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Patent 2684721 Summary

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(12) Patent: (11) CA 2684721
(54) English Title: METHOD OF MAKING FRESH CHEESE WITH ENHANCED MICROBIOLOGICAL SAFETY
(54) French Title: METHODE DE PREPARATION DE FROMAGE FRAIS AVEC SURETE MICROBIOLOGIQUE AMELIOREE
Status: Granted
Bibliographic Data
(51) International Patent Classification (IPC):
  • A23C 19/097 (2006.01)
(72) Inventors :
  • KOERTNER, MARY REGINA (United States of America)
  • LEWANDOWSKI, VICKIE JANE (United States of America)
  • MEHNERT, DAVID WEBB (United States of America)
(73) Owners :
  • KRAFT FOODS GROUP BRANDS LLC (United States of America)
(71) Applicants :
  • KRAFT FOODS GLOBAL BRANDS LLC (United States of America)
(74) Agent: OSLER, HOSKIN & HARCOURT LLP
(74) Associate agent:
(45) Issued: 2013-05-28
(22) Filed Date: 2009-11-05
(41) Open to Public Inspection: 2010-05-14
Examination requested: 2010-01-15
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
61/114,633 United States of America 2008-11-14

Abstracts

English Abstract

Described herein is a high moisture, preserved cheese product having enhanced microbial food safety and methods of making the high moisture, preserved cheese product. Enhanced microbial food safety is achieved by using a combination of organic food preserving acids, a nisin component and an enzyme.


French Abstract

Description d'un produit de fromage de conserve à humidité élevée présentant une innocuité alimentaire microbienne améliorée et des procédés de fabrication du produit de fromage de conserve à humidité élevée. On obtient l'innocuité alimentaire microbienne améliorée en utilisant une combinaison d'acides de conservation des aliments, de la nisine et un enzyme.

Claims

Note: Claims are shown in the official language in which they were submitted.




CLAIMS

What is claimed is:


1. A preserved high moisture cheese composition comprising:
cheese having at least about 40 weight percent moisture;
a preservative blend comprising at least one organic food preserving acid or
its
food grade acceptable water soluble salt, nisin, and at least one enzyme which
inhibits
gram positive bacteria, gram negative bacteria, yeasts and molds,
the preservative blend of organic preserving acid, nisin component and enzyme
being in an amount and the ingredients of the preserving blend being in
relative
amounts to provide the preserved cheese composition which will have less than
1 log
cfu/g of pathogenic gram positive and gram negative bacteria for at least
about 7 days
when stored at 55°F immediately after production of the preserved
cheese composition.

2. The preserved cheese composition of claim 1 wherein the pathogenic bacteria

are Listeria monocytogenes, Salmonella, E. colli, and Clostridium botulinum.


3. The preserved cheese composition of claim 1 wherein the preservative blend
includes citric acid or the water soluble salt of citric acid and sorbic acid
or the water
soluble salt of sorbic acid.


4. The preserved cheese composition of claim 3, wherein the cheese is queso
fresco.


5. The preserved cheese composition of claim 3, wherein the cheese is selected

from the group consisting of ricotta, mozzarella and cottage cheese.


6. The preserved cheese composition of claim 1, wherein the preservative blend

includes about 900 parts by weight, based upon the weight of the blend, citric
acid or




the water soluble salt of citric acid and 500 parts by weight, based upon the
weight of
the blend, sorbic acid or the water soluble salt of sorbic acid, 210 parts by
weight, based
upon the weight of the blend, nisin, and 12 parts by weight, based upon the
weight of
the blend, enzyme.


7. The preserved cheese composition of claim 1, wherein sorbic acid or its
water
soluble salt comprises about 0.1 weight percent, based upon the dry solids of
a cheese
curd which is a precursor of the cheese, citric acid or its water soluble salt
comprises
about 0.18 weight percent, based upon dry solids of the cheese curd, nisin
comprises
about 0.0042 weight percent, based upon dry solids of the cheese curd, and
enzyme
comprises about 0.00024 weight percent, based upon the dry solids of the
cheese curd.

8. A method for preserving a high moisture cheese product, the method
comprising:
blending a curd precursor of the high moisture cheese and a preservative blend

comprising at least one organic food preserving acid or its food grade
acceptable water
soluble salt, nisin, and at least one enzyme which inhibits gram positive
bacteria, gram
negative bacteria, yeasts and molds, to provide a high moisture preserved
cheese
product having at least 40 weight percent moisture; and
aseptically packaging the high moisture preserved cheese product,
the preservative blend of organic preserving acid, nisin and enzymes being in
an
amount and the ingredients of the preserving blend being in relative amounts
effective
to provide the preserved cheese product with less than 1 log cfu/g of
pathogenic gram
positive and gram negative bacteria when stored for at least about 7 days at
55°F after
opening the aseptically packaged preserved cheese product.


