Note: Descriptions are shown in the official language in which they were submitted.
METHnD OF AGGLOMER~TING A~ ~EFLAVORI~G PE~ FLOURS
PF~ PROTFIN CO~'CE~TRATES A~D PRODUCTS THE~OF
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The in~T~ntion herein described relates to a method of Proce~sin~
flours or prot~in concentrates obtained from legumes such as peas, for
example fielcl peas (Pisu~ Sativum)l agglomerates of a beadlike nature which
are essentially bland in flavour, and to the incorporation o~ these agglo-
merated su~stances or ~ixtures into foods.
By pea flour is meant the product of dry mi~ling of dehydrated
whole or dehulled peas, and bv pea protein concentrate is meant the
product of an air classification process b~ means of which pea flour is
separated into a starch rich fraction and a protein rich fraction which
protein fraction constitutes a pea protein concentrate. Other foodstuffs
can be soya flour or soya protein concentrate, proteinaceous materials
such as casein,gluten, fish protein concentrate, nutmeats, etc., cereal
flours, sugars and vitamins and minerals, for example.
A common method of preparing protein rich concentrates from
peas consists of dehydrating the peas, milling the dried peas into a
flour, and fractioning the flour into protein and starch rich fractions by
means of separation with air. The dried peas are first cleaned, possibly
dehulled, and ground to a fine flour which is 90% less than 325 mesh in
particle size (90% less than 0.0017 inches in diameter), where mesh refers
to the number of screen openings per lineal inch of screen. ~ typical
composition of pea flour obtained from whole ground peas might be as
follows: protein - 26%, starch - 44%, fibre - 7%, lipids - 2.5%, ash - 3%,
non-fat extract - 17.5%. If the peas are first dehulled, much of the fibre
is removed as the hulls consist of approximately 80% cellulose and represent
about 8% by weight of the peas.
hn~en dried peas are ground to a flour the fragile protein rich matrix
of endosperm which encapsulates the starch granules is fragmented into very
fine particles while the starch granules remain basically intact due to their
resistance to grinding. Conse~lently, it is possible to separate the lighter
protein rich fines from the heavier starch granules simply by air classificationof the flour. The separation is not complete, as some bro~en starch granules
are carried over with the protein rich fines, and some large unbroken
agglomerates of endosperm (containing protein) remain in -the coarse starch
fraction.
In a typical separation process, for example, in which 100 lbs of
pea flour from dehulled peas consistins of approximately 29% protein, 47%
starch, and 17% non-fat extract which consists of oligosaccharides (sugars),
the balance being ash, fibre and lipids, is classified with air, 31 lbs.
of a protein rich fraction consisting of 60% protein, 11% sugars, 8% starch
and 4~ lipids, and 6g lbs. of a starch rich fraction consisting of 14-15%
protein, 53% starch, 5% sugars and 1.5% lipids are obtained.
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In order to further separate the remaining protein from the starch
fraction, it is necessary to re-grind this fraction to break down the
remaining agglomerates of endosperm and to re-classify with air. Consequently,
17 lbs. of a second protein rich fraction consisting of 40% protein, 28~ starch,10% sugars, and 4% lipids, and 52 lbs. of a final starch fraction consisting
of 5~ protein, 78% starch and 4% sugars is obtained.
The protein rich fractions or mixtures of such fractions, generally
known as pea protein concentrates, obtained by these prior art methods,
generally contain 40 - 6% protein and are 9o% less than 800 mesh in
particle size, ( 90% less than 0.00106 inches in diameter). These materials
also possess a characteristic pea-like flavour and a bitter taste which in all
likelihood is due to the presence of lipids, phytic acid and volatile compounds
in these materials. The pea flours generally contain 2.5% lipids and 1.5% - 2%
phytic acid and when these flours are air classified to produce the concentrates,
the lipids and phytic acid are carried over into the concentrates, resulting in
typical concentrations of 4.0-5.0% lipids and 1.5-2.0% phytic acid in the
concentrates.
According to prior art, the pea flours or pea protein concentrates
produced by dry milling or air classification methods can be used to prepare
protein enriched foods, such as bread or cookies, for example, by straightforward
addition and/or blending without subsequent treatment prior to incorporation.
However, the food products obtained are generally unsatisfactory in that they
have unacceptable flavour and texture characteristics, and in most cases are
unpalatable.
Firstly, the flours, or concentrates, are very fine in particle size;
they possess high water absorption characteristics; and the proteins in the
flours or concentrates, do not have desirable water binding properties.
Consequently, when these materials are incorporated into bread or cookie doughs,for example, in order to obtain sufficiently high protein levels in the final
products, an amount of flour or concentrate, which represents 5-10% of the
formula weight, produces doughs which are dry and crumbly or tough, and are
difficult to form or mold, which characteristics necessitate either the additionof excess water to the doughs or a reduction in the amount of flour or concer.trate
used. Furthermore, after baking, these products are moist, dense or hard and donot have an open texture in the case of a bread product or a crisp and crumbly
texture in the case of a cookie product, such texture characteristics being
most desirable.
