CA1058947A

CA1058947A - Methods of producing dry pulverulent foodstuffs or animal foods and products produced according to the methods

Info

Publication number: CA1058947A
Application number: CA221,055A
Authority: CA
Inventors: Oskar W. Andersson; Bengt A. Nilsson
Original assignee: MILKFOOD AB
Current assignee: MILKFOOD AB
Priority date: 1974-02-27
Filing date: 1975-02-26
Publication date: 1979-07-24
Also published as: GB1492866A; FR2261714A1; DE2508192B2; SE403035B; DE2508192C3; NL7502308A; DE2508192A1; SE7402583L; FR2261714B1

Abstract

CANADIAN PATENT APPLICATION
OF
OSKAR WILHELM ANDERSSON
and BENGT AKE NILSSON
FOR
METHOD OF PRODUCING A DRY PULVERULENT FOODSTUFF OR ANIMAL FOOD
AND A PRODUCT PRODUCED ACCORDING TO THE METHOD.
Abstract of the Disclosure.
An emulsion of fat in a proteinaceous liquid is produced and applied to a granular carrier, whereupon drying takes place at 50-200°C. The product comprises granules of a layered struc-ture which includes an inner core with discrete fat globules on the surface surrounded by an outer protein layer. In mashed-potato powder, for example, the core consists of mashed-potato flakes, the fat of cured sunflower oil and the protein layer of dried skimmed milk.

Description

1~8947 The present invention relates to a method of producing a pulverulent foodstuff or animal food and to a product produced according to the method which product is ready for use after mixing with a liquid such as water. The invention relates par-,~ , ~ , " .
ticularly to the production of so-called whole mashed-potato powder or mix, gruel powder, soup powder, grav~ powder, nutri-tive powder and blancmange powder, which are ready for use after the addition of hot or cold water and stirring. The expression "powder" in this context is intended to include particulate ma-terial with both irregular and regular particles, that is to say, both flake-formed material and material having substantially ~
round granules. ~ ~;
Such products comprise different component parts, such as protein, fat, carbohydrates, flavourings and additivesj such as sugar, salt and spices.
It is previously known to produce such products by dry-mixing the~different component parts. However, such a process involves considerable disadvantages: first and foremos-t poor dispersibility on the addition of liquid, and separation of the di~ferent dry, pulverulent component parts during transport and~ storage so that the product becomes lnhomogeneous. Attempts have been made to avoid these disadvantages bv wetting the `
~ , powder mixture with, ~or example, steam or finely divided ~ ~ water, and to create cohesive granules or agglomerates con-i: , taininy the differént component parts, by drying.~ In, for ~ example, the production of whole mashed-potato powder solely PH/1m from mashed-potato powder or flakes and powdered milk, this ' ` ' ' . ' ~ ~

.~ 89~7 involves, however, a deterioration in the quality of the powdered milk because of the moisture and heat treatment. ~lso, the mechanical mixing required to produce the powder mixture itself entails disadvan-tages in that the flakes or granules are subjected to mechanical abrasion, so that the cells in, for example, mashed-potato flakes are damaged. This will release an increased arnount of starch in the subsequent preparation by the addition of water, with the result that the mashed potatoes become pasty. In another prior art process for the production of mashed potatoes, liquid fat is applied to the potato granules or flakes, and the remaining solid componen-t parts, i.e.
powdered milk, salt and spices are admixed, the fat acting as a binder and retaining the other component parts on the potato '.' granules or flakes. A disadvantage with this process is that the addition of a great amount of fat i5 required (up to approxi-mately 40%~ and, furthermore, the product does not have the optimum wettability and dispers:ibility because the fat surrounds the potato granules or flakes as a protective membrane. More-over, the fat itself i5 unprotected and is, therefore, sensitive to oxidation because of exposure to air.