9. The method of claim 8 wherein the pathogenic bacteria are Listeria
monocytogenes Salmonella, E. colli, and Clostridium botulinum.


10. The method of claim 8 wherein the preservative blend includes citric acid
or the
water soluble salt of citric acid and sorbic acid or the water soluble salt of
sorbic acid.

21



11. The method of claim 10 wherein the cheese is queso fresco.


12. The method of claim 10 wherein the cheese is selected from the group
consisting
of ricotta, mozzarella and cottage cheese.


13. The method of claim 8, wherein the preservative blend includes about 900
parts
by weight, based upon the weight of the blend, citric acid or the water
soluble salt of
citric acid and 500 parts by weight, based upon the weight of the blend,
sorbic acid or
the water soluble salt of sorbic acid, 210 parts by weight, based upon the
weight of the
blend, nisin, and 12 parts by weight, based upon the weight of the blend,
enzyme.


14. The method of claim 8, wherein sorbic acid or its water soluble salt
comprises
about 0.1 weight percent, based upon the dry solids of a cheese curd which is
a
precursor of the cheese, citric acid or its water soluble salt comprises about
0.18 weight
percent, based upon dry solids of the cheese curd, nisin comprises about
0.0042 weight
percent, based upon dry solids of the cheese curd, and enzyme comprises about
0.00024 weight percent, based upon the dry solids of the cheese curd.


22

Description

Note: Descriptions are shown in the official language in which they were submitted.


CA 02684721 2009-11-05



METHOD OF MAKING FRESH CHEESE WITH ENHANCED
MICROBIOLOGICAL SAFETY

FIELD
[00011 Described herein is a high moisture, preserved cheese product having
enhanced microbial food safety and methods of making the high moisture,
preserved
cheese product. Enhanced microbial food safety is achieved by using a
combination of
organic food preserving acids, a nisin component and an enzyme system.


BACKGROUND
[0002] Food processors have long felt the need for methods to prolong the
shelf life
of foodstuffs and/or increase microbiological stability of such foodstuffs. By
increasing
the amount of time a foodstuff is stable, processors can mitigate inventory
losses due to
spoiled foodstuffs. Prior methods, such as, the use of packaging,
preservatives, and/or
specific storage parameters (e.g., refrigeration) have been used to stave off
spoilage.
[0003] Bacterial contamination of foods is known to be responsible for
spoilage
and for the transmission of food borne illness. In particular, Listeria
monocytogenes has
been associated with such foods as raw milk, cheeses (particularly soft-
ripened
varieties), ice cream, raw vegetables, fermented raw meat sausages, raw and
cooked
poultry, raw meats (of all types), and raw and smoked fish. Listeria
monocytogenes is a
psychrotrophic food borne pathogen which is very widespread in the environment
and in
foods. The ability of Listeria monocytogenes to grow at temperatures as low as
3 C
permits multiplication in refrigerated foods.
[0004] Bacteriocins are antimicrobial peptides that are produced by bacteria
and
which have bactericidal action against closely related species. One of the
most
extensively characterized bacteriocin is nisin which is produced by a lactic
acid type
bacteria and which may be used to prevent growth of Gram-positive bacteria in
a wide
variety of different food products, particularly dairy products (see, e.g.,
U.S. Patent
Publication No. 2008/0152757; U.S. Patent 2,744,827; U.S. Patent 4,584,199;
U.S.
Patent 4,597,972; and U.S. Patent 5,527,505).



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[0005] Currently, most commercial refrigerated unaged, high moisture cheese
products with relatively high pHs (e.g. above about 5.0) have a very limited
shelf life and
do not have secondary barriers to psychrotrophic pathogens. However, there
have
been efforts to enhance the microbiological safety of such cheese products.
Generally,
known methods to enhance microbiological safety in food products include
cooking,
adjusting water activity, adjusting pH, and/or using preservatives. However,
these
methods are generally expensive and therefore increase the cost of storing and

producing the foodstuff while, in some cases, diminishing the organoleptic
properties of
the food product.

