Binding agent dispersible in hot water

A process for producing a roux-like binding agent for foodstuffs. Fine particles of farinaceous material are transported into an enclosed particle coating zone where a molten, high-melting point fat is sprayed, in the form of fine droplets, onto the particles to coat them. At the same time, the coated particles are cooled to a temperature below the melting point of the fat using chilled gas. The coated particles are flowable and disperse readily in hot water.

This invention relates to a binding agent for foodstuffs which is 
dispersible in hot water. The invention also relates to a process for 
production of the binding agent. 
BACKGROUND ART 
Binding agents or, as they are sometimes known, thickeners form the base of 
many dried food products such as sauces, soups and gravies. These dried 
food products usually contain other ingredients such as dried vegetables, 
meat extracts, yeast extracts, sugars, salt, fats, oils and the like but 
it is the binding agent that usually gives the food, once re-hydrated, its 
consistency and creamy sensory appeal. The idea is for the binding agent 
to simulate the roux used in traditional cooking. 
Like roux, the binding agents are usually prepared from a starch material 
and a fat. The starch material is usually in the form of a flour of some 
sort; particularly wheat flour although other flours are used. Now-a-days 
the fat is usually a hardened vegetable fat. The starch material and the 
fat are combined, often dehydrated, and then added to the remaining 
ingredients of the dried food product. However, severe problems have 
arisen in providing a binding agent which, when hot water is stirred into 
the dried food product, does not result in lumping or clumping. If the 
product is intended as an "instant food", it is important that the dried 
food product re-hydrate rapidly upon the addition of hot water without 
lumping or clumping. 
The problem was addressed in U.S. Pat. No. 4,363,824. This patent describes 
a process in which a high melting point fat is first heated to above its 
melting point (for example to 70.degree. C.). A flour is then mixed in to 
provide a dough containing about 55% to 80% flour. The dough is then 
transported to a cooling tank where it is allowed to cool under controlled 
conditions. In particular, the dough undergoes cooling so that a constant 
temperature decrease occurs at least while the dough is at a temperature 
between 35.degree. C. and 15.degree. C. Cooling in this manner causes the 
fats to undergo crystal structure modifications and results in a product 
which contains less than 50% liquid fat when at a temperature of 20 to 
35.degree. C. The cooled dough is then run through a cooling roller to 
form it into a thin sheet. The dough is then scraped off in the form of 
flakes. The flakes are then added to dried foodstuffs as the binding 
agent. The binding agents produced by this process provide the dried 
foodstuffs with good re-hydration properties. However, the binding agents 
contain relatively high amounts of fatty material in order for them to be 
processed through the cooling roller. In certain cases, for example if the 
binding agent is to be used for low fat products, this may be 
disadvantageous. 
Another approach is described in U.S. Pat. No. 4,568,551. This patent 
describes a process in which a high melting point fat is heated to melt it 
and the melt is then mixed with a starch material, particularly wheat 
flour, to form a homogeneous dough. A small amount of water is then mixed 
in. The dough is then heated to a temperature above 90.degree. C. and 
maintained at the elevated temperature, under continuous mixing, until the 
moisture content reduces to below 7%. The dough is then cooled to room 
temperature and ground up to form a free-flowing, dehydrated, binding 
agent. The binding agent is described to disperse readily in boiling water 
without the formation of lumps. The disadvantage of this process is that 
it requires heating to above 90.degree. C., in many cases for long 
periods. This makes the process expensive. 
Yet another process is described in British patent 1478843. In the process 
described in this patent, an agglomerated starch is coated with an edible 
fat of high melting point in a planetary mixer or bowl chopper. The 
process has the advantage of being simple and no heating or cooling is 
required. Also the fat content of the binding agent may be low; for 
example about 20% by weight. However the binding agent is not made up of 
well formed particles and the flowability of the binding agent is low. 
Therefore there is a need for a binding agent for foodstuffs which is 
flowable, readily dispersible in water, which may contain relatively low 
amounts of fatty materials, and which may be produced by a process not 
requiring the use of high temperatures. 
SUMMARY OF THE INVENTION 
Accordingly, in one aspect, this invention provides a process for producing 
a binding agent for foodstuffs, the process comprising: 
introducing chilled gas at a temperature below 10.degree. C. upwardly into 
an enclosed particle coating zone to chili particles of farinaceous 
material transported in the enclosed particle coating zone, the particles 
of farinaceous material having a size less than 500 .mu.m; 
spraying a molten, edible fat of melting point above 35.degree. C. into the 
particle coating zone in the form of droplets of size less than about 80 
.mu.m to coat the particles of farinaceous material and provide coated 
particles comprising about 60% to about 85% by weight of farinaceous 
material and about 40% to about 15% by weight of edible fat, the chilled 
gas cooling the edible fat which coats the coated particles to a 
temperature below the melting point of the edible fat; and 
collecting the coated particles. 
The process surprisingly produces a binding agent which is readily 
dispersible in hot water without clumping and which provides excellent 
texture and consistency. For example, in tests the binding agent dissolved 
within 20 seconds in hot water. Further, the binding agent may have a low 
fat content; for example as low as 15% by weight. Also, the coated 
particles of the binding agent are substantially spherical and flowable. 