Particularly in the case of pea proteinconcentrates,for example, ~ins
to the high protein and relatively high sugar content of these materials, it
is extremely difficult to disperse or dissolve these materials in water, and theresulting mixtures can be excessively sticky or pasty in character. When the
concentrates are used to prepare bread or cookie doughs, owing to the high moistur~
absorption characteristics and the poor water binding properties of the
concentrates, excess water must be added in order to obtain doughs of workable
characteristics. Consequently, after these products are baked, further dryi~g
is required to reduce the moisture levels in order to improve shelf life or
keeping qualities of the product. In the case of cookies or biscuits, a hard
or dense and moist product results so that it is sometimes necessary to use
an excess of leavening agents or of eggs in order to provide good biscuit
texture and to aid drying without case hardening, or to perforate the biscui,s,
or to dry th~m for several hours after bakiny, at reduced temperatures, to obtain
acceptable finai moisture levels.
When the flours or concentrates are used to prepare pasta doughs, snack chip
doughs, beverage drinks, or are added to ground meats as an extender, similar texture
problems occur, due to the sticky, pasty nature of these materials and due to their
relatively poor water binding characteristics~
Secondly, in these raw flours and concentrates are present trypsin inhibitors,
enzymes responsible for oxidation and rancidity in these materials, and toxic
substances, all of which cause the flours and concentrates to be indigestible or unfit
for human consumption without further heat processing prior to consumption. Such hea-
treatment is usually achieved by heating or cooking the foods to which the concentrat
or flours have been added; however, such practice does not necessarily ensure that
harmful factors have been destroyed, depending on the cooking method used, or the nat;
of the product being heated or cooked. Consequently, the raw flours or concentra_es,
may not be used in foods which do not involve a cooking step in their preparation.
Thirdly, the flours and concentrates obtained from peas by dry milling znd
air classification methods, contain pea flavours and a bitter taste characteristic
of the raw seed. The bitter taste of pea flours and concentrates is thought to be
due to the presence of oxidized phospholipids, such oxidation being promoted by a
lipase enzyme present in the flours and concentrates. These flavours and bitter tast~
are especially concentrated in the protein fractions, but are also present to a more
limited extent in the original pea flours. Consequently, when these materia~s are
used in food products, the flavour and bitter taste of raw peas is transferred to
these products and is only partially removed by cooking or baking.
Finally, the flours and concentrates produced from peas, by air classificatio
techniques, are not free f:Lowing and are extremely difficult to transport, or to
store owing to their fineness of grind. Vse of the flours and concentrates in rixing,
bagging or transferring operations results in the production of a fine dust which
coats equipment and processing areas and is difficult to remove by washing with water
due to the sticky nature of these materials. In addition, the flours and conce~trate~
have relatively low bulk densities which necessitate the use of high volume storage
systems and result in relatively high costs of shipping or transporting the flour
and concentrates.
In practice, it is found that a moist-heat treatment method may be used to
reduce or eliminate pea-like flavour and bitterness of pea flours and concentrates
obtained by milling and air classification. In one such example of a prior art
treatment method, the flours or concentrates are slurried in water, the slurries are
heated to sufficient temperature in order to reduce or remove the raw pea-like
flavour and bitterness, and the slurries are drum-dried or spray-dried, to obtain a
bland flour or concentrate, which may then be added to foods. In a second such exæm~~
of a prior art treatment method, the flours or concentrates are exposed to mois, steæ-
at a temperature of 212F ~100C) or greater, for extended periods of time.
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In all of the above described prior art treatment methods, the removal
of pea flavours is thought to be due to ~he removal of volatiles, which are
present in these flours and concentrates, by a common physical chemical
technique, kno~ as steam distillation, and the removal of bitterness is
thought to be due to the destruction of enzymes which promote oxidation
of phospholipids, through the use of heat. The principle of this steam
distillation technique, is that when steam is blown through a liquid which
is immiscible with water (that is to say, insoluble in water), the resulting
vapour contains both steam and a vapour of the immiscible liquid so that
the immiscible liquid itself is distilled and may be condensed overhead,
together with the steam. In this way, vapours of flavour compoments of the
pea flours and concentrates, which are immiscible with water, are distilled
when these materials are subjected to steaming treatments, or to moist-heat
treatments. (The lipids and flavour components are insoluble in water, and are,
therefore, removed by steaming or by moist-heat treatment.)
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The disadvantages of such prior art treatment methods are that,
firstly, owing to the high temperatures employed~ to the extended processing
times employed~ to the degree of moisture used, or to the presence of oxygen
during processing, essential amino acids or vitamins may be destroyed, so
that the nutritional value of the products is decreased; secondly the
products which result, do not necessarily have such desirable characteristics
as reduced stickiness or pastiness, or flowability etc. which deficiencies
cause these products to be unsuitable in the preparation
of certain foods; and lastly, the energy costs to remove added moisture from theproducts by drying, tespecially in the case where a slurry method is used),
are excessive and prohibitive to the practical use of these methods. Conseq~ently,
when these prior art processes are used to treat pea flours and protein
concentrates, the treated materials are not entirely suitable for the preparation
of food products, apart from the fact that they may have reduced pea-like flavour.
To conclude, raw pea floux and pea protein concentrates obtained by
dry milling and air classification of peas are not suitable for use in foods
without treatment to remove raw pea flavour and bitterness, and to make the
pxoducts easier to handle and to incorporate into various foods. Such methods as
are presently used to treat raw flours and concentrates, result in products
which are not entirely suitable to be used in foods, due to their low nutritional
value and to other undesirable characteristics, and such treatment methods are
expensive to employ.