SUMMARY
[0006] A high moisture preserved cheese product and a method of preserving a
high moisture cheese product is described herein. The high moisture preserved
cheese
product comprises a high moisture cheese and a preservative blend of: (i) at
least one
food grade organic food preserving acid or its food grade acceptable water
soluble salt
which can include citric acid and water soluble salts thereof and/or sorbic
acid and
water soluble salts thereof, (ii) a nisin component, (iii) and an enzyme
system which is
active against gram positive and gram negative bacteria as well as yeast and
molds,
and remains active to inhibit such bacterial in a pH range of 3.6 to 8.3. The
preservative
blend of organic preserving acid, nisin component and enzyme system is in an
amount
and the ingredients of such blend are in relative amounts to provide a high
moisture
preserved cheese product with less than 1 log cfu/g of pathogenic gram
positive and
gram negative bacteria for at least about 7 days when stored immediately after
its
production at 55 F, and preferably 45 F. In another aspect, the preserved
cheese
product is aseptically packaged immediately or nearly immediately after its
production
and the aseptically packaged preserved cheese product will have less than 1109
cfu/g
for at least 7 days if the aseptic package is opened just after packaging and
stored at
55 F, preferably 45 F. The preserved cheese product exhibits organoleptic
properties
similar to the same non-preserved cheese for at least 7 days after its
production and
storage which is open to the atmosphere and is at 55 F, preferably 45 F. The
animal

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and fungal enzyme is commercially available as a blend under the name of Sea-i
from
BIENCA S.A, Avenue Reine Astrid 262, Seneffe 7180, Belgium. The method for
preserving the high moisture cheese product, includes mixing the preservative
blend of
the at least one organic food preserving acid which can include citric acid
and/or sorbic
acid, a nisin component, an enzyme system into curd which is a precursor to
the high
moisture cheese product. As with the preserved cheese product aspect of the
invention, in the method described herein, the preservative blend of organic
preserving
acid, nisin component and enzyme system is in an amount and the ingredients
are in
relative amounts effective to provide the high moisture preserved cheese
product with
less than 1 log cfu/g of pathogenic gram positive and gram negative bacteria
when
stored for at least about 7 days at 55 F, and preferably 45 F, with the
preserved cheese
product exhibiting organoleptic properties similar to the same high moisture
cheeses.
As described herein a "high moisture cheese product" has a moisture content of
at least
about 40 weight percent water. Additionally, aseptically packaged means
packaged to
the exclusion of microorganisms other than those carried by the packaged
product,
such as the preserved cheese product.
[0007] In one important aspect the food preserving acid is a blend of citric
acid and
sorbic acid. In an important aspect the blend of citric and sorbic acid is
combined with
the enzymes and nisin component such that the blend has 500 parts by weight,
based
upon the weight of the blend, sorbic acid, 900 parts by weight, based upon the
weight of
the blend, citric acid, 210 parts by weight, based upon the weight of the
blend, nisin, 12
parts by weight, based upon the weight of the blend, enzyme system.
[0008] In yet another important aspect, sorbic acid or its water soluble salt
comprises about 0.1 weight percent, based upon the dry solids of a fresh
cheese curd
which is a precursor of the fresh cheese, citric acid or its water soluble
salt comprises
0.18 weight percent, based upon dry solids of the cheese curd, nisin comprises
about
0.0042 weight percent, based upon dry solids of the cheese curd, enzyme system

comprises 0.00024 weight percent, based upon the dry solids of the cheese
curd.



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DETAILED DESCRIPTION
[0009] The high moisture preserved cheese product described herein has and
enhanced microbial food safety such that the combination of an organic acid,
nisin and
enzyme system provide a preserved cheese product that retains the taste and
organoleptic properties of the same cheese that does not have the combination
of acid,
nisin and enzyme system, but will provide a product with less gram positive
and gram
negative bacteria as described herein than the same cheese preserved with the
same
weight percents of food preservative acids, nisin and where weight percent of
the
enzyme system is replaced by sorbic (e.g. replacing enzyme system) and citric
acid
(replacing enzyme system).
[0010] The method described herein may be used in the production of any high
moisture, cultured dairy product, such as, but not limited to, fresh Mexican
cheeses,
such as queso fresco, mozzarella cheese, ricotta cheese and cottage cheese.
The
cheeses produced by the methods described herein advantageously enjoy
microbiological safety after removal of the preserved cheese from its
packaging,
rendering the cheeses more microbiologically stable over a longer period of
time.
[0011] Queso fresco or queso blanco is a creamy, soft, and mild unaged white
cheese. The name queso blanco is Spanish for "white cheese", but similar
cheeses are
used and known throughout the world by different names. Queso blanco is a
fresh and
slightly salty cow's milk cheese (which salts can include CaCl2, whereas queso
fresco
may be made from a combination of cow's and goat's milk. Both of these cheeses
will
be referred to herein as queso fresco cheese.
[0012] Queso fresco cheese is made by pressing the whey from rennet coagulated

cheese curd. Queso fresco generally has a high water activity of over 0.89 and
a high
pH ranging from about 5.25 to over 6Ø A typical queso fresco cheese has a
good melt
restriction. That is, when the cheese is exposed to moderate heat treatment
such as
boiling or microwave for a short period of time, it should remain in good
shape and not
melted unlike most other cheese products. Queso fresco, like other high
moisture, fresh
cheeses, if contaminated, will support growth of microbial contaminants in a
matter of
days without the addition of preservatives. Specifically, because of its
relatively high

