Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The present invention relates to gelled or thickened food
products and in particular to microbiologically stable products containing
edible proteinaceous solids in aqueous medium.
Compositions comprising particles or pieces of meat or
other edible protein solids in a gelled or thickened aqueous medium
are ~ell known, in both human and animal food contexts, for example as
brawns and meat-in-jelly or meat-in-gravy products. Such products,
however, are not ordinarily shelf-stable and can only be stored by
special measures, usually by sterilization within sealed containers, as
by canning.
According to the present invention there is provided a food
product comprising solid foodstuff, including particles or pieces of
proteinaceous tissue, in an aqueous medium, such as a gel or thickened
gravy, surrounding said foodstuff, the product having a moisture content
of 65-95%, a protein content of 6-20% and a fat content of 3-12%, and
being maintained under antimycotic conditions and microbiologically
stable by virtue of an acidic pH value not exceeding 4.5 achieved or
maintained by acid-producing micro-organisms.
The product preferably has a pH in the range 3.5-4.5 and should
be maintained under antimycotic conditions usually by the inclusion of
an antimycotic, for example sorbic acid compounds such as potassium
sorbate, benzoates such as p-hydroxy benzoate or a mixture of the two.
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I~ the past~ difficulties ha~-e been encountered in
forming stable gel co~figuration~ with co~entio~al gelling
age~ts at the low pH values employed in this i~vention for
securing stabilit~.
In accorda~ce with a further important aspect of this
i~ve~tion, a gel structure i9 formed by a gelling agent in a mix
containing a solid foodstuff including protei~aceous tiss~ue,
ferme~table substance a~d moisture at a pH value above 4.5 a~d
the compositio~ is thereafter subjected to acid-produci~g fermentatio~
u~til its p~ value is 4.5 or below, especially in the ra~ge
3.5-4-5. -
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~his.tèc~ique of forming a~ aqueous mIx co~tai~ing
ed.ible protei~ tissue at a pH above 4.5 aDd subsequently
a¢hisvi~g micro-biological stability by fermentatio~ with
a¢id-producing orga~isms is ~ot, however, confined to products
having a rigid gel matrix. It ca~ also be employed more
generally to obtain products of the type, for example, of meat
i~ gravy. I~ these cases, a gelling age~t or thic~e~er may be
prese~t to provide a thicke~ed gravy or ~uch age~ts ma~ be
20 : completel~ absent. ~his procedure has the adva~tage that it
ca~ be carried out, without adaptation, in the same pla~t as
is employed i~ the production of gel products as described
above.
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Accordingl~, the method of this invention ca~ be
broadly defined a~ formi.ng a mix containi~g particles or pieces
of edible proteinaceous tissue, a~d preferably also fa~ and . -:
moisture in the abo~e defined proportions, including fermentable
~ubstance and having a pH value above 4.5; and thereafter
. subjecti~g the mix to acid-producing fermentation until its pH
~alue is 4.5~ or below and a microbiblogicPlly stable compositi~n
i~ produced.
I~ most cases where a gel i8 required, the freæhly
prepared m~x and the de.sired acid-producing microorganisms
.are filled into packaging containers and subsequentl~ incubated
in the contai~erY. When a gravy product is being made, howe~er,
or when a low temperature thermoreversible gel system i8 emplo~ed, --
- the mix can be ferme~ted in bulk and held at the incubation
.temperature until it is packaged.
~ uitable gelling agents include polysaccharide gelling
age~ts such as pectic substances, alginates, guar gum,carrageenan
and carob ~m, alæo starches and gelling agentæ of microbial
~ origin, such as microbial alginates and xanthan gum.
Proteinaceous gelling agents such as gelatin can also be used,
bub preferably not solel~ protein~ of the casein group.
~he mix may contain a source of calcium or other
acceptable div~lent metal ions, more especially for nutritional
.rea~ons or where such io~s are nseded to as~ist i~ the formation
of a good gel structure. The necessity for a~ exogenous source
of calcium-ions will depend on the gelling agent or agents used,
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1~537
the ~ature of the ingredie~ts and nutritio~al requirements.