. , ~ The present invention has for its object to obviate the i above-mentioned disadvantages and to produce a pulverulent .~ .
foodstuff or animal food consisting of agglomerates of the different component parts thereof, which agylomerates can be described as being of lay~red structure, en-tailing that the ' ~ product does not separate or deteriorate in any other way on storaye, bu-t is stable during s-torage and has the optimum ''~ , ' ' '', :

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dispersibility and restorability when it is prepared for use by the addition of a liquid. These ob~ects and the advantages gained thereby are realized by mixing and homogenizing a liquid component comprising fat, a proteinaceous liquid, pre-~erably skimmed milk, and an emulsifier, to form an emulsion which, po.ssibly after the addition of further proteinaceous or carbohydrate-containing material, is atomized and applied to a solid component and dried at a temperature of Erom 50-200C, the fat emulsified in the emulsion being deposited on the solid , component as small globules and surrounded by a dried layer of the proteinaceous continuous phase of the emulsion, and by then ;
cooling the dry product.
secause the fat, on application to the solid component, is in an emulsified state in the proteinaceous liquid (skimmed .
milk) the drying operation will provide a layered product in -~
which the different component parts are arranged in a determined order and in which the solid component constitutes a core sur~
rounded by the fat o~ the applied emulsion, the fat heing, in its turn, surrounded by the dried proteinaceous liquid (skimmed milk). By dividing the solid component into different component . ,, ^~ parts and successively adding them in the drying operation, ~i other layered structures can be obtained.
`i ~ Because the Eat in the above-mentioned layered structure `' is surrounded by a pro-tec-tive layer of the dried proteinaceous liquid (skimmed milk) the finished product will be less sensi-tive to oxidatlon by the action of air. Since, at the same time, the ~atty layer surrounding the core is not coherent, but con-., ', "'' ' : .' ~, ! ' ., . , : , I . .
., ' ,' ' ' ' . ' ", ' ' ' ' ~ , ' ~58~ 7 sis-ts of the ~iscrete fat glo~ules from the emulsion, an optimum dispersibility and restorability is ob-tained on the addition of liyuid, since said liqui~ can without difficulty penetrate to the cores of the agglomerate.
For a better understanding of the invention, specifically preferred er~odiments will be described hereinbelow, in an illustrative but not 11mitative manner, by way of example and with reference to the accompanying drawings in which:
Fig, 1 shows a preferred apparatus for -the production of the pulverulent foodstuff hy spray-drying;
Fig. 2 shows another emobdiment for the production of the -pulverulent foodstuff, utilizing a fluidised bed; and Fig. 3 shows a further embodiment for the production of mashed-potato flakes, using a drum dryer.

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Preparation of whole mashed--potato powder in flake form hy spray-drying.

` In this Example, use was made of a pil~t plant scale .spray-. dryer of -the cons-truction schematically shown in Fig. 1. The , - . . .
uid componen-t comprised-an emulsion o skir~ned milk, cured sunElo~er oil and an emul~ifier consisting of glyceryl mono-stearate. The solid componellt was mashed-potato flakes.
The skimmed milk emulsion was preparQd by concentrating the skimmed milk to a dry content of approximately 40~. Subsequently, : : ~
the fat and the emulsifier were admixed to the concentrated skimmed milk in such an amount that the weight ratio of the skimmed milk to the Eat plus the emulsifier amounted to 2~