It is, therefore, an object of this invention to prepare pea flours
or pea protein concentrates in forms which are essentially bland in flavour,
which do not have a bitter taste. Such forms are free-flowing, have relatively
high bulk densities, and are generally superior to flours and concentrates
prepared according to prior art methods.
It ~s another object of this invention to prepare pea flour and pe2
protein concentrates in forms which may be readily utilized in various foods
without causing excessive stickiness or pastiness, or mechanical forming pro~lems,
thereby resulting in food products superior in flavour and texture characteristics
to similar products produced by prior art methods, and also to prepare admix~lres
of pea flours and pea protein concentrates with other foodstuffs, which admixtures
can readily be processed into secondary food products by means of a secondary
processing step, said admixtures themselves being new food products, which were
hitherto unknown to the prior art.
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It is a further object of this invention, to moist-heat treat
pea flours an~ pea protein concentrates and to produce forms thereof
which ha~e superior nutrltional value to ~hose products pro~uced by
prlor art moist heat-treatment methods, which fo~ns are readil~ digestib'e
and may be added to or used in foods whose preparation utilizes a
minimum of cooking or heatlng prlor to cons~ption.
Still another object of this invention to prepare such forms
of pea flour and pea protein concentrates as above described, by use of a
moist, heat-treatment and drying method, which is less cos~ly than prior
art moist heat-treatment and drying methods, by virtue of low energy
requirements to dry the moist heat-treate~ fo.rms, increased ease of
tran~porting or storing t~le resulting products, reduced volumes required
to store or to transport the pro~ucts, ~Id ease of incorporating or
forming the products into various foods by means of commonly known
food processing equipment.
The present invention, in one embodiment, resides in a process for
agglc~nerating and deodorizing pea flours, pea protein concentrates, or
admixtures of pea flours or pea protein concentrates with other foodstuffs,
said admixtures containing at least 25~ by weight of said pea flours or pea
protein concentrates, which process comprises: ta) charging said pea flours,
pea protein concentrates, or said admixtures to a treatment chamberJ (b)
agitating said charge while spraying same with water or suitable aqueous
solutions or emulsions in the amount of about 5% to about 30% by weight of the
dry charge, thereby to form bead-like agglomerates having between about 12
and about 30% by weight of moistureJ (c) heating the agglomerated flours,
concentrates or admixtures to a temperature in the range of 185 -200 F, thereby
to remove pea-like flavour and bitterness from the material; and (d) drying
said agglomerated flours, concentrates or admixtures at a temperature in the
range of lO0 -130 F.
In its broadest process embodiment, the present invention resides in a
process as defined in the immediately preceding paragranh, hut in which the
flours or protein cnncentrates are not limited to those derived from peas,
but may be derived from any edible legume.
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In another embodiment, this invention resides ln a bland flavored,light-
colored, free-flowing, bead-li~e agglomerate having a relatively high bulk
density, said agglomera-te belng either of (1) pea flour, or pea
protein concentrates or (2) of mlxtures of pea flour or pea protein
concentrates wi.th other foodstuffs such as cereal flours , starches,
dehydrated vegeta~le flours, soya flour, soya protein concentrates,
casein, gluten, whole egg powders, eag albumen, milk powders and
fish protein concentrates an~ o?tionally, one or more other ad~itives such
as sugars, salt, malt, cocoa po~der, citric acid, phosphates,
sodium bicarbonate, vitamins, minerals, essential oils, vegetable
oils, lecithin, butter and other fatty or waxy materials, emulsifiers~
flavourings ar,d cclors. Sald mixtures contain at l~ast 25~ b~
weight of said pea flours or pea protein concentrates. The afore-
said agglomerates are made by the process recited above.
According to the process aspect of this invention, pea flours or pea protein
concentrates, obtained by grinding ancl air classification of peas, or
admixtures of these flours and concentrates with other foodstuffs, with or
without additives, are first sprayed with water or with an a~ueous solution or
emulsion in the amount of 5% to 30% of the dry material by weight while being
agitated, in order to form bead-like agglomerates.
These agglomerates are then subjected to a heat treatment method
while still in their essentially moist state, by heating the agglomerates
to temperatures of 185-200F, in order to remove pea-like flavour and
'bitterness, and to inactivate enzymes present in the original flours
and concentrates.
Finally, the agglomerates are dried to a moisture content of 12go or
less, or to a moisture content suitable to prevent spoilage on extended periods
of storage, and are then ground and/or sized to obtain products with a
uniform particle size distribution.
Agai.n, as wi.th the process aspect, the present inventi.on in its
broadest product aspect, resides in a bland flavored, light colored,
free-Elowing, bead-like agglomerate as described in the first paragraph
on this page, but wherein the flour or protein concentrates are not limited
to those derived from peas, but may he derived from any edible legume.
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I.~.ere admixtures of the pea flours ~r pea protein concentrate5 with
other foodstuffs or additives are contemplated, the other foodstuffs
m~y consist o~ such materials as
cereal flours, dehydrated vegetable flours, or proteinaceous materials such
as nut meats, soya flour, soya protein concentrates, casein, gluten, dried egg
albumin, or whole egg powder, fish protein concentrate, or yeasts, etc.