Pectic substances employed i~ this invention are
preferably pectates or pecti~s having a degree of esterification
(D.E.) below 2~/o. Crude natural sources of pectins can be employed,
especially when their D.E. has been reduced, chemically or
` enzymatically, to below 20/o.
Citrus peel is a readly available source of pectins
and in this specification the expression 'treated citrus peel'
refe~s to citrus peel that has been comminuted and its D.E.
reduced below 2c~h by treatment with alkali or enzymes or by
promoti~g the action o~ en~ymes naturally contained within
th peel. Where a rigid gel is desired it is preferable to
include a source of calcium io~s and sequestrant such as sodium
tripolyphosphate, tetrasodium pyrophosphate or citric acid.
As proteinaceous ti~sue in the product of this
invention may be used, and by thi~ term is thus meant to be
` iucluded, an~ edible, solid, ordinarily insoluble protein
sue9 notably traditional meats, i~cluding fish or poultry,
offals, other animal protei~ sources such as dried greaves,
vegetable protei~ materials and structured or textured proteins,
~eaty materials may be pasteurized or sterilized, as may be
required by current food regulations or a~ demanded in achieving
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desirable microbiological safety ~tandards.
~part from the proteinaceous material, or other
solid foodstuff, fat moiæture and ~elling agent, the product
will usually contain residual ferme~table carbohydrate, a~d
may also contain vitamins or other nutritional supplements, -
¢olouring agents, antioxidants, antimycotics, preser~atives
or other additives.
In putting the invention into practice, a solution
may be prepared with desired amount of water and containing
the gelling agent, any necessary calcium or other metal ion,
~equestrant and fermentable substances additional to aI~y already
present in the other ingredients such as fermentable carboh~drate,
e.g. glucose or lactose, and optionally a~ organic nitrogen
source, and preferably also a~ a~timycotic. ~he solution may
be hea~ed to dissolve the soluble substances, but should the~
be cooled before a c~lture of an acid producing micro-organism
i8 added. Preferred micro-organisms are homo-fermentative
la¢tic acid-producing bacteria such as ~actobacillus
Casei, ~. ~ul~aricus~ Stre~tococcus lactis and S. thermoPhilus,
either singly or in any combination.It has bee~ found most
convenient to add the micro-organisms in the form of a~
i~oculum, in a quantity depending on the time necessary for
fermentation to the final pH and on the strain of micro-
organisms used. The quantity will most usually be in the ran~e
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of 1-10% b7 weight of the total composition as packed.
Other forms of cultu~for example freeze-dried starter cultures,
ca~ also be used.
~he solution, which will ordinarly have a pH in
the regio~ of 6, is then mixed with the solid ~oodstuffs~
which may be a previously prepared a~d pasteurized mix of
meats or meat by-products, but may also include or consist
of vegetable protein i~ a suitably prepared from. ~he latter
need not be pasteurized in the manner necessary in the case
of meats. ~he protein materials may be finely divided into
particles, for example by grinding, b~t more usually will be
in the form of minced or chopped pieces which, at least in
the case of pasteurized meat chunks, are preferably not larger
tha~ ~.0 cm3. This limit is less significant in the case of
sterilized materials or vegetable protein materials such as
textured vegetable protein, but the pieces should not be larger
than is convenient for filling t-he containers to be employed or
for acceptance by the consumer.
When the solution of gelling agent and the inoculum
have been mixed with the solid proteinaceous materials, the
composition is subJected to m cubation conditions. ~he gelling
agent will form a gel structure throughout the product under
the relatively neutral pH conditions prevailing in the earl~
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of incubation, but as incubation proceedq the micro-organisms
will bring about a reduction in p~I ~alue until st~bility is
reached at a pH value of 4.5 or less without loss of the gel
structure. ~he product may be packed into sealable containers
before incubation or, when a thermo-reversible gel is pro~uced,
it may be incubated in bulk at a temperature above the gel point
and packed before cooling. Gravy type products can also be
fermented in bulk. The resulting product will usu~lly contain,
and indeed preferably contains, viable acid-producing organisms,
and can be stored for long periods at ordi~ary temperatures.