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pH, queso fresco is susceptible to the growth of bacterial pathogens such as
Gram-
positive bacteria, including Listeria monocyto genes and Clostridium botulinum
as well
as Gram-negative bacteria such as Escherichia coil 0157:H7 and Salmonella. In
order
to be considered microbiologically stable, the cheese should not allow the
inoculated
pathogenic bacteria to grow more than 1 log in cfu/g in at least one month
under
refrigerated conditions. Most commercial queso fresco products on the market
today do
not meet these criteria.
[0013] Generally, the high moisture dairy products described herein retain
desirable
organoleptic qualities while having inhibiting bacterial growth by virtue of
blend of at
least one organic food preserving acid which can include citric acid and/or
sorbic acid, a
nisin component and an enzyme system. For example most currently commercially
available queso fresco cheese products have a shelf life (not more than 1 log
cfu/g) of
not more than three days when stored at about 45 F, as compared to queso
fresco
cheese products preserved by the blend as described herein.
[0014] The bacteriocin nisin is produced by fermentation using the bacterium
Lactococcus lactis. Commercially it is obtained from natural substrates
including milk
and is not chemically synthesized. It is used in processed cheese production
to extend
the safe, usable life by suppressing gram-positive spoilage and pathogenic
bacteria.
Due to its highly selective spectrum of activity it is also employed as a
selective agent in
microbiological media for the isolation of gram-negative bacteria, yeast and
molds. Two
commercially available antimicrobials containing nisin are Nisalpin and
Novasinim (both
from Daniso A/S, Denmark). Typically, Nisaplin contains less than about 3.0
weight %
nisin, the remainder consisting of NaCl, proteins, carbohydrates and moisture.
When
referring to a nisin component herein the component not only includes nisin,
but also
other ingredients which include carriers, salts, protein and carbohydrates.
[0015] Nisin is an inhibitory polycyclic peptide with 34 amino acid residues
used as
a food preservative. It contains the uncommon amino acids lanthionine,
methyllanthionine, dehydroalanine and dehydro-amino-butyric acid. These amino
acids
are synthesized by posttranslational modifications. In these reactions a
ribosomally


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synthesized 57-mer is converted to the final peptide. The unsaturated amino
acids
originate from serine and threonine.
[0016] Sorbic acid is a preservative used to inhibit molds, yeast and fungi
in many
foods and beverages. Generally, water soluble food grade salts of sorbic acid
are
preferred for their water solubility.
[0017] Citric acid is a weak acid and preservative. Food grade citric acid
and its
water soluble salts may be used as a part of the preserved cheese product and
method
described herein and is recognized as a safe food additive.
[0018] Sea-i is an enzyme system sold by BIENCA S.A., Belgium. Sea-i has a

range of activity to inhibit both Gram positive and Gram negative bacteria, in
addition to
yeasts and molds. Further, the enzyme system Sea-i is activated when
hydrated, with
at least 20% free moisture, in the system in which it is used. Sea-i is
deactivated by
heat (in excess of 50C), pH (active in the range of 3.6 to 8.3), sanitizers
(in particular
oxidizing agents) or over the passage of time. Upon deactivation Sea-i
becomes
protein with no catalytic activity.
[0019] Sea-i inhibits metabolite production and has either a bacteriostatic
effect
(by extending the latency phase) or bactericidal effect (killing micro-
organisms)
depending on the initial contamination.
[0020] The blend of organic food acid, nisin and enzyme system may be added
individually or premixed and blended into the cheese making process, such as
blending
the acids, nisin and enzyme system into the curd precursor having at least 20
weight
percent moisture to the cheese product to provide a homogeneous mixture of
blend and
curd. In a preferred embodiment, the preservative blend is blended with the
curd after
the separation of the whey in order to minimize loss of the components of the
preservative blend. Following the blending of the acid, nisin, enzyme system
with the
curd, the curd and preservative blend are mixed so that the preservative blend
is
homogenously dispersed throughout the curd. Generally this mixing takes from
about 8
to about 10 minutes.
[0021] Advantageously, although the preserved cheese product described herein

remains microbiologically stable longer after opening or exposure to
microbiological

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contaminants, the cheese does not suffer from adverse organoleptic properties.
For
example, in conventional queso fresco cheese, it is desirable to prevent post-
process
acidification. If post-process acidification occurs, the acid produced by
natural
microflora during storage will result in rapid acidification of the cheese and
the
characteristic crumbly texture and melt restriction properties are lost and an
undesirable
fermented flavor will develop. By using the methods described herein, risk of
post-
process acidification is mitigated or eliminated by using a blend which
includes citric
acid, sorbic acid, nisin and an enzyme system such as Sea-i . Thus, the
methods
described herein can be used to produce a preserved queso fresco cheese that
may be
safely stored for an extended period of time after opening without losing the
typical
physical and organoleptic characteristics of queso fresco cheese.
[0022] A better understanding of the present embodiment and its many
advantages
may be clarified with the following examples, given by way of illustration.