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';' : .~, ' ,': ''' ' ' The resulting mixture was -then treated in a homogenizer so as to form an emulsion, the size of the emulsified fat globules being pre~erably 1-2 microns. The finished emulsion which thus made up the liquid componen-t was fed through a conduit 1 to a spray-drying tower 2. In the drawing, the conduit 1 is connected to another conduit 3 which is intended for the introduction into .... ~
the emulsion, if desired, oE ~urther proteinaceous or car~ohydrate-containiny material, such as tomato puree, yeast, or dried or suspended cocoa powder. The emulsion fed into the spray-drying tower was atomized by a centrifugal spraying nozzle 4 located in the upper xegion of the spray-drying tower. The solid compo- ~
nent which, as stated above, comprised mashed-potato flakes, ~ -was fed via a funnel 5 to a conveyer-type weighing machine 6 and a conduit 7 to a distributor 8 located below the centrifugal spraying nozzle 4. The emulsion and the flakes were introduced .
; into arddistributed in the spray-drving tower by means of the ;I centrifugal spraying nozzle ~ and the distribu-tor 8, respectively,~
s ' J~ the flakes being brought into con-tact with the a-tomi2ed emulsion ... .
and coated with an adhering layer thereofr At the same time, drying air having a temperature o~ approximately 70C was in-troduced into the spray-drying tower through supplv means (not shown). ~s the formed agglomerates of flakes and emulsion fell towards the lower region of the spray-dryer tower 2, they wexe dried by the drying air so that the liquid emulsion Eormed a dried coating on the surface of the Elakes.
In -the spray-drying to~,ler treatment, the water evaporation amounted to approximately 10 kg/h. The supplied emulsion flow ., .
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., amounted to approximately lS0 y/min while the flow of the mashed-potato flakes was approximately 34~ g/min. As mentioned above, the temperature oE the drying air was 70C while the temperature of the exhaust air was 35C.
After the ahove deiscribed treatment in the spray-drying tower the warm agglomerates thus Pormecl were discharged from the lower region of the tower. The agglomerates were not com-pletely dry, but displayed a certain residual moisture content.
For complete drying, the agglomerates were fed into a fluidised .~ .
bed device for after-drying and cooling.
As shown in Fig. 1, the fluidised bed device 9 included an elongated horizontal container lO fitted with supply means ll ~
, ~ .
for the updraught supply of a fluidising gas, preferably air, as indicated by the arri~ws 12. A grid or ne-t bottom 13 was located inside the container lO and formed a base for the -~
fluidised bed. T~hen the agglomerates formed in the spray-drying~
tower were fed into the container lO they deposited on the net 13 and formed a bed which was fluidised by the fluidising gas 12. Warm drying air at a temperature of 40C was introduced through the first supply means 11, and suhsequently, when com~
plete drying had taken place, cold air was introduced through the remaining supply means to cool the agglomerates. Possible powder dus-t or "fines" formed during the process were recycled for renewed treatment via a conduit 14. The cooled agglomerates~ `~
were then ready for packing and storing or sale. It should be mentioned that the solid component in the above example can also include further componen-t parts, such as dried vegetables.

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~` ~0~3~L7 Study of the agglomerates produced in -the above manner showed that they comprlsed an inner core of flakes surrounded by distirnct small ylobules of fat fxom the emulsion, which in their turn, were surrounded by a layer of dried skimmed milk.
Owing to this construction the fat is protected from air oxida-tion by the surrounding layer o~ dried skimmed milk, at the same time as the construction of the fat layer in the form of distinct small gl.obules allows water to penetrate to the core, for which reason very good di~persibility and restorahility were obtained when water was subsequently added.
The above described atomiza-tion oE the liquid component will lead to a very large magnification of the surface thereof and thus to a highly increased effect of the drying gas. From the purely theoretical point of view, this surface magnification w~ill take place as the atomized llquid component, on contact with the solid component, for example, mashed potato flakes, is distrlbuted in a thin layer onto the surface of the flakes and thereby undergoes a further surface magnificati.on. By this ;
. surface magniication the evaporation o the liquid at main-tained temperature will be greatly increased. Alternatively, the amount of evaporated liquid per unit of time can be main~
.. -~ tained unchanged by loweriny -the temperature. In the former case an increased production is obtained, and in the latter case a ;.
more gentl.e treatment, which is impoxtant whenever temperature-'J, sensiti.ve products are concerned. The above reasoning can he :;, .. ~ . exemplified hy the low temperature (70C)of the in-flo~.~ing drying air in Exar~le 1 above. This temperature should be compared with ' '' ' ' , : . , : : -' s : .
:, , ~ ':, '' ' . ' ', , , ~ :' the temperature normally used in spray-drying, i.e. approximately 180C. Generally, the temperature of the supplied drying gas should lie between 50C and 200C, preferably be-tween 60C and 180C. ~ particularly delicate drying treatment is obtained if the temperature of the supplied air is maintained at 70-80C, which is advantageous in the drying of sensitive products. It ?
should, however, ~e pointcd out that it is difficult to state any specific temperature for different foodstuffs, since the above temperature can be varied dependent on various fac-tors, such as production, quality, etc., by altering the process parameters, such as the in-flow of the liquid componen-t, the solid component, the drying air etc.
It is obvious that the type and location of the supply means for the emulsion and the powder, as described and shown in Example 1, are not the only conceivable ones, other types - -and locations being also possible. Thus, the introduction of :~
the powder can take place in the centrifugal sprayer, at the periphery of the chal~er tangentially to the chamber wall, and in the upper region of the spray-drying tower, at the periphery ~ of the chamber in a direction towards the sprayer, or at -tlle i outlet of the spray-drying tower. Cor~inations of these introduc-. : , tion variations are also possible, so -that, for example, when ~ the solid powder component is made up of several different com~
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ponent parts, such as mashed-potato flakes, salt and spices, these cornponent parts can be introduced into the spray-drying tower at clifferent locations. Even if the solid powder component is made up of one compollent part only, such as mashed-potato ~ -1~, 9 ,' ~, ' .