I~ the preferred embodiments of the prese~t process,
a sequestering agent, antimycotic, colouring agent a~d glucose
ma~ be added to cold water and dissolved while being heated to,
for example, 70 - 90C whereupo~ gelling agents such as treated
citrus peel a~d guar gum are added with vigorous agitation.
~he mixture is then cooled to ~5 - 4~C before the acid-producing
fermentation inoculum is added.
Alternatively, the sequestering agent may be dissolvèd
in water and glucose and, if desired, a~ organic nitrogen source
added and-dissolved. ~he temperature of the liquid i9 raised,
for example to 70 - 90C a~d the gelling agents such as treated
citrus peel and guar gum are added with vigorous agitation.
~he mixture is then partially cooled before the addition of
pot~s~ium sorbateg colouring agents as desired, and a~ acidic
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1068537
fermentation i~oculum Or lactic acid-producing bacteria, e.g.
. casei or S. lactis.
~he gravy mix prepared by either of these alternative
procedures is added to a previously prepared and pasteurized or
sterilized meat mix. ~he resultant mixture may be packaged in
tra~sparent plastic re-sealable containers before being i~cubated,
for example at 30C for 12-24 hours.
A further alternative is for the inoculum to be added
bo the mixed meats after they have been mixed with the gravy.
When proceeding in this way, on may be able to make use of the
temperature difference betwee~ the meats and the gravy to effect
so~e of the necessary cooling.
~he products prepared in this way ~ay be found to
possess a good meat-in-jelly appearance with a fresh meaty
aroma. ~he food is highly acceptable to pet anlmals.
~he following examples illustrate the practice of
this inve~tio~. All perce~tages are b~ weight unless the
context otherwise requires.
Example 1
~his example illustrates the preparation of a stable
low pE7 high Awohunky ~eat in aelly food product.
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~ ripe, luns and musclè meats were comminuted by
passage through a mincer fittèd with a 1.0 cm plate and four-
bladed cutter. ~he meats were mixed in the xatio 44:40:16 of
tripe:lung:muscle meats and the muxture was boiled for 20 min
at 100C
A gravy was prepared to the following formulation:
Water ~Z-54
Sodium tripolyphosphate 0.5
Glucose 2.8
Potassium sorbate 0-4
D~estuff As desired
Guar B
~reated citrus peel 0.93
Inoculum 1.90
~he sodum tripolyphosphate, glucose, potassuim
sorbate and dyestuff were added to the water, and the mixture
was heated to 70C with agitation. ~he guar B and treated
peel were added with ~igorous agitation and the temperature
was increased to 80C. ~he resultant mixture was cooled to
35a before the addition of the inoculum which was a 20IH
culture of ~. casei.
- ~he gravy was added to the meat mix in a meat:
~ravy ratio of 70:30 and mixed well before being packaged in
tran~pare~t plastic pots with resealable lids. ~he pH of the
mix~ure was 6.4.
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~68537
~he pots were placed in an incubator at 30C for ~4 hours.
During the initial part of this period, i.e. 1-2 hours,
the io~ic gel structure formed. Only subse~uently did the
viable inoculum reduce the pH of the system ~o 3.8 - 4.2 by
conversio~ of the added sugars to lactic acid. ~he gel system
was stabilized against sy~eresis b~ the guar gum.
~ he inoculum was prepared b~ growing a pure c~ture
of I~acto-bacillus casei in MRS broth for a period of 12-20 hours.
~ he product possessed a very attractiv~ appearance
with discrete chunks of meat in the jelly matri~. It appeare~
very similar to traditional c~nned aelly meat pet food products.
Exa~ple 2
~ hi5 example demonstrate~ the production of a
microbiologically stable brawn-like product.
~ meat mix was prepared as in Example 1 except that
(a) the meats were put through a 4.0 mm plate, (b) equal ratios
of lung a~d muscle meats were used, and (c) the meats were boiled
in the presence of 0.4% potassium sorbate.