The additives may be sugars, salt,cocoa powders, citric acid, phosphates,
sodium bicarbonate, vitamins, minerals, flavourings or colours, etc. The
aqueous solutions may consist of sugars, salt, colours and flavours,
emulsifiers and wetting agents, etc., dissolved in water and the emulsions
may consist of essential oils or flavours, vegetable oils, lecithin, and
other fatty or waxy substances dispersed in water with the aid of suitable
emulsifiers.
The pea flours or concentrates or admixtures are agitated while being
s~-ayed in order to effect z uniform dispersion of the aqueous solution or
emulsion and to form agglomerates of a bead-like nature and uniform particle
size. The agitation can be suitably carried out using types of mixers such as
ribbon blenders, V-cone blenders~ double cone blenders, vacuum mixers, or in a
fluidized bed chamber. In these types of mixers, agitation of the flour
or concentrate is achieved either by means of blades or paddles such as in a
ribbon blender or in a vacuum mixer, or by rotation of the mixer itself to
produce a tumbling mixing action as in the case of a V-cone or double cone blender,
or by means of blowing air or gas directly through the flours or concentrates
as in the case of a fluidized bed chamber.
The spraying action can conveniently be carried out by means of nozzles,
spray bars or special dispersion bars common to these types of mixers. The
liquid to be sprayed is pumped or is introduced by gravity flow and is unifor21ydispersed into the flours or concentrates. In addition, the V-cone, double coneor vacuum type mixers can also be equipped with chopper blades which rotate at
relatively high speeds of 1750 - 3500 r.p.m.* and create a uniform dispersion ofliquid throughout the solid mixture and also control the final particle size of
the mixture by brea~ing up larger sized agglomerates.
* (revolutions per minute)
In examples characteristic of the process of the invention, it
is four.d that when water is added to the pea flour or concentrates by means
of a uniform spray, or by other liquid disperson techniques, owing to the
stickiness or pastiness of these materials, the particles are wetted and
are immediately coated with adjacent fine particles of unwetted material
to form bead-like agglomerates. The siæe of these agglcmerates may be
controlled by the rate of addition of water, by the size of water droplets
sprayed into the mixture or by the degree of agitation, or by the degree of
chopping or cutting action wherein a chopper blade is used.
It is found for example, that effective agglomeration and
deflavouring of pea flours and concentrates is achieved through the use of
lQ-25% of the dry material weight as water, and most effectively through the
use of 15-20% by weight of the material as water. As the moisture content
of the original flours and concentrates is generally about 10~, the addition
of 15-20% water by weight, causes the wetted materials to have an overall
moisture content of from 20 to 25~ by weight. When the amount Or water added
is less than 10% of the material by weight,
not all of the material is agqlomerated, and the
material may have residual pea flavour and bitterness after drying. When the
amount of water added is greater than 25%, the material is practically totally
agglomerated, and has no residual pea flavour and bitterness, but is dark in
colour, and possesses a higher degree of denatured or insoluble protein than
when processed at lower moisture levels. In the case of flour or concentrate
admixtures and other foodstuffs the amount of water to be added varies between
5 and 30% by weight, but is generally 15-20% of the pea flour or pea concentratepresent in such admixtures.
It is found that when the moist agglomerates are heated to temperatures
of 185-200F or (85-95C) pea flavour and bitterness are effectively removed.
When the maximum temperature during heating exceeds 200F (95C~, a dark
coloured product is obtained which has a high degree of insoluble protein. hnenthe maximum temperature during heating is below 185F (85C) it is found that
pea-like flavour and bitterness are not completely removed. Therefore the
optimum, maximum temperature range is found to be between 185-200F. In adciticn,
it is also found that it is not necessary to hold the temperature within this
maximum range for any period of time. Effective removal of pea flavour and
bitterness is obtained simply by allowing the agglomerates to reach the maxi~lm
temperature, and then to immediately dry the agglomerates at lower temperatures,for example, by inducing a vacuum on the mixing cham~er or by introducing dr~
air through the agglomerates. The resulting agglomerates are bland, and have
acceptable colour and soluble protein characteristics.
Additionally, it is found that when an inert gas bleed is passed through
the moist agglomerates during the heating step, oxidative changes are minimized
and the product generally has a more acceptable colour after heating and drying.The inert gas bleed also helps to remove vapours which are evolved during the
heating step, and to prevent condensation of these vapours on the product.
A similar reduction in colour is noticed if an acid such as citric or phosphoricacid is added in the amount of up to 0.5~ by weight to the pea flour or
concentrate before heating. The resulting products generally have a light
golden-brown colour, but a slightly lower soluble protein content due
to denaturation of the protein by the acids.
After heat treatment the agglomerates are dried at product
~emperatures of 100-130F(or 40-55C)using conventional drying techniques.
When product temperatures lower than 100F are used, drying rates are slow.
If product temperatures exceed 130F excessive denaturation of proteins
present in the pea flour and concentrates may occur, and the materials
may develop a dar~ colour.
The conventional techniques used can be hot air drying, or
vacuum-heat drying. Such heat treatment can conveniently be carried out
in the mixing chamber which is used for the agglomeration process. For
example, heat may be applied to a jacket on the mixer by means of steam,
hot oil or hot water, or the p}oduct dried by circulating hot air through
the mixer or by pulling a vacu~m on the mixing chamber. In the case of a
fluidized bed chamber, for example, product may be dried simply by circulating
the hot air throu~h the bed. ~he materials may also be heated through
the use of dlelectric or microwave methods.