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1~58~L7 flakes, it is likewise possible to divide up this component into several parts and introduce them at different locations : , .
into the spray-drying tower in order therehy to achieve an altered structure of the agglomerates formed. The essential feature which must be taken into account in every case is that a good contact between the liquid and the solid components must be guaranteecl, that is to saV, the liquid component and the solid component must be brought together before the liquid com-ponent has ~ecome too dry to adhere to the surface of the solid component.
X~MPLE 2 J Production of nutrier.t ~owder.
In this Exam~le, a nutrient powder, suitahle for use as a ::
;~ complete diet for the inirm, ~as produced utilizin~ a full-. ~ . .
`~ scale plant of the type described in Example 1. The liquid 1~ component was an emulsion of sunflower oil in skimmed milk, i' while the solid component was sodium caseinate, soya protein, - egg white, maltodextrine, vitamins and mineral substances. The evaporation capacity of the spray-drying tower amounted to .,.! :
approximately 500 kg of water per hour. The solids content of the emulsion was approximately 45~ and the emulsion in-flow into the spray-drying tower was controlled at 310 kg/h. The in-flo~1 , of the solid component was controlled at 600 kg/h. The tempera-ture of the supplied drying air was measured at 135-140C, while :i ~ the temperature of the exhaust air was approximately 30C.
~; After trea-tment in the spray-dryin~ tower, the treatmen~t in the fluidised bed device was performed according to Example 1, ;

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. a certain after-drying heing first carried out with fluidising air at room temperature, followed by cooliny with fluidis.ing air which had been cooled over iced water.
. T.he powder produced was easily dispersible in warm or cold water.
..
~` E~AMRLE 3 Production of milk nutrient for calves.
In this Example, milk nutrient for calves was produced, utilizing the apparatus of Example 2. The liquid component was .` skimmed milk, lard, tallow, coconut oil and lecithin, while the ?' solid component was skimmed milk powder, ~hey powder, soya meal, mineral substances, vitamins and antibiotics. The evaporation ~.
capacity of the spray-drying tower amounted to approximately :.,S
'~ 1000 kg of water per hour. The solids content of the emulsion .`,, .': was approximately 50~ and the emulsion in-flow into the spray `~ drying tower was controlled at 1475 kg/h. The in-flow of the ~:
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1~ solid component was controlled at 770 kg/h. The temperature of . .
~ the supplied drying air was measured at 170C, while the tern-:~ perature of the exhaust air was 88C.
. ,: .
I'he treatment in -the spray-d.rying tower was followed by , after-drying and cooling in a fluidised bed device in accordance ;

~ with Example 2. If a free-running powder was.desired, a separa-.~ tion agent, such as tricalcium phosphate, was added at 15 in :. Fig. 1 and was mixed in a kno~.~n manner by means (n~t shown in . .
.
' ' :! detail). :~
~ The product obtai.ned was excellently suited as a mil]c ~, -i nutrient for calves.

