Note: Descriptions are shown in the official language in which they were submitted.
21~3~2
Method ~or the continuou~ preparation o~ a solid food
matrix
The invention concerns a method for the continuous
production of a solid food matrix having a moisture content
of between 35 and 75%, from a liquid mixture based on
blood, lipid and water, in which the said mixture is
homogenized and subjected to heat treatment.
A method for preparing attractive reformed chunks in a
continuous process is already known. Patent EP 265740
concerns a method for the preparation of pieces by mixing a
meat base in an aqueous medium. This method cannot however
be transposed for the treatment of a liquid based on blood
and lipid, since it would in no way allow solid chunks to
be obtained. Patent FR 2343431 previously concerned a
method for the preparation of a food based on blood and
lipid for the preparation of chunks resembling liver. The
disadvantages of this method are that it is not possible to
operate continuously, that a reducing sugar is used and
that neither a light coloured gel, nor a gel with a texture
firm enough to be cut while still hot is obtained without
the excessive formation of fines but a food matrix which is
friable and easily broken.
Patent FR 24179~7 concerns a method for decolorizing blood,
in which a liquid emulsion is formed based on blood, water
and protein and a pressure drop is caused by passage
through narrow slits. This process does not allow chunks to
be manufactured.
The aim of the present invention is thus on the one hand to
manufacture thermo-irreversible chunks having a more
attractive appearance from a blood-lipid mlxture and on the
other hand to be able -to dice these pieces perfectly or
convey them in order to use them subsequently in a canned
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food or a terrine or a sauce dish for example for domestlc
animals. This method is employed ln a totally contlnuous
manner.
The invention concerns a method according to the preamble
to Claim 1, in which a source of proteins and/or
hydrocolloids is added to a blood-lipld-water mixture
before or after homogenization.
Blood acts as an emulsifier and gelling agent and is used
at a rate of 30 to 60~, preferably at a rate of 45 to 55%.
Blood is taken as meaning any blood product or blood
derivative such as pig blood, ox blood, veal hlood, plasma,
haemoglobin and red blood cell concentrate. All percentages
in the present description are given by weight. The lipid
content lies between 20 and 50%, preferably between 25 and
35%. Lipid is understood as meaning both animal or
vegetable fats, which are either liquid or solid at room
temperature, for example pork fat or soya oil.
?0
Masking the colour of the blood and other elements in the
matrix contributes to its improved appearance. The colour
is masked by means of a homogenization of the lipid and the
blood containing aqueous phase. Due to the contribution of
the blood to the stabilisation of the resulting lipid
micelles, their size is sufficiently small to reflect a
high proportion of incident light. This results in a
whitening effect, attenuating the impact of the colours in
the matrix.
Heat treatment of the emulsion enables the proteins in the
mixture to be coagulated and hence solidified, but in order
to obtain a very firm gel which can be diced cleanly
according to the invention, a source of protein and/or
hydrocolloids is added.
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~3~2
The term "whlch can be diced cleanly" is taken to indicate
that a solid matrix is obtained which can be cut up hot or
conveyed without forming more than 5% of particles having a
size less than 5 mm.
~his protein source is added at a rate of 0.1 to 20~o and
the hydrocolloids at a rate of 0.1 to 2-~.
Protein source, in the present description, is taken to
mean meats or meat by-products, vegetable proteins,
proteins having a microbial origin, fish or offals. Meat is
taken to mean chicken, rabbit, bovine or ovine meat or
dried meals, obtained from the carcasses of the
aforementioned animals. Offals are taken to mean lights as
well as livers and kidneys. Fish is taken to mean any type
of fish or fish meal. The function of this supplementary
protein addition is to enable a gel to be obtained which is
firmer and can be more easily diced in the form of cubes
with minimum losses of fines. Blood plasma if preferably
used as -the source of protein. This plasma is the liquid
fraction of blood after separation of the red blood cells
from the whole blood preferably aFter addition of
anticoagulants. The plasma may also be used in the form of
a powder.
Hydrocolloids are taken to mean any type of gelling agent
or thickener, preferably konjac, guar~ kappa-carrageenan,
xanthan, or mixtures thereof. Homogenization is carried out
in a known manner, either with high pressure systems, or
with a hydrocolloid disperser, so as to obtain an emulsion
with a milky appearance.
Heat treatment is carried out in a tunnel oven at a
temperature of the order of 100C for 30 sec to 5 minutes.