After the beaded agglomerates have been dried, they may be screened
to separate ooarse particles and fine particles from the product. For
example, two screens with different hole sizes, might be used such
that an over sized fraction is retained on the upper screen (large hole
size), a product fraction passes through the upper screen and is retained
on the lower screen ~small hole size) and an under-sized fraction consisting
of fines passes through the lower screen.
It is found that when the heat treated agglomerates are dried and
sized in this fashion, hard, dense, bead-like particles are obtained. These
particles exhibit reduced pastiness and stickiness when dispersed in water,
and have little or no residual raw pea flavour or bitter taste.
Such difference in properties can be immediately distinguished simply
by tasiing the flours and concentrates and the products of the process of
this invention.
To illustrate the above described method of agglomerating pea flours
and pea protein concentrates, a flowsheet for the process is shown in Pigure 1.
The extent of processing variables such as time and temperature employed for
each step of the process, is illustrated by means of a typical processing curve,as ~3yen in Fiqure 2.
~ l~ith reference to the processing curve of Figure 2, and
only by way of example, the time x
for the agglomeration of a pea flour, pea protein concentrate, or admlxture,
during which aqueous solution or emulsion is added to the dry material, may varybetween 1 and 10 min.; the time y, during which the wetted material
is heated to the maximum temperature a, ~nd is subsequently deflavoured and
debittered, may vary from 20 to 40 min; and the time z, during which the
heat-treated deflavoured agqlomerate is dried to a final moisture content of
12% or less, may vary from 20 to 40 min. In addition, the maximum temperature
a, reached at the end of the heating period y, may vary from 185F to 200F;
and the temperature b at which the agglomerate is dried, may vary from 100F
to 130F, for example. Preparing pea flours, concentrates or admixtures
using the processing parameters as described above~ will generally result
in acceptable products.
lllBZ7~
According to the process of this invention, various time values for
the parameters x, y and z, other than those values described above, would
produce comparable results. For example, a shorter heating time (i.e. a
faster heating rate, for y less than 20 min), would result in less destruction
of nutritive value in moist pea flours and concentrates, but provided that a
final temperature between 185 F and 200 F is reached, pea flavour and bitterness
would still be removed. Such heating might be carried out in continuous fashion,
by using a fluidized bed for example, or by rapidly and continuously feeding themoist agglomerates into one end of a heated zone, and continuously removing
the heated agglomerates from the opposite end of this zone.
Contrarily, a longer heating time (i.e. slow heating rate; y greater
than 40 min.), would result in greater destruction of nutritive value, by
virtue of the fact that the material is subjected to high temperatures for
relatively long time periods. With regard to the maximum temperature range
employed, if the agglomerate were processed at a maximum temperature a of 210F,for example, the resulting product might still be acceptable for use in certain
foods as relates to its physical properties such as flowability, and ease of
incorporation etc, but would generally have an inferior nutritional value and aninferior colour, etc. when compared with products made at temperatures of
185 - 200 F. Similarly, an agglomerate processed at temperatures below 185 F,
would have unacceptable pea-like flavour and bitterness etc, when compared to
a product made at a temperature of 185-200 F.
lhe temperature at which the product is dried, would have similar
effects on the properties of the product, but, generally, it is found that
acceptable products are produced when the materials are dried at a temperature
of 100 - 130 F.
When the products of this process, are compared to raw pea
flours and concentrates with regar~ to their physical characteristics, it
is found that the products are free-flo~ing and have lower a~gles of repose
than the original materials. Moreover, it is found that especially in the
case of pea protein concentrate, the hulk density of the agglomerated
concentrate is as much as 3 times greater than that of the raw concentrate -
for example, the bulk density of agglomerated pea protein concentrate is 50
and 60 lb./ft.3 as compared to 20 lb/ft.~ for raw pea protein concentrate.
The products of this process can be added to various food products.
It is found, for example, that in the case of a cookie product, where
agglomerated heat-treated pea protein concentrate is used, the doughs are soft,
moist and workable. These doughs are easily handled using conventional wire-cutcookie machines, and the ba~ed products possess e~cellent flavour cand texture
characteristics. It is also found that 10% or more of the agglomerated
heat-treated pea protein concentrate can be used to prepare these doughs,
based on total formula weight. Consequently, it is possible to achieve
relatively high protein levels in these products, through the use of
agglomerated pea protein concentrate. When similar doughs are prepared using
unprocessed pea protein concentrate, the doughs become dry and cxumbly and it
is necessary to add excess moisture to the doughs. In addition, the products
obtained after baking are moist, dense and hard, and have an objectionable
pea-like flavour.
In general, the products of this invention are easy to incorporate
into food mixtures, such as bread, cookie or pasta doughs, or can be used
as meat extenders. They do not cause excessive stickiness or pastiness,
nor do they require the addition of excessive quantities of water in order
to obtain workable mixtures. Consequently, these food mixt~Lres or doughs
c~n be readily handled in conventional equipment and do not require extensive
handling or processing techniques.