Consequently, an excellent binding agent for powdered, dry foodstuffs is 
provided. 
The amount of fat sprayed into the particle coating zone is preferably 
sufficient so that the coated particles contain about 20% to about 40% by 
weight of fat and about 80% to about 60% by weight of farinaceous 
material. The farinaceous material preferably contains at least 50% by 
weight of a flour; particularly a wheat flour. However, other flours may 
be used and examples are rice flour, cassava flour, tapioca flour and the 
like. Also, agglomerated starches such as potato starch, maize starch, 
wheat starch and the like may be used in combination with the flour. 
Preferably, the particles of farinaceous material have a particle size of 
less than 300 .mu.m. It is especially preferred if less than 25% by weight 
of the particles of farinaceous material have a particle size less than 
about 50 .mu.m and less than 5% by weight have a particle size greater 
than about 200 .mu.m. It is also preferred if the distribution of 
particles sizes is relatively small; for example at least 60% by mass of 
the particles having a particle size within about 60 .mu.m of the mean 
particle size. Preferably about 70% by mass of the particles have a 
particle size in the range of about 80 .mu.m to about 150 .mu.m. The mean 
particle size is preferably about 100 .mu.m. 
The edible fat preferably has a melting point in the range of 35.degree. C. 
to 50.degree. C. It is particularly preferred for the melting point of the 
edible fat to be in the range of 40.degree. C. to 45.degree. C. 
The molten fat sprayed into the particle coating zone preferably has 
droplet sizes of about 5 .mu.m to about 80 .mu.m. More preferably, the 
droplet sizes are about 5 .mu.m to about 40 .mu.m. 
Prior to being sprayed into particle coating zone, the edible fat is heated 
to above its melting point. Preferably, the fat is heated to a temperature 
no more than 10 to 20.degree. C. above its melting point For example, a 
fat which has a melting point in the range of 40.degree. C. to 45.degree. 
C. may be heated to about 55 to 60.degree. C. 
The coated particles are preferably cooled to a temperature at least 
20.degree. C. below the melting point of the fat. For example, the coated 
particles may be cooled to a temperature of less than about 15.degree. C., 
preferably between about 0.degree. C. and about 10.degree. C. 
In one embodiment, the particles of farinaceous material fall through the 
particle coating zone against the flow of the chilled gas. Then the molten 
fat may be sprayed into, and towards the centre of, the stream of falling 
particles of farinaceous material. Preferably, the spray is directed 
substantially perpendicular to the stream of particles of farinaceous 
material. 
In this embodiment, the flow rate of the chilled gas is preferably 
insufficient to completely fluidize the coated particles and prevent them 
from falling from the particle coating zone. However, the flow rate of the 
chilled gas is preferably selected so that the residence time of the 
particles in the particle coating zone is less than about 5 minutes; more 
preferably less than 2 minutes, for example about 1 minute. Too long a 
residence time in the coating zone will result in particles which carry 
large quantities of fat. Also the particle size of the coated particles 
will become too large. On the other hand, too short a residence time in 
the coating zone will result in the coated particles carrying too little 
fat to give the desired consistency in the food product ultimately 
produced. Also, too little chilled gas will not give the required cooling. 
However, the flow rate of the chilled gas may be adjusted as desired to 
give a desired coating to the particles. The flow rate of chilled gas 
required will depend upon numerous parameters such as the temperature of 
the chilled gas, the temperature of the molten fat, the flow rate of the 
coated particles, the cross-sectional area for flow, the particle size, 
and the like. However, a suitable flow rate is readily determined by the 
person skilled in the art. 
In another embodiment, the particles of farinaceous material may be 
fluidized by the chilled air. This embodiment is particularly suited to a 
batch process. Preferably, the molten fat is sprayed into the bed of 
fluidized particles over a time of 20 minutes or less; for example about 
15 minutes. Upon completion of spraying of the molten fat, the particles 
may be fluidized for a further period to further chill the coated 
particles. 
Preferably, the coated particles have a particle size in the range of 100 
.mu.m to about 700 .mu.m, for example about 200 .mu.m to about 500 .mu.m. 
The chilled gas is preferably air since this will usually be the least 
expensive gas; but any suitable gas may be used such as carbon dioxide and 
nitrogen. The air is preferably chilled to a temperature less than about 
10.degree. C., for example between -20.degree. C. and about 6.degree. C., 
prior to introduction into the particle coating zone. 
Upon removal from the coating zone, the coated particles may be stored at a 
temperature between 0.degree. C. and 15.degree. C. to permit the fat in 
the coating to convert to the .gamma. crystalline form. It is usually 
found that the fat which initially solidifies on the particles, does so in 
the unstable .alpha. crystalline. If the fat is stored at a temperature of 
less than about 15.degree. C. for up to 72 hours, the crystalline form 
first converts to the .beta. crystalline form and then the stable .gamma. 
crystalline form. 