` A grav~ was prepared to the following formulation:
t
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- Water ~ 90.64
Sodium tripolyphosphate 0.50
- Glucose 2.80
~reated citrus peel 0.93
Guar gum 0.9
Po~assium sorbate 0.4
Dyestuff ~s desired
Inoculum ~.80
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~068537
The gravy was prepared as degcribed i~ Example l.
~he inoculum was a culture of ~. bul~aricus prepared as
described for I~ casei in Examplel.
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~he meat and gravy mixes were combined in the ratio
52:48 and the resultant mix packaged in plastic tubs of the t~pe
conve~tionally used to hold margarine. ~he tubs were incubated
for 24 hours at 30C.
~he product exhibited a pH of 4.0 and a brawn-like
appearance. It waR stable at ambient temperature against any
microbial attack.
~ he contal~er can serve either as a re-sealable
supply vessel of the food ar as a disposable food dish.
~ his Example demonstrates the use of anothex gel
system normally unstable during formation at acid pH values.
A ~olution of 20/o spray dried skimmed milk solids
in water was prepared. To 3000 ml. of this solution at 80C
were added 6.0 g of carrageena~, 3.0 g of potassium -~orbate,
~ 27.0 g of ~otassium chloride and colouring agents. These
components were dissolved and then 600 g of cooked meat
chunks were added. ~he whole mixture was cooled to 68C
before the addition of 5.0 ml of a viable suspen~ion of ~.
ca~ei i~ MRS broth. The inoculum was mixed in and the
mixture poured into suitable tran~parént containers.
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106853~7
~he containers were then rapidly cooled to about 40C before
bein~ put into an incubator at 3C for 12-15 hours.
The product had the appearance of meat chunis
in a cloudy opa~ue gel system. The pH of the product was 4.0 and
it possessed a meaty and milky aroma. It was highly acceptable
to pet animals especially cats.
Exæmple 4
~his Example shows the use of an alternative ionic
gel system.
10` A high ~iscosity alginate (grade IH7) was used as
in Example l in place of the treated peel at 5CP~ of the level
of treated peel, i.e. 0.5%. ~he product has the same appearance
as that described in Example 1.
~x~nple 5
~his Example demonstrates the use of a thermal
setting gelling agent in the process of this invention.
Calcium and phosphorus are included at desirable additional
levels. ~he calcium doe~ not here play any part in the gel
system.
Meats were prepared a~d cooked as described i~
Example 2.
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1068S37
A gra~y was prepared to the following formulation:
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Calcium Phosphate (Ca3(P04)2) 0~8
Gelatine 7-5
Glucose 6.0
Potassium sorbate 0.4
Erythrosine solution . 0 5
Caramel 0.75
Inoculum (~ Casei) 2.0 (of total
composition as
- packed)
Water to l00%
The gravy w~s prepared by dissolving all the
- in~redients in water, heating gently to dissolve the gelatine,
and cooling the mixture to 40 - 45G before addi~g the inoculu~.
~he grav~ ~as added to the meats in a 70 : 30 meat/gravy ratio~
well mixed and the composition was packaged i~ reseqlable
containers prior to incubation at 30C for 24 hours.
~he product had a pH of 4.3 a~d the ~ollowing
analy~
%
- - Mixture 8~.0
Protei~ ll.5
~at 2-5
Ash -9
% acidity - 1.77
~he gelatine gel was tough and rubbery and the product
Dxhibited a ~ery pleasing apperance
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Example 6 1~8S37
~y using an inoculum e.g. of ~. buI~aricus with
a highergrowth temperature, i.e. 42C~the above Example ~ can
be adapted to fermentation in bulk prior to packaging, the
gel being allowed to set on cooling in the individual containers.
Example 7.
~ his example illustrates the use of dry ingredients
in the formulation.