Finally, it is found tilat various food admixtures can be produced by
the method of this invent:ion. For example, a mixture of ~ea flour and pea
protein concentrate, or a mixture of pea flour or pea protein concentrate with
either corn starch, pea starch or other starch such as wheat starch, ta~ioca
starch and/or rice starch can be agglomerated by the
process of this invention. When such admixtures contain pea flours or pea
protein concentrates in amounts greater than 25% by weight of the admixture,
it is noticed that the admixtures have a characteristic pea-like flavour,
and a bitter taste. Furthennore, it is found that the pea-like flavour and
bitterness can be removed from such admixtures by the process of this invention,and that the resulting agglomerated admixtures can be used to prepare various
secondary food products. For example, a snack food product can be prepared
by a secondary processing method, whereby the heat-treated agglomerated
admixture is formed into a dough by the addition of water, and is sheeted
or extruded to produce a flaked product which may then be deep-fat fried, or
a pu~fed-expanded product which is made ready t~ eat by the addition of
suitable fats and seasonings.
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Similarly, a breakfast cereal admixture consisting of pea protein
concentrate and an added starch, toyether ~ith various flavourings and
additives, can be agglomerated by the method of this invention. Such
agglomerated admixture may then be formed into a flaked cereal product or a
puffed-expanded product according to the above described methods.
Such heat treated agglomerated admixtures exhibit reduced stickiness
and pastiness, are bland in flavour, have higher bulk densities than the
original untreated admixtures, are free-flowing, and can readily be formed
into acceptable products using conventional snack and cereal processing
equipment.
Such admixtures based on pea flours and pea protein concentrates,
and produced by a heat treatment agglomeration method, are unknown to the
prior art, and result in secondary snack and cereal products with higher
protein contents and higher nutritional value than hitherto obtained by
processing pea flours or pea protein concentrates by prior art methods.
Although this invention employs a moist heat-txeatment method,
as do other prior art processes, the differences between the method
of this invention and prior art methods are that:
The amount of water used in agglomeration is substantially less
than the amounts used in a slurry process for example, so that
energy costs of drying the agglomerate are considerably reduced
over drying costs for these other processes. The maximum temperature
employed during heat-treatment, is lower than the temperatures
used in other prior art heat treatment processes; consequently, the
products of the process of this invention have higher nutritional
values than those products made by prior art methods. Finally,
the process of this invention results in products and in secondary
food products which were hitherto unknown to the prior art, and
although pea flours, pea concentrates and various admixtures
containing these materials and other food stuffs can be prepared
by prior art methods, such products are inferior to the products
of the process of this invention.
The description herein is given with particu]ar reference to the
processin~ of ~ flours or pea protein concentrates; however, this invention
is applicable to the process of flours and protein concentrates obtainable
from other edible legumes as well, as for instance, from the various types
of beans, and from lentils and peanuts.
The present in~ention is further illustrated bv the follol~lng examples;
however, it is to be understood that it is not applicant's intention that the
invention be in any sense limited thereby:
~LE 1
An agglomerated 2ea ~rotein concentrate.
70 lb. of a pea protein concentrate containing 50~ protein by wgt. 3
derived from pea flour by an air classification process, was charged to a
treatment chamber equipped with mixing blades and a chopper blade.
12 lb. of water was sprayed into the concentrate, with suitable agitation
of the material provided. The water added represented 17% of the concentrate
by weight.
The mixture was then heated to a temperature of 185 F, which heatin~
action required 30 minutes, and the heat treated agglomerate was then dried
in 30 minutes using a vacuum pressure of 28-29 inches of mercury to a final
temperature of 120F, and a moisture content of 9.5%, according to the typical
processing curve of Figure 2.
The resulting product was a free-flowing, dust free, bead-like
agglomerate, which had virtually no pea-like flavour and no bitter taste. Its
properties are shown in Table 1. This product ~as then ground to a uniform
particle size and used to prepare various food products, as in Examples 9 and 10hereinafter.
TABLE 1
.._ - .~ _ _ _
Moisture Protein % Nitrogen Bulk Plate Moisture
Solubility ~ensi3tY Count absorption
index lb/ftcapacity
50~ ~ _ _ 5/100 5.
Raw Concentrate 10.13% 47.48% ¦ 60% 23 18,200 452
. ._ _ _
Agglomerated 50%
concentrate8.24 50.13 55.3~ 56.65 4,300 481
.. __ _ _ .
Particle Pea Bitterness Colour
Size Flavour
. _ .
90% thru. Strong Strong Light
800 mesh__ yellow
90% above Slisht No Golden
100 mes~ ~ea bitterness yellow
- 12 -
EX~PLE 2
Agglomerated pea protein concentrate - inert gas bleed used.
70 lb of a protein concentrate containina 60% protein by wgt.,
derived from pea flour by an air classification process, was
charged to a treatment chambe~ and water added as in Example 1.
The mixture was then heated to a temperature of 185F in 30 mins.,
and nitrogen gas was passed through the mixture at a rate of 15
cubic feet p~r hour, during the heating period.
At the end of this period, the nitrogen gas bleed was stopped,
and the mixture dried as in Example 1.
The product obtained was similar in physical characteristics to that
of Example 1, except that a lighter colour was evident. (See Table 2).
TABLE 2
=_ _ __ Moisture % Protein Nitrogen ~ Bulk Molsture
Solubility ¦ Density Absorption
Index I lb/ft3 a~100 a
__ _ _ . _ , .,
Raw 60% 8.81 62.2 84.4 20.0 547
~oncentrate
_ .. . _
hgglomerated 8.77 63.0 68.4 58.5 560
60% Concentrate
.. _ _ ... .. _ .. ... ~
Particle Pea Bitterness I Colour
Size Flavour
. .. _ ._ _ _
90% thru. Very Very Light
800 mesh strong strong yellow
_ .~ _ __ _ ._
90% above Slight No Light
100 mesh cooked bitterness golden
_ _ pe~ _ yellow
The product was used to ma~e a pasta product as in Example 14.