Comparative Example 1: Preparation of Control Queso Fresco Cheese.
[00231 A queso fresco cheese without enhanced microbial stability was prepared
as
described hereinbelow. No antimicrobial compounds were added.
1. Add CaCl2 (0.01% of 45% stock solution, diluted in deionized water) to milk
in
vat;
2. Slowly heat milk in vat with agitation ¨ target about 88 F (range of about
86 to
about 90 F);
3. Add the pre-made starter culture at 2%;
4. Hold 15 min with agitation;
5. Add rennet (0.01% of 2x Chymax, diluted in deionized water);
6. Hold 40 minutes with no agitation;
7. Cut curd and heal for 10 minutes ¨ no agitation;
8. Slowly heat curd and whey to about 106 F over about 20 min ¨ with
agitation;
9. Hold for 5 minutes with no heat and no agitation;
10. Pump curd and whey to drain table, stir and drain whey (curd pH 6.2-6.5);
11. Let stand for 5 minutes;

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12. Pack cheese into individual packages/casings; and

13. Refrigerate the cheese.

[0024] The resulting cheese had a moisture content of about 48% and a pH
of about

6.3. The queso fresco was then stored at 45 F for six weeks, during which time
the

queso fresco was analyzed for bacterial growth, in particular Listeria,
Salmonella and

E.Coli at 45 F and 55 F. Bacterial growth exceeding 1 log CFU / gram was
considered

a failed test.



Table 1: Bacterial Growth in Queso Fresco Control at 45 F

Interval (Day) Listeria Salmonella E.Coli
0 _*
1 Pass Pass Pass

3 Pass Pass Pass
Fail Pass Pass
7 Fail Pass Fail

Fail Pass Fail
14 Pass

21 Pass
24 Pass

28 Pass
35 Pass
42 Pass

* Indicates not tested.

Table 2: Bacterial Growth in Queso Fresco Control at 55 F

Interval (Day) Listeria Salmonella E.Coli
0 _*
1 Pass Pass Pass

3 Fail Fail Fail
5 Fail Fail Fail

42

* Indicates not tested.



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Example 2: Queso Fresco with the Addition of Sorbic Acid, Nisin and Sea-i
[0025] Queso fresco was prepared in the same manner as in Example 1.
However,
after step 10 wherein the whey is drained from the curd, a premixed
antimicrobial blend
was added to the curd. The antimicrobial blend included sorbic acid, Nisaplin
and Sea-
le. Further, the blend included 7 parts Nisaplin, 5 parts sorbic acid and 6
parts Sea-i .
The blend was added to the curd, and the curd and blend were mixed for about 8-
10
minutes to achieve a homogenous dispersion of the blend throughout the curd.
In
particular, the curd and blend combination included 0.07% Nisaplin, 0.05%
sorbic acid
and 0.06% Sea-i . As with Example 1, the queso fresco was stored at both 45 F
and
55 F for six weeks, during which time the queso fresco was analyzed for
bacterial
growth, in particular Listeria, Salmonella and E.Coli at 45 F and 55 F.
Bacterial growth
exceeding 1 log CFU / gram was considered a failed test.

Table 3: Bacterial Growth in Queso Fresco with Antimicrobial Combination at 45
F
Interval (Day) Listeria Salmonella E.Coli

0
1 Pass Pass Pass
3 Pass Pass Pass
Pass Pass Pass
7 Pass Pass Pass
Pass Pass Pass
14 Pass Pass Fail
* Indicates not tested.

Table 4: Bacterial Growth in Queso Fresco with Antimicrobial Combination at 55
F
Interval (Day) Listeria Salmonella E.Coli

0
1 Pass Pass Pass
3 Pass Pass Pass
5 Pass Pass Fail
7 Pass Pass Fail

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Pass Fail
14 Pass Fail
* Indicates not tested.

Example 3: Queso Freso with the Addition of Citric Acid, Sorbic Acid, Nisin
and Sea-i0
[0026] Queso fresco was processed using the procedures of Example 2, but with
the addition of citric acid. The relative amounts of sorbic acid, Nisaplin and
Sea-ie
remained the same as in Example 2. Further, the overall percentage of sorbic
acid and
Nisaplin in the curd / blend combination remained unchanged. The blend
included 7
parts Nisaplin, 5 parts sorbic acid, 6 parts Sea-Ks and 9 parts citric acid.
The blend was
added to the curd, and the curd and blend were mixed for about 8-10 minutes to

achieve a homogenous dispersion of the blend throughout the curd. In
particular, the
curd and blend combination included 0.07% Nisaplin, 0.05% sorbic acid, 0.06%
Sea-is
and 0.09% citric acid. As with Example 1, the queso fresco was stored at 45 F
for six
weeks, during which time the queso fresco was analyzed for bacterial growth,
in
particular Listeria, Salmonella and E.Coli at 45 F and 55 F. Bacterial growth
exceeding
1109 CFU / gram was considered a failed test.