In another aspect this invention provides a binding agent for foodstuffs 
produced by a process as defined above, the binding agent comprising 
coated particles each having a core of a farinaceous material and a 
coating of an edible fat; the coated particles having a particle size of 
about 200 .mu.m to about 500 .mu.m and being dispersible in hot water. 
In another aspect this invention provides a flowable binding agent 
comprising substantially spherical particles each having a core of a 
farinaceous material and a coating of an edible fat, the edible fat 
comprising about 15% to about 40% by weight of the binding agent and the 
farinaceous material comprising about 85% to about 60% of the binding 
agent, and the coated particles having a size of about 200 .mu.m to about 
500 .mu.m and being dispersible in hot water. 
Preferably about 70% by weight of the farinaceous material making up the 
core of the coated particles has a particle size in the range of about 80 
.mu.m to about 150 .mu.m. The mean particle size is preferably about 100 
.mu.m.

EXAMPLES 
The following non-limiting examples demonstrates the advantages of the 
invention. 
EXAMPLE 1 
A cattle food agglomerator obtained from the Babcock company, which has an 
internal diameter of 3 meters in the lower portion 28 of the tower 2, is 
used. The tower has thirty six injector nozzles 24 positioned 
circumferentially around the injector portion 22. Wheat flour of particle 
size in the range of about 50 .mu.m to about 200 .mu.m, with about 70% by 
mass of the particles having a particle size in the range of about 80 
.mu.m to about 150 .mu.m and with the mean particle size being about 100 
.mu.m, is fed into the tower 2 at a rate of 3.6 metric tons/hour. An air 
flow of 2400 m.sup.3 /h is used to transport the flour particles to the 
tower 2. 
Molten hydrogenated palm oil fat (type 44 obtained from Crocklaan which has 
a melting point of about 45.degree. C.) at a temperature of 55 to 
60.degree. C. is pumped at a pressure of 35 bars through the injector 
nozzles 24 into the tower 2. The average droplet size of the fat sprayed 
into the tower 2 is about 30 .mu.m. 
Chilled air, at a temperature of -20.degree. C. is blown into the gas inlet 
32 at a flow rate of 14000 m.sup.3 /hour. The flour particles have a 
residence time in the coating zone of about 1 minute and then fall through 
the particle outlet 36. The coated particles leaving the tower 2 have a 
particle size in the range of 200 .mu.m to about 500 .mu.m and comprise 
about 36% fat by weight. 
The coated particles are collected and stored at 10.degree. C. for 72 
hours. The coated particles obtained are substantially spherical and flow 
easily. 
EXAMPLE 2 
80 g of coated particles obtained from the process of example 1 and 
comprising 36% fat and 64% flour are added to 1 liter of boiling water 
while stirring. The particles dissolve rapidly, in about 20 seconds, 
without lumping or clumping. The resulting solution has a viscosity of 150 
mPa.s at 100s.sup.-1 and 100 mPa.s at 300s.sup.-1 which corresponds to a 
sauce of average consistency. The solution also appears to be smooth and 
creamy. 
EXAMPLE 3 
An Aeromatic fluidized bed agglomerator is used. A charge of 2.25 kg of 
wheat flour is placed in the agglomerator on the bed grill. The wheat 
flour has a particle size distribution such that less than 25% by weight 
of the particles have a size of less than about 50 .mu.m and less than 5% 
by weight have a size of greater than about 200 .mu.m. The particles have 
a mean particle size of about 100 .mu.m. Air is cycled through the 
agglomerator at a flow rate sufficient to fluidize the bed of wheat flour 
particles. The air entering the bed is at a temperature of about 6.degree. 
C. Air leaving the agglomerator is chilled to about 6.degree. C. and 
recycled back to the agglomerator. 
A charge of 1.26 kg of molten hydrogenated palm oil fat (type 44 obtained 
from Crocklaan which has a melting point of about 45.degree. C.) at a 
temperature of about 60.degree. C. is pumped at a pressure of 2.5 bars 
through injector nozzles into the agglomerator. The droplet size of the 
fat sprayed into the agglomerator is about 30 .mu.m. The fat is sprayed 
into the agglomerator over a time of about 15 minutes. 
After the spraying of the fat has terminated, cycling of the chilled air 
through the agglomerator continues for another 3 to 6 minutes. The cycling 
of the chilled air is then terminated and the coated particles are 
collected from the agglomerator. The coated particles have a particle size 
in the range of 200 .mu.m to about 500 .mu.m and comprise about 36% fat by 
weight. The coated particles are stored at 4.degree. C. for 24 hours. The 
coated particles obtained are substantially spherical and flow easily. 
80 g of the coated particles are added to 1 liter of boiling water while 
stirring. The particles dissolve rapidly, in about 20 seconds, without 
lumping or clumping. The resulting solution has a viscosity which 
corresponds to a sauce of average consistency. The solution also appears 
to be smooth and creamy. 
EXAMPLE 4 
The process of example 3 is repeated except that 0.75 kg of molten 
hydrogenated palm oil fat is sprayed on the wheat particles. The coated 
particles obtained have a particle size in the range of 200 .mu.m to about 
500 .mu.m, are substantially spherical and flow easily, and comprise about 
25% fat by weight.