~L18;;~7~
- 13 -
EX~LE 3
Agglomerated pea concentrate with acid added.
As in Example l, only 2 114 oz. of citric acid was dissolved in the
agglomeration water. The amount of acid used, represents approximately 0.2%
of the weight of the concentrate.
The results (see Table 3) were similar to those obtained in Examples l
and 2, only the material was very light in colour, and the colour ~as similar
to that of the raw concentrate.
TA~LE 3
.. _ . _ __ _ ~ _ _ - _ I - l
Moisture Protein Nitrogen Bulk Particle Pea Bitterness Colou
% % Solubility Densit~ Size Flavour
Index _ lb/ft. _ - ~-~ -1- -
Raw 50~ 90% thru Strong Strong Light
~oncentrate 10 13 47.48 60% 1 23 800 mesh -- I yel
~gglomerated 9.02 48.36 ~6% 56 9o% None None Very
50% above slight light
~oncentrate _ _ ~ 100 mesh ~ ¦ yelldoer
. .. _ _
EXAMPLE 4:
Agglomerated pea flour.
70 lb of a pea flour consisting of 25% protein was charged to a
treatment chamber as in Example l.
12 lb. of water was sprayed into the flour as in Example l(The
amount of water added represented 17~ of the flour by weight).
The material was heated to 185F and dried under Yacu D to 120F., as
in Example l.
The resulting material had a bulk density of 60 lb/ft3, was very
light golden brown in colour, and had no pea flavour or bitterness.
E~'~LE_5
An admi:;ture of a pea protein c~ncentrate ~n~i a starch (a snack food
mixture).
50 lb. of a ~ea protein concentrate containing 50~ pro~ein, and
50 lb. of a pea starch containing 80% starch and 5% pr~tein, was charged to
a treatment chamber as in Example 1. ~Total weight was 100 lb.)
ln lb. o~ water was sprayed into the mixture, and the mixture was
agglomerated, heated and dried, as in Example 2. The amount of water added
represents 20% of the pea protein concentrate in the admixture. The results
obtained are shown in Table 4. The product was ground and sized and was used
to make a snack product, as in Example 12.
T~BLE 4
.. _ __ _ j _
Moisture Protein Bulk Particle Pea Bitterness Colour
ldb/ft3tY Size Flavour
.. _. . ._ . _ _ . . .
50/50 9C~ above None None Very light
Concentrate/ 9.45 29.24 58.5 100 mesh golden
Pea Starch yellow
__ _ . ~ _ .__ _ _ __
EXAMP~E 6:
An admixture of pea concentrate and other foodstuffs: ~a breakfast
cereal admixture).
A mixture of the following ingredients was prepared:
50% pea protein concentrate - 40 lb.
Corn flour - 10 Ib.
80~ pea starch - 40 lb.
Sugar - 8 lb.
Malt - ~ lb.
Salt - ~ lb.
TOTAL - 98 3/4 lb.
The mixture was charged to a treatment chamber, as in ~xample 1, and
8 lb. of water was sprayed into the mixture. (The amount of water added
represented 20% by weight of pea concentrate present in the admixture).
The mixture was the~ agglomerated, heated, and dried as in Example 1.
The resulting product was dense, light in colour, with no residual pea
flavour or bitterness~ The product was ground and sized and used to
make a ready to eat breakfast cereal as in Example 13.
2L~
An adm~ixture of pea concentrate and other foodstuffs (a meat extender).
The following admixture was prepared:
50% Pea Protein Concentrate - 70 lb.
50~ Soya Flour - 25 lb.
Hydrol~ed Vegetable Protein - 5 lb.
TOTAL 100 lbs.
The rnixture was agglornerated, heated and dried as in Exarnple 1.
20 lbs. of water was used which represents approximately 20%
of the pea concentrate and soya flour in the mixture.
The agglomerated product was ground and sized, and used to make a
meat produc-t as in Example 11.
~he ground product was dense and had no pea-like flavour or
bitterness.
EXAMPLE 8:
An admixture of pea protein concentrate and other foodstuffs
(a beverage product)
The following beverage type admixture was prepared:
Skim Milk Powder - 20 lb
Sucrose - 12 lb
Dextrose - 4.5 lb
Vegetable gum - Q.5 lb
Cocoa powder - 3.5 lb
53,0 Pea protein
concentrate - 8.0 lb
48.5 lb
This admixture had a noticeable raw pea-like flavour and a bitter taste.
To this mixture was added 1~2 lb of water, in the form of a spray, which
quantity represents approx. 20% of the pea protein concentrate in the
admixture.
-- 1. S.l --
The admixture was consequentlY agg]omerated, heated, and dried as in
Exam?le 1. .~fter drying, 8 oz. of chocolate colour and fiavour, and 1 oz. of
vanillin ~ere added to the agglomel-ated admixture.
The product ~as then ground and sized, and used to prepare a beverage
drink by mixing the dry product with water.
The product dispersed readily in water, and the resulting beverage had
a rich chocolate-milk like flavour, and had no pea-like flavour or bitterness
when compared with the original unagglomerated admixture.