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Production of cream substltute powder.
In this Example, cream substitute powder was produced, u~ilizing the plant described in Example 1. The liquid component was sodium caseinate, dry glucose, sugar, sodium citrate, lactose, hydroyenated soya fat, but-ter oil and water in such an amount that an emulsion with a solids conten-t of approximately 50%
~as o~tained. The solid component ~las lactose. The l;quid com-.~,' ponent and the solid component were fed into the spray-drying tower in a ratio of 10:1. The temperature of the in-flo~7ing air was 190C, while the temperature of the exhaust air was 85C.
After treatment in the spray-drying tower, the resulting product ! was cooled in the fluidised bed device shown in Fig. 1.
The product was an excellent substitute for cream in, for : example, coffee.
~; The method according to the invention has ~een described i above, in connection with the preparation of whole mashed-potato powder, nutrlent powder, milk nutrient for calves and cream sub-~ stitute powder. It will be realized, ho~Jever, that other pro-: ~ ducts can also be prepared accordingly.
Thus, gruel powder can be produced by utiliziny, as the ~;~
liquid component, an emulsion of fat and skimmed milk, in accordance with that which has been described earlier, and by . ) .
i utiliziny, as a solid component, a pasted flour of wheat, oats or barley, together with known adclitives.
i Another example is the prepara-tion of soup powder. Also in :. :
this c~se an emlllsion of fat in skimmed milk is utilized as the 12.
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-~ liquid component, in accordance with the above, while a mixture of wheat-flour, broth powder, protein hydrolysate, dehydrated ~- vegetables and meat in the form of p~/der or flakes, salt and ... other flavour and aroma substances ~ras used as the solid compo-~ nent. The SOllp powder thus prepared is easily dispersed on ... restoration in warm water.
:
:.~ Yet another example is t:he production of gravv powder such ~ as brown gravy. In thi.s case, the liquid component is an emul-:'~ sion of fa-t in skimmed milk, while the solid component comprlses ` starch derlvative, maltodextrine, milk sugar, broth powder, :s~ : soya protein, protein hydrolysate, salt and flavouring. More-over, whey is included in the composition and can be present ~: ` either in liquid form, in which case it is included in the : .
liquid component, or in po~.~7der form, in which case it is in~
cluded in the solid component. The prepared gravy powder dis-perses quickly, without lump formation, in boiling water. Thus, :
it is not necessary to stir the powder in cold water, in the ~
. ~ : conventional.way, but the gravy can be obtained by stirring .
the full amount of powder directly in boiling water. Analogous .:
with that described above, dessert powders for jellies or sauces such~:as custard, can be produced, the liquid component `- !: . ~ :
:;: comprisi.ng, ln a typical casej an emulsion of 1-15%~fat in 10-~50~ skimmed milk, while the solid component compr:ises 20-40% `.~

: sugar, 10-40% starch clerivate and aroma substances and requisite ~ additives. The powder produced is easily mlxed with cold water.

ji In Fi.g. 2 is shown an alternative embodiment of an apparatus for carrying out the method according to the invention. Also ~: ~J . ~.
., , ' : ~ ' ~ti89~7 in this case use is made of a solid component and a liquid componen-t, the liquid component comprising an emulsion of fat in a proteinaceous liquid, preferably skimmed milk. The liquid emulsion component is produced in the same way as was described above in connection ~ith Fiy. 1. The apparatus of Fig. 2 will be desaribed in connec~ion with the production of whole mashed-potato po~7der or flakes. In view oE the fact that the appara-tus corresponds substantially to the apparatus 9 with the fluidised bed in Fig. 1, the corresponding details have been given the same reference numerals.
The apparatus 16 in Fig. 2 comprises an elongated horizontal container 10, at one end 17 of which the mashed-potato powder is introduced. This powder forms a bed on the grid or ne-t 13 disposed in the container 10. This bed is fluidised by means of warm air currents 12 which are supplied by supply means 11 and are passed through khe net 13 and the bed of mashed-potato powder. In a first zone above the bed and at -the mashed-po~ato powder supply end of the container 10 are located sprayiny means 18 for applyingthe fat and skimmed milk emulsion in atomized form. The fluidised powder and the emu]sion droplets are brought .
` ~ together and form agylomerates similar to those described in ~' Example 1. At the end of said first zone an atomised solutlon of salt and spices is applied by sprayiny means 19. Alternatively, the spices can be adcled only in a sub.sequent zone, and can, moreover, be added in the form oE powder instead of solution.
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Subsequently, the agglomerates thus formed are subjected to drying by warm air :Ln a second zone o-E the container 10~ In a -- .