Table 5: Bacterial Growth in Queso Fresco with Antimicrobial Combination at 45
F
Interval (Day) Listeria Salmonella E.Coli

1 Pass Pass Pass
3 Pass Pass Pass
5 Pass Pass Pass
7 Pass Pass Pass
10 Pass Pass Pass
14 Pass Pass
* Indicates not tested.

Table 6: Bacterial Growth in Queso Fresco with Antimicrobial Combination at 55
F
Interval (Day) Listeria Salmonella E.Coli


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0
1 Pass Pass Pass
3 Pass Pass Pass
Pass Pass Pass
7 Pass Pass Pass
Pass Pass Pass
14 Pass Pass Pass
* Indicates not tested.

Example 4: Queso Fresco with the Addition of Citric Acid, Sorbic Acid, Nisin,
Sea-i
and an "Activated Culture"
[0027] Queso fresco was processed using the procedures of Example 3, but an
"activated culture" was added to the antimicrobial combination. In particular,
the
"activated culture" is a low acid, nisin producing culture as described in
U.S. Patent
Publication No. 2008/0152757. The relative amounts of each component of the
blend
included 7 parts Nisaplin, 5 parts sorbic acid, 6 parts Sea-i , 9 parts citric
acid and 1
part activated culture. Within the curd and blend combination, the Nisaplin
comprised
0.07%, sorbic acid comprised 0.05%, Sea-i comprised 0,06%, citric acid
comprised
0.09% and the activated culture comprised 0.01%.
Table 7: Bacterial Growth in Queso Fresco with Antimicrobial Combination at 45
F
Interval (Day) Listeria Salmonella E.Coli
0
1 Pass Pass Pass
3 Pass Pass Pass
5 Pass Pass Pass
7 Pass Pass Pass
10 Pass Pass Pass
14 Pass Pass Pass
* Indicates not tested.

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Table 8: Bacterial Growth in Queso Fresco with Antimicrobial Combination at 55
F
Interval (Day) Listeria
Salmonella
E.Coli
0
1 Pass
Pass
Pass
3 Pass
Pass
Pass
5 Pass
Pass
Pass
7 Pass
Pass
Pass
10 Pass
Pass
Pass
14 Pass
Pass
Pass
* indicates not tested.


Example 5: Microbial Stability of Queso Fresco at Refrigeration Temperature.
[0028] The microbial stability of the inventive cheese
from Example 3 above was
compared to the cheeses of Examples 2 and 4 under refrigeration conditions.
Two
pathogens capable of growing under refrigeration conditions were used. The
psychrotrophic pathogens included both Gram-positive (Listeria monocytogenes)
and
Gram-negative bacteria (Escherichia coh).
[0029] The inventive cheese sample of Example 3 and the
cheeses of Examples 2
and 4 were inoculated with L. monocytogenes and E. coil and were stored at 45
F for a
period of 5 weeks. The results of the growth of L. monocytogenes and E. coli
in the
cheeses at 45 F are summarized in Tables 9 and 10 below.


Table 9. Average Growth of L. monocytogenes in Queso Fresco cheese during
storage at 45 F
Treatment 0
3 5 Time (days)
7 14
Example 3 , 20
10 , <10
<10 <10
Example 2 <10
<10 <10
<10 <10
Example 4 <10
<10 <10
<10 <10

Values in the above table are reported in colony forming units (cfu) per gram
of cheese.


[0030] The data shows that the blends of Examples 2, 3
and 4 effectively inhibited
the growth of Listeria monocytogenes at refrigeration temperature.



12

CA 02684721 2009-11-05



Table 10. Growth of E. coil in Queso Fresco cheese during storage at 45 F
Time (days)
Treatment 0 3 5 7 14 21 28 35
Example 2 56.7 10 <10 <10 <10 <10 <10
Example 3 110 <10 170 <10 <10 <10
Example 4 <15 <100 <10 <110 <10 <10 <10

Values in the above table are reported in colony forming units (cfu) per gram
of cheese.


[0031] The data shows that the blends of Examples 2, 3 and 4 effectively
inhibited
the growth of E. coli at a refrigeration temperature of 45 degrees Fahrenheit.