The protein content of the dry, agglomerated beverage mixture was 23%.
,7~
- 16 -
E,~LES OF SECON~ARY FOOD PRODUCTS MADE ~SING PR~DUCTS OP TXE PROCESS:
EXA.b~PLE g:
A cookie product:
The product of the process of Example 1 was blended with the following
ingredients and used to make a cookie dough:
Agglomerated 50% Pea Protein Concentrate - 7~ lb.
C2ke Flour - 7~ lb.
Liquid Eggs - 2 lb.
Granulated Sugar - 5 lb.
Brown Sugar - 5 lb.
Vegetable Shortening - 8 lb.
Baking Powder - 5 07.
Lemon Flavour - 4 oz
The dough was then extruded into 1 oz. buttons using a wire-cut
cookie machine, and baked at 400F for 10-12 mins. in a conventional
oven.
The resulting cookies were crisp and crumbly, and had no detectable
pea-like flavour or bitlerness. The protein content of the cookies
after baking was 14%.
EXAMPLE 10.
A hamburger roll product (a bread type product).
25% of the flour in a basic hamburger roll formula was replaced
with the ~roduct from E~ample 1, and the formula ingredients formed
into a dough.
The dough was formed into rolls and baked in a conventional manner.
The baked products were moist, had a light, open te~ture a light golden
yellow colour, and no pea-like flavour or bitterness.
The baked products had a protein content of 14-16~, and were
analyzed to be an excellent source of protein.
- 17 -
E~'T.~
A meat product.
The product admixture of Example 7 was added to ground beef in the
following manner:
Agglomerated Admixture (Example 7) - lC pts.
Ground Beef - 90 pts.
Water - 10 pts.
110 pts.
The mixture was blended well in a meat grinder, formed in~o patties
and fried.
The resulting fried meat product was moist and tender, and had no
pea~like flavour or bitterness.
EXAMPLE 12
A protein snack food product.
The agglomerated product of Example 5 consisting of an admixture
of 2ea protein concentrate and pea starch, was cooked and extruded
in a conventional extruder, and formed into an expanded snack food.
The resultins product was seasoned with vegetable~ oil, salt, and
various flavourings, and was light and very crisp, with no residual
pea flavour or bitterness.
The~protein content of this product was 24~.
EXAMPLE 13:
A protein breakfast Cereal Product.
The agglomerated product of Example 6, consisting of an admixture of
pea protein concentrate, corn flour, pea starch, sugar, salt, and malt,
was cooked and extruded in a conventional cereal extruder and formed into
pellets. These pellets were then formed into flakes by passing the
pellets between sheeting or flaking rollers. The flaked product wzs
then dried and toasted in a conventional oven to form a ready to eat
breakfast cereal product.
The cereal product was light and crisp, had no pea flour or bitterness,
and had a protein content of 22~o
~:IL1827~
- 18 -
EX~PLE 14:
A Protein Pasta Product.
20 pts. of a 60% pea protein concentrate from Example 2, was blended with
80 pts. of a semolina flour.
45 pts. of water was added to form a wet granular mixture, and the wet
mixture was extruded into various pasta forms such as macaroni, spagnetti,
and noodles, etc., and dried to a moisture content of 4%, using
conventional pasta equipment.
The product was then cooked in boiling water to form a ready to eat
pasta product.
The cooked pasta exhibited reduced stickiness and pastiness, had no
pea-like flavour or bitterness, was moist and turgid, and had a desirable
texture, characteristic of such products.
The dry pasta forms had a protein content of 22~%.
EXAMPLE 15:
A Protein Candy Product.
The agglomerated admixture of Example 5, consisting of 50% pea protein
concentrate blended with pea starch was used to make a candy bar product
as follows:
90 pts. of agglomerated admixture ~Example 5) was blended with 9 pts.
sugar and l pt. flavouring.
This mixture was then cooked~extruded to form a crisp, aerated, expanaed
product, using conventional snack extrusion equipment.
The product was cut into pieces of appropriate length and the pieces
enrobed with liquid chocolate, to form a ready-to-eat candy bar.
"
EXAMPLE 16:
A Crouton product (a biscuit type product).
The product of the process of Example l, was blended with the
following ingredients, and used to prepare a Crouton or a biscuit
type product:
~ 7~:~
- 19 -
Wheat Flour - 114 lb.
Agglomerated Pea Concentrate(from
~xample 1~ - 40 lb.
Corn Meal 20 lb.
Corn ~lour - 10 lb.
Skim Milk Powde~ - 7 lb.
Soya Oil - 5 lb.
Salt - 4 lb
TOTAL200 lbs.
This dry mixture was formed into a dough by the addition of 60 lb.
of water, and the dough was cooked, extr~lded, and dried to fo~m a
light and crisp crouton product.
This product had no pea-like flavour or bittPrness and was suitable
to be used as a garnish for soups and salads.
The protein content of the product was 20%.
Example 17 - A Snack Product
The agglomerate of Example 1 was ground and sized to produce
a coarse material between 1300 and 700 microns in particle
size . 30 pts of this coarse fraction was then blended with
70 pts of corn meal of approx. the sa~e particle size, and the
resulting mixture was extruded to form a crisp expanded
product.
The mixture cou]d easily be extruded and had a good volume,
was ligh~ and very crisp, and was an acceptable product.
The protein content of this product was 21%.