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third zone, the formed agglomerates are then cooled with cold fluidising air 20. '.rhe powder -thus obtained, which is the finished produet, is subsequently ready for being diseharyed through the discharye orif.iee 21. As in the apparatus of Fig. 1 a separation agent, sueh as triealeium phosphate, ean be aclded to the powder -to yive it free-runniny pxoperties. Similarly, ',1 powder dust whieh has been formed ean be recycled for renewed treatment, .in conformity with that described in connection with . Fig. 1.

~ Even if the apparatus in Fig. 2 has been deseribed with .~ referenee to the production of whole mashed-potato powder, it : ;;
.- is understood that this apparatus may be used for the produetion ~i oE other types of pulverulent foodstufEs whieh are ready for ;
use after being mixed with liquid, sueh as yruel powder, soup :- i . : -.-i powder, high value nutrient powder, yravy pbwder, dessert ~ :
powder, jellv, eustard powde:r ete. as was described above in .
;I connection with Fig. 1.
:'.1 :
:~ Aeeorcling to a further aspect of the present invention , ~ the liquid and solid components can be brought together already s ! ~ iD eonneetion with the production of the solid component, as ;~.

` will. be cleseribed here.inbelow with regard to the produetion of ~
.:~ .
i ma.shed-potato flakes.

; y ~ . Mashed-potato :Elakes arè produeed by peelin~J raw potatoes ~; -'~ 1 :
'; ~7hieh are then washed, tri.mmed, slieed, pre-eooked, cooled, boiled, pulped and dried on a drum dryer, the dry produet being , subsequently flaked. rhe modified method according to the present - .inven-tion is intencled -to be carried out in connection with the ,. , : -.' 15 : :
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. , -. - . , :: : : : : -~ drying of the pulped potato fragments on the drum dryer, as .: shown scheMatically in Fig. 3. As shown in this flgure, the L, ~ drum dryer co.mprises an interiorly heated drying drum 22 which rotates in the direc-tion indicated by an arrow. The suspension of pota-to fragments is introduced in several streams, as shown .
by means of arrows 23 and 24. The suspension applied is evened out by means of small rolls 25 and 26, so that an even layer is :: .
~ formed on the periphery of the drum. As the drum rotates ~his . .i layer is dried in that the drum is hea-ted interiorly, for example, by steam. The dried layer is removed from the drum by means of a doctor blade 27 and is then conveyed to a screw conveyor (not :.
..:
shown) to be broken up into fla]ces. According to the modified method of the invention, the liquid component i.e. an emulsion of fat and skimmed milk, is applied to the solid component, i.e. the potato, while the:latter is on the drying drum. This can suitably be done by spraying the emulsion through a nozzle 28 in atomized form against the drum between the location where -the suspension of potato fragments is applied and the location where the dried product is removed, as sho~n in Fig. 3. This er~odiment results in the advantage that the drying operation for the production of the mashed-potato flakes is also utilized for the production of the whole mashed-potato powder, in other words no further drying need be carried out in the spray-drying tower or in the fluidised bed. The economi.c advantages entailed will be readily understood.

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From the above description it is apparent -that by apply.ing .' the method o the present invention is is possible to produce

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a pulverulent foodstuff or animal food ~hich is ready for use after mixing with, for exam~le, water and displays improved propcrties with regard to nu-trient value, storage l.ife and dispersibility or restorabili-ty because of the above described particular structure of the agglomerates. While some preferred embodiments have been descrihed and shown, it is understood that modi.fications are conceivable within the spirit and scope of ~., :- the appended claims. ~
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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method for the production of a dry pulverulent foodstuff which is ready for consumption after admixture with a liquid, in which method a liquid component and an at least partially dry solid component are brought together and dried to form the desired, dry finished product, wherein the liquid component comprises fat, a proteinaceous liquid, and an emul-sifier, which are mixed and homogenised to form an emulsion which is atomized and applied to the solid component and dried at a temperature of from 50 to 200°C, the fat emulsified in the emulsion being deposited on the solid component as small globules and surrounded by a dried layer of the proteinaceous continuous phase of the emulsion, the dry product being then cooled.

