under ambient temperature conditions. The thus packaged solid milk tablets were stored for 1, 3 and 6 months. The tablets were taken out of their protective environment by breaking the seal after which hardness values were determined. Hardness/mechanical strength values for the tested tablets did not change in a statistically significant manner over the indicated time-period.

[0202] Reconstitution behaviour was assessed by a standardized method that represents the consumer's way of preparing a ready-to-feed baby bottle. To this end, 6 solid milk tablets of the indicated HAP value and water addition as mentioned were placed in a baby bottle with 180 mL of water of 40° C. followed by standardized manual shaking performed by a single subject for 30 s. After 30 s of shaking the content of the baby bottle was poured into a sieve of which the meshes measured 630 μm. The presence of lumps was visually assessed. The estimation of the reconstitution score was determined by a visual assessment, taking into account the size of the remaining lumps. In the absence of lumps, the reconstitution score was 0. With the presence of lumps, a reconstitution score from 1 to 10 was awarded depending on the size of the lumps observed on the sieve. The score 10 corresponds to the fact that almost all the solid milks are retained on the sieve. The larger the lumps and the closer they are to the initial size of the solid, the higher the score. Reconstitution is acceptable if the score is less than or equal to 2. Obviously, a score of 1 or even 0 is more preferred.

[0203] Reconstitution behaviour of the stored tablets was determined using above mentioned hand-shaker method at 40° C. The solid milk tablets mentioned in Table 3 with a HAP value of about 30N (27-30N) that displayed a HAD value of between 82 and 269N, all exhibited a better than acceptable reconstitution value of 0 or 1 for tablets stored for up to 6 months. Reconstitution behaviour of these solid milk tablets was also determined after a short storage period of a week or less and found to range between 0 and 1.

[0204] The solid milks mentioned in Table 3 with a HAP value of about 50N (46-53N) and that displayed a HAD value of between 121 and 348N, all exhibited an acceptable reconstitution value of 1 or 2 for tablets stored for up to 6 months. Reconstitution behaviour of these solid milk tablets was also determined after a short storage period of a week or less and found to range between 0 and 2.

[0205] Similar reconstitution results were found for solid milks of Table 3 with HAP values of about 20N (16-19N) and about 40N (39-41N) that were stored for a period of three months. Reconstitution behaviour of such tablets stored for a week or up to three months was all scored with 0-1.

[0206] In conclusion, even after a prolonged storage period, all tested solid milk tablets still displayed acceptable and/or even good reconstitution behaviour, indicating the solid milk tablets of the present invention are sufficiently shelf-stable over the tested time period. Also, reconstitution behaviour did not significantly increase over the indicated time period.

Example 5: Friability Measurements on Solid Milk Tablets

[0207] The solid milk tablets of Table 3 were tested for their friability. To this end, seven tablets were placed on an AS200 sieve shaker (Retsch) equipped with a 600 μm sieve with a 200 mm diameter and 50 mm height (Retsch) and vibrated thereon for a selected time period. The weight of the tablets was determined on the sieve after selected shaking time intervals.

[0208] The method was carried out as follows: weighing of the empty sieve, placing of seven tablets on the sieve, weighing the total of the sieve with the tablets, placing the sieve on an aluminium pan with a 200 mm diameter (Retsch) and into the sieve shaker, clamping the lid on top of the pan sieve stack which consisted of the sieve and aluminium pan, setting the sieve shaker amplitude to 1.0 mm/“g” and a time of 2 minutes. After the machine finished shaking, the sieve with the tablets was weighted. At this time point, the fraction of powder that had come of the tablets was determined using the following equation: (initial mass of the solids−mass of the solids after the test)/initial mass of the solids×100%.

Results

[0209] Solid milk tablets of Table 3 with a preselected hardness after press (20N, 30N, 40N or 50N) to which a preselected amount of moisture was added (20 mg, 30 mg, 40 mg or 50 mg) were tested with the above-mentioned friability test method. From the results presented, it is clear that all tested tablets have a friability that lies below 5% under these test conditions. Friability results of the tablets to which 30 mg and 40 mg water was added are not shown but give values that are intermediate with respect to the 20 mg and 50 mg tablets.

[0210] A range of representative solid milk tablets obtained by the method as mentioned in WO2012/1099472 A1 were tested for friability with the herein mentioned method. These tablets had a friability score of between 10.5% and 21.2%.

TABLE-US-00004 TABLE 4 Friability measurements of a representative set of solid milk tablets Sample Friability (%) 20 N/20 mg 3.4 20 N/50 mg 0.2 30 N/20 mg 1.6 30 N/50 mg 0.2 40 N/20 mg 1.5 40 N/50 mg 0.1 50 N/20 mg 0.6 50 N/50 mg 0.1 Note: Sample 20 N/20 mg, for instance, refers to a solid milk tablet that has been produced with a compression ratio that yields a solid milk unit with a H.A.P. value of about 20 N which absorbed an amount of 20 mg water during the humidification step.

[0211] Friability is an important characteristic of milk tablets since it is desirable to produce solid milk tablets that are still intact at the time the consumer wishes to use them for preparing liquid infant formula. It is not only unattractive for the consumer to open a package of tablets and finding a layer of powdered milk inside the packaging, but use of friable tablets may also lead to under-feeding of an infant since the prescribed amount of infant formula would not be used. It is considered that a friability level of less than 5% in the herein given test is more than an acceptable score that allows tablets to arrive at the consumer in a proper state without too much worn-off powder being present on the bottom of the package. Notably, solid milk tablets that absorbed 20 mg water (which equates to less than 0.5 wt % of the solid milk tablet) displayed very good friability scores, especially with higher preselected HAP settings.