Example 6: Microbial Stability of Queso Fresco at Abused Temperature.
[0032] The microbial stability of the inventive cheese from Example 3 above
was

compared to the cheeses of Examples 2 and 4 at a slightly abused temperature
(55 F).
The cheeses of Examples 2, 3 and 4 were inoculated with L. monocytogenes and
E. coil
and was stored at 55 F for a period of 5 weeks. Samples were taken for L.
monocytogenes and E. coli analysis periodically. The results are shown in
Tables 11
and 12 below.


Table 11. Growth of L. monocytogenes in Queso Fresco cheese during storage at
55 F
Time (days)
Treatment 0 3 5 7 14 21 28 35
Example 2 20 <10 <10 1766.7 349066
Example 3 <10 <10 <10 <10 9050 165275 708000
Example 4 <10 - <10 <10 <10 <7285 5093 <13030

Values in the above table are reported in colony forming units (cfu) per gram
of cheese.
[0033] The data shows that the cheese of Example 2 supported a rapid growth
of L.
monocytogenes noticeable on day 7 while the cheeses of Examples 3 and 4
effectively

inhibited the growth of Listeria monocytogenes at 55 F at least through seven
days.



13

CA 02684721 2009-11-05



Table 12. Growth of E. coil in Queso Fresco cheese during storage at 55 F
Time 'days)
Treatment 0 3 5 7 14 21 28 35
Example 2 56.7 30 50 606.7 6240
Example 3 110 35 <10 <15 <40 <2600 <3400 <850
Example 4 <15 <10 <10 <1 <500 <4800 <10 <130


Values in the above table are reported in colony forming units (cfu) per gram
of cheese.


[0034] The data shows that the cheese of Example 2 supported a rapid growth
of E.
coil noticeable on day 7 while the cheeses of Examples 3 and 4 effectively
inhibited the
growth of E. coil at 55 F at least through seven days.


Example 7: Sensory evaluation of the traditional Queso Fresco and Formulations
of
Examples 2, 3 and 4:
[0035] A formal consumer evaluation was performed in areas with a relatively
larger
population of Mexican Americans. The products were evaluated in several
categories
including general rating, purchase intent, flavor, texture, melting and
appearance. The
assessment results are shown in Table 13.



14

CA 02684721 2009-11-05



Table 13. Consumer sensory evaluation scores of Queso Fresco cheese

Category
Control Example 2
Example 3 Example 4
(no antimicrobial)

_
General ratings:
(
_ Overall opinion of Appearance (9 pt) _
7.23/7.86
7.61/7.77 7.42/7.82
7.53/7.82
Overall opinion (9 pt.)
7.08/7.57
7.19/7.17 _ 7.24/7.56
7.27/7.20
Expectation ("better or same" %)
82/96
93/87 _ 88/95
83/91
Flavor: Purchase intent (5 pt.)
3.86/3.8 1
3.96/3.39 3.97/3.62
4.01/3.55 -
Overall flavor liking (9 pt.)
6.91/7.52
7.08/7.11 7.24/7.45
7.16/7.3
Flavor strength ("just right" %)
53/92 ,
42/81 56/88
_ 56/83
Milky/dairy (lust right" %)
52/95
55/85 55/87
49/89
Saltiness ("just right" %)
64/93
54/71 68/84
68/79
Sourness ("just right" %)
62/95 .
66/92 -1 71/90
65/89 _
After taste ("moderate" %)
69/9
75/17 82/15
60/16
Pleasantness after taste (%)
77/86
86/47 86/71
77/86
Texture/Melting:
_ {
Overall texture liking (9 pt.)
7.09/7.58
7.23/6.98 7.19/7.43
7.14/7.41
Crumbliness liking (9 pt.)
7.22/7.59
7.17/7.05 7.36/7.55
7.25/7.34
Melting liking (9 pt.)
6.96/7.2
7.01/6.69 7.02/7.07
7.03/7.19
Cutting liking (9 pt.)
6.99/7.38 _
7.12/6.92 7.06/7.82
6.97/7.21
Firmness as Cutting ("just right" %)
31/86
24/74 7/79
28/83 _
Creaminess (just right" %)
49/90
33/80 43/81
42/84
Firmness (lust right" %)
52/86
38/78 39/89
41/85
Smoothness (lust right" %)
55/85
38/85 _ 50/83
47/87
Moistness liking (9 pt.)
60/90
48/83 49/82
50/86 .
Appearance:
1
Overall appearance liking (9 pt.)
7.1/7.67
7.22/7.36 7.39/7.55
7.38/7.54
Color (lust right" %)
69/95
70/95 , 60/96
62/92
Moist appearance (lust right" %)
59/94
55/80 50/83
59/94
The results are shown based on the scores from Los Angeles / Houston



[0036] The consumer evaluation results suggest
that the cheese of Example 3 was


at parity to the control (traditionally made base cheese without any
inhibitors). The


cheese of Example 3 did not significantly change the overall quality profiles
of the


cheese, nor impact consumer acceptance of the cheese. Further, the cheese of


Example 3 provided superior ratings over the cheeses of Examples 2 and 4.