2. A method as claimed in claim 1 wherein further proteinaceous or carbohydrate-containing material is added to the emulsion before it is atomized.

3. A method as claimed in claim 1, wherein the pro-teinaceous liquid is selected from at least one member of the group consisting of skimmed milk, sodium caseinate solution, isolated soya protein solution and whey.

4. A method as claimed in claim 1, wherein the pro-teinaceous liquid is concentrated to a solids content of up to 50% before being mixed with fat and emulsifier.

5. A method as claimed in claim 1, claim 2 or claim 3 wherein the solid component is mashed-potato flakes.

6. A method as claimed in claim 1, claim 2 or claim 3 wherein the solid component contains flavourings or additives.

7. A method as claimed in claim 1, claim 2 or claim 3 wherein the solid component is divided up into several portions which are incorporated during different stages of the drying operation.

8. A method as claimed in claim 1, claim 2 or claim 3, wherein use is made of soya meal, tomato puree, yeast and cocoa powder as further proteinaceous or carbohydrate-containing material.

9. A method as claimed in claim 1, claim 2 or claim 3 wherein a separating agent, is added to the cooled product.

10. A method as claimed in claim 1, wherein the mixing and drying of the liquid and solid components are carried out in a spray-drying operation by introducing into a spray-drying chamber the solid component, the liquid component which, on introduction, is atomized by means of a sprayer, and a warm, drying gas, whereafter the resulting product is discharged from said chamber , and cooled.

11. A method as claimed in claim 10 wherein the resulting product after discharge from the chamber is dried before it is cooled.

12. A method as claimed in claim 10, wherein the solid component is divided up into several portions which are introduced at different locations in the spray chamber.

13. A method as claimed in claim 10 wherein the product is after-dried by being maintained in a fluidised bed and subjected to the action of drying gas flowing through said bed.

14. A method as claimed in claim 10, claim 11 or claim 12, wherein the product is cooled by being maintained in a fluidised bed and subjected to the action of cooling gas flowing through said bed.

15. A method as claimed in claim 10, claim 11 or claim 12, wherein the drying gas introduced into the spray-drying chamber is at a temperature of 60-180°C.

16. A method as claimed in claim 10, claim 11 or claim 12, wherein the drying gas is introduced into the spray-drying chamber at a temperature of 70-80°C.

17. A method as claimed in claim 1, claim 2 or claim 3 wherein the mixing and drying of the liquid and solid components are carried out by causing the solid component to form a hori-zontal elongated fluidised bed divided into three zones, warm fluidising drying gas being passed through the first and second zones of said fluidised bed, and cold, fluidising cooling gas being passed through the third zone of said bed, the liquid emulsion being supplied, in atomized form, to the first zone, followed by at least one member of the group of flavourings and additives, in the form of an atomized solution, while final drying takes place in the second zone, the product thus obtained being subsequently cooled in the third zone.

18. A method as claimed in claim 1, claim 2 or claim 3 in which the product is mashed-potato flakes and the solid component comprises potato which, in the form of pulped fragments, is added and distributed as a layer on a rotating drying drum, said layer, after drying on said drum, being removed therefrom and broken up into flakes, wherein the bringing together of the liquid and solid components takes place by spraying the liquid component, in atomized form, against said drum.

19. A pulverulent foodstuff which is ready for consumption after admixture of liquid thereto, and is produced in accordance with claim 1 which foodstuff comprises agglomerates consisting of a core of a solid component, said core being surrounded by fat in the form of fine particles, which, in their turn, are surrounded by a dried layer of a proteinaceous liquid.

20. A pulverulent foodstuff as claimed in claim 19, wherein said dried layer of proteinaceous liquid is further supplemented with further proteinaceous or carbohydrate-containing material.