A grav~ is prepared according to the following
formulation:
` ~ of total Product
Sodum tripolyphosphate 0.25
~reated peel 0.5
Guar gum
~5 Caramel 1.5
Erythrosine solution 0.5
Potassium sorbate 0.4
Glucose (e.g. ~rudex) ~.0
Org~nic nitrogen source 0.5
(e.g. Corn Steep Liquor)
Water ~ to 75.0
only half of the water is used i~ gravy preparation.
After preparation of the gravy as described previously
the remaining cold water is added, ~ollowed by the required amount
of dried greaves i.e. 25% of the total product. ~he additional
of cold ingredie~ts at this stage lowers the temperature of the
mixture to 30 - 40~ and he~ce avoids the necessity.
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1~68537 `
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Of an additional cooling step prior to additional o~ the
inoculum (3%). All ingredients are then throughly mixed
prior to packaging and incubation at 30C ~or 24 hours.
After 24 hours the pH of the mixture had falle~
to PH 4.2.
Example 8
The following is an e~ample o$ a meat`and cereal
product.
Conditioned sheep lung which had been minced through
a 1.0 cm plate was mixed with~
Maize Grits 15% ( based on the wèigh~ of lung)
Wheat`Feed 5% ( based on the weight of lu~g)
~ e meat and cereals were cooXed at 121C for 50
minutes to produce a firm 'loaf~ structure.
A gra~y was prepared according to the formulation:-
- -` h of Grav~
,' Treated citrus peel 1.0
Guar gum 1.0
` ~ Glucose 7.0
~otasslum sorbate 0.4
Sodium tripolyphosphate 0.5
Caramel 1.5
Erythrosine solution 0.5
Water Bala~oe.
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~ he meat and cereal~ were formulated with gravy
in a 60:40 ratio and the mixture cooled to 35C before
inoculation with ~. bul~aricus suspension (3.CP/c of total
pack). After packaging a~d incubation, the product had a
p~ of 3.9 and a firm 'loaf' type structure with a cereal
aroma.
Example 9
~ his example demonstrates the preparation of a
greav,y product.
3.5 kg of conditin~ed sheep lung was minced through
a 3.0 mm plate using a Hobart mincer fitted with a four bladed
: cutter. ~he minced meat was cooked at 121C fo~ 50 mi~s.
A gravy was prepared accor~ing the following
for~ulatio~:-
- . . ~ of ~ravY
,, ' G~uax gum ' ' 1.0
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`~ Glucose (Trudex) 8.0
Caramel . 1.5
Erythrosi~e 801ution 0. 5
potassium sorbate 0.4
,~ Emulsif~ing age~t (Tween 80) 1.0
. Artificial flavour 10.2
Water Balance
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106~537
~ he gra~ was prepared as descrlbed pre~iou~ly.
Meats a~d gravy were mixed together in a 70;30 ratio and cooled
to 35C prior to inoculation with a 20 IE old ~S both suspension
of ~. Casei (3% of the total mix). The inoculum was mixed in
well a~d the mixture packaged in 'Saran' (Trade Mark) pouches,
sealed and incubated at ~0O for 24 hours.
~ he final pH of the product was 4.2 and it possessed
a mince meat in thick, rich gravy, type of appearance.
Example 10
~his example demonstrates the use of a starch gravy.
A ~ravy Sheep lu~g was prepared as described above. A gravy
was prepared to the followin~ formulation:-
/0 of Grav~
: aa3 (P04)2 0.8
Glucose 6.0
*P - OE ~enzoates 0.5
Erythrosine æol. 0.5
Caramel 1.5
`, Modified St~rch (Col-~lo) 5.0
Water. Balance
I~ this context the calcium phosphate was added
as a ~utritio~al supplement.
* P - OH ~enzoates = a 3:1 o~ methyl and propyl
substituted benzoate~.
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~ he grav~ was added to the cooked meats in~eratio of 30:70 and the mixture cooled to 35C. The i~oculum
at a level of 2% of the total pack was added a~d lnixed well
~ ne resultant mixture was packed into plastic tubs ar~d
5 i~cubated at ~0C for 20 hours.
~ he product had a pH of 4.1 and a meat in gra~
appearance.
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