Example 8: Alternative Combinations Reviewed


[0037] Alternative combinations were prepared and
reviewed for organoleptic


qualities and bacterial growth, in particular Listeria, Salmonella and E.coli.
Each


combination was tested under two different temperature conditions: 45 F and 55
F.


Although some of the alternative combinations tested did inhibit bacterial
growth over a


long period of time after package opening, the organoleptic qualities of the
combinations


along with the bacterial resistance was unacceptable. In assessing the
bacterial


growth, the presence of a bacterium of 1 log CFU was considered a failed test.



15

CA 02684721 2009-11-05



Table 14: Combination of Nisaplin, Sorbic Acid, Sea-i and Pediocin at 45 F
Interval (Day) Listeria Salmonella E.Coli
0 * * *
1 Pass Pass Pass
3 Pass Pass Pass
Pass Pass Pass
7 Pass Pass , Pass
Pass Pass Pass
14 Pass Pass Fail
21 Pass Pass Fail
24 Pass Pass *
28 Pass Pass *

35 Pass Pass *
42 Pass Pass *
49 Pass , Pass *
56 Pass Pass *
70 Pass Pass *
84 _ Pass Pass *
98 Pass Pass *

* Indicates not tested.



Table 15: Combination of Nisaplin, Sorbic Acid, Sea-i and Pediocin at 55 F
Interval (Day) Listeria , Salmonella E.Coli .
0 * * *

1 Pass Pass Pass
3 Pass _ Pass Pass
5 _ Pass _ Pass Pass
7 Pass Pass Fail
10 Pass Fail Fail
14 Pass Fail *
21 Pass * *

24 Fail * *
28 Fail _ * *
-



16

CA 02684721 2009-11-05



35 Fail *
*

* Indicates not tested.



Table 16: Combination of Nisaplin, Sorbic Acid, Sea-i and a Low Acid, Nisin
Producing Culture at 45 F
Interval (Day) Listeria Salmonella
E.Coli
_
0 * *
*
1 Pass Pass
Pass

3 Pass Pass _
Pass
Pass Pass Pass

7 Pass Pass
Pass

Pass Pass Pass

14 Pass Pass
Pass

21 Pass Pass
Pass

24 Pass Pass
Pass
28 , Pass Pass
Pass

35 Pass Pass
Pass

42 Pass Pass
Pass

49 Pass Pass
Pass

56 Pass Pass
Pass

70 Pass Pass
Pass

84 Pass Pass
Pass

98 Pass Pass
Pass

* Indicates not tested.



Table 17: Combination of Nisaplin, Sorbic Acid, Sea-le and a Low Acid, Nisin
Producing Culture at 55 F
Interval (Day) Listeria Salmonella
E.Coli

0 *
*

1 Pass Pass
Pass

3 Pass Pass
Pass

5 Pass Pass
Pass
_
7 Pass Pass
Pass

10 Pass Pass
Pass
_
14 Pass Pass
Pass

21 Pass Pass
Pass



17

CA 02684721 2009-11-05



24 Pass Pass Pass
28 Pass Pass Pass
35 Pass Pass Pass
42 Pass Pass Pass
49 Pass Pass Pass
56 Pass Pass Pass
70 Pass Pass Pass
84 Pass Pass Pass
98 Pass Pass Pass
* Indicates not tested.

Table 18: Combination of Nisaplin, Sorbic Acid, Sea-i and AM1079 at 45 F
Interval (Day) Listeria Salmonella E.Coli
0
1 Pass Pass Pass
3 Pass Pass Pass
Pass Pass Pass
7 Pass Pass Pass
Pass Pass Pass
14 Pass Pass Pass
21 Pass Pass Pass
24 Pass Pass Pass
28 Pass Pass Pass
35 Pass Pass Pass
42 Pass Pass Pass
49 Pass Pass Pass
56 Pass Pass Pass
70 Pass Pass Pass
84 Pass Pass Pass
98 Pass Pass Pass
* Indicates not tested.

Table 19: Combination of Nisaplin, Sorbic Acid, Sea-i and AM1079 at 55 F
interval (Day) Listeria Salmonella E.Coli

18

CA 02684721 2012-07-27



0 * * *
1 Pass Pass Pass -

3 Pass Pass Pass

Pass Pass Pass

7 Pass Pass _ Pass
Pass Pass Pass

14 Pass Pass Pass
_
21 Pass Pass Pass

24 Pass Pass Pass

28 Pass Pass Pass
35 Pass Pass Pass -
_
42 Pass Pass Pass
49 Pass Pass Pass -

56 Pass Pass Pass

70 Pass Pass Pass

84 Pass Pass _