Heat treatment may also be considered in a refiner-
texturizer at a temperature of between 70 and 110C for
about 30 sec to 5 min, preferably for about 2 min. A
refiner-texturizer, for example a trigonal made by the
SIEFER company, is taken to mean an apparatus comprising a
stator and a rotor. The function of this apparatus is to
disperse a liquid in a solld between the rotor and the
stator by reducing the particle size between the rotor and
the stator. In the present invention, the refiner-
texturizer raises the temperature of the emulsion andbrings about gelling of the hot mixture. The gelled mixture
is removed from the outlet of the refiner-texturizer by
means of a tube having a definite length, and is cut up
into pieces with a chosen regular shape by means of a
suitable system. In order to facilitate extrusion, steam is
injected at the outlet of the refiner-texturizer.
The product obtained according to the method of the
invention is diced into the deslred shape and added,
without the need for further treatment, to terrine, micro-
ground meats, sauce dishes or sausages for food products,
at a rate or 5 to 80%. The final product is then stabilized
before consumption, either by heat treatment, for example
sterilization, or by refrigeration or freezing. The dicing
Z5 occurs preferably with the hot exiting product.
It should be noted that the solid food matrix obtained i9
thermo-irreversible, that is to say it withstands heat
treatment at least at 70C without liquefying.
In order to show the masking of colour it is important on
the one hand to quantify the red colour of the blood itself
and of the emulsion prepared according to the invention and
on the other hand to measure the hardness of the gel
obtained. These data will be referred to in the
continuation of the description with reference to examples.
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213~ ~2
Example 1
43 kg of pork fat, melted by means of microwaves, and
containing 20 g of antioxidant (BHT), is added slowly to a
mixture of 27 kg of fresh blood to which 5 kg of powdered
ox blood plasma has been added together with 26 kg of water
containing 0.5 kg of sodium nitrlte and 5 kg of NaCl.
Mixing is carried out under conditions of high shear for 2
min. Homogenization is then carried out at a pressure of
340 bar at a flow rate of 30 litre/hour at 45C. After this
treatment, the intensity of the red colour is measured with
an Agtron M63 reflectometer using a red filter on the 0-33
scale.
The result is expressed in % of reflected light passiny
through the filter. The higher the value, the lower the red
intensity. A value of 83~ was found in the present case,
whilst for blood it is close to 0.
Ohe mixture is then introduced into the refiner-texturizer
where it undergoes heat treatment for 2 min at a
temperature of 80C. The hardness of the gel obtained is
then measured at this time using a Stephens LFRA 100
penetromer with a TR5 probe. A pressure of 620 g/cm2 is
necessary to penetrate 11 mm into the mass. It is
considered that a good strength gel is obtained within the
range 400 to 1200 g/cm2. The pieces obtained are then diced
into the form of 5 mm cubes and 30~ of these cubes are put
into a terrine base which has been sterilized at about
130C
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6 --
2133i~2
E~ample 2
Operations are carried out under the same conditions as in
Example 1 with 50 kg of fresh ox blood, 30 kg of soya oil,
0.5 kg of K-carrageenan, 0.5 kg of KCl, 0.5 kg of guar gum
and 18.5 kg of water. A final product is obtained giving a
value of 75~i reflected light through the red filter and a
gel strength of 560 g/cm2.
Example 3
Operations are carried out under the same conditions as in
Example 1 with 50 kg of frozen ox blood, 30 kg of soya oil,
5 kg of frozen blood plasma, 0.5 kg of K-carrageenan, 0.5
kg of KCl, 0.5 kg of guar gum and 13.5 kg of water.
A final product is obtained giving a value of 89~ reflected
light through the red filter.
Example 4
Operations are carried out under the same conditions as in
Example 1 with 40 kg of frozen ox blood, 20 kg of tallowl
kg of whole micro-ground lean fish, 0.5 kg of K-
carrageenan, 0.5 kg of KCl, 0.5 kg of guar gum and 1808 kgof water, the difference being that homogenization is
carried out in a single step at atmospheric pressure in a
hydrocolloid disperser for 20 minutes.
A final product is obtained having the same properties as
those of Example 1.
Example 5
Operations are carried out under the same conditions as in
Example 1 with 50 kg of frozen ox blood, 30 kg of lard, 1
7~ ~3~2
kg of powdered plasma, 0.3 kg of konjac and 18.7 kg of
water. A final product is obtained giving a value of 79~ of
light reflected through the red filter.