[0212] In conclusion, hardness/mechanical strength as well as friability, reconstitution and tablet shelf-life were all considered to be good for the solid milk tablets obtained via the method of the present invention.

Example 6: SEM Pictures and Surface Porosity

[0213] When tablets are made from infant milk formulae total porosity thereof can be measured by determining the apparent density and the real density (such as by using a stereopyncometer). In an attempt to better explain tablet reconstitution, surface porosity of the solid milk units was determined. Said method will give a value for the amount of surface pores were water can easily penetrate and thus promote reconstitution of a tablet. Briefly, the method involves making scanning electron microscope pictures of a tablet surface and calculating the percentage of pore openings in the tablet surface.

[0214] The outer surface of solid milk tablets mentioned in Table 3 were prepared for SEM analysis by carefully cutting tablets in pieces and selecting suitable tablet crust parts for analysis of the outer surface thereof. Crust parts were stuck to a suitable SEM stub and gold coated to allow for SEM imaging using a SEM JEOL JSM-5610. Sharp SEM pictures of good quality were obtained using a 70× magnification. The obtained pictures were saved in a TIFF file format for further software processing.

[0215] For further software processing, the ImageJ software suite 1.46R (freeware made available by the National Institute of Health of the USA) was used as follows. Appropriate tablet surface images were loaded in ImageJ. Under “Image” the threshold was adjusted in such a way that pores and solid tablet surface were clearly separated. Under “Analyze”, “Measure” was chosen after which a resulting tablet is shown in a binary, black and white image. After that, the area value was recorded which represents the percentage of pores of the analysed surface, i.e. surface porosity (in %).

[0216] Using this procedure, a clear and reproducible distinction could be made between surface pores (holes, represented by black regions) and the solidified surface of the tablets (represented by white regions). The results show that the solid milk tablets obtained by the method of the present invention have a surface porosity of between 6% and 21%.

TABLE-US-00005 TABLE 5 Surface porosity data. Amount of Hardness After Press water added 20 N 30 N 40 N 50 N 20 mg 17 15 21 17 30 mg 15 15 13 12 40 mg 10 13 6 10 50 mg 11 8 6 7

[0217] Using the herein mentioned method, the surface porosity of the tablet surface depicted in FIG. 2 of WO2012/1099472 A1 was determined as a reference. The surface porosity thereof was determined to be 5%.

Example 7: Colour Measurements on Solid Milk Units

[0218] The YI E313 yellow index, which is a standard index used for determining yellow surface coloration, was used for determining the white/yellow coloration of the solid milk tablets of Table 3. The yellow index runs from 0 to 100, where 0 corresponds to white and 100 to yellow. Solid milk tablets were placed in a Minolta Chroma Meter CR-410, equipped with a D65 light source. For each measurement, nine tablets were positioned next to each other in a 3×3 rectangular fashion to produce one sufficiently large, continuous rectangular surface that allows making colour measurements with the equipment set-up. Before the samples were measured, the device was calibrated with a white calibration tile (S.No. 17333015 D65 (Y 92.7, x 0.3150, y 0.3208)) to obtain absolute colour values.

[0219] Next, the Chroma Meter was placed on top of the continuous, rectangular solid milk tablet surface and three colour measurements were made per individual sample, as the machine gives off three flashes when the trigger is pulled. Average results are presented in Table 6. Results showed that there appears to be a trend in the sense that all tablets all had a coloration of below 32.97, with coloration increasing with increased water addition.

TABLE-US-00006 TABLE 6 White-yellow coloration of solid milk tablets according to the present invention. Amount of Hardness After Press water added 20 N 30 N 40 N 50 N 20 mg 24.89 28.01 28.44 28.78 30 mg 27.28 28.37 29.63 27.25 40 mg 29.22 29.27 30.87 29.48 50 mg 31.95 32.97 30.69 30.06

[0220] In contrast to the results presented in Table 6, the YI E313 yellow index of commercially available solid milk tablets from Meiji (stage 0, Hohoemi Cubes with the following macronutrients per 100 g; 11.8 g protein, 25.9 g fat and 57.2 g carbohydrates) was determined at 44.08 which is a much more yellow coloration than any of the solid milk tablets of Table 6. Results were confirmed by visual observations for other solid milk tablets as obtained.

[0221] The macronutrient profile (expressed as g/100 g tablet) of the solid milk tablets according to the invention is very similar to the tested Meiji tablets with 9.3 g protein, 20.6 g fat and 59.3 g carbohydrates. Solid milk tablets with a different but yet again comparable macronutrient profile (9.7 g protein, 24.7 g fat and 53.8 g carbohydrates, expressed as g/100 g tablet) obtained with the compacting, humidifying and drying steps of the present invention had a whiteness similar to the results shown in Table 6 (results not shown).

[0222] Thus, surprisingly the method of the present invention allows the preparation of solid milk tablets that are less yellow than currently marketed solid milk tablets. As white coloration is seen as an important sensorial quality parameter of milk by consumers, the milk tablets according to the present invention are considered more attractive for the consumer than more yellow solid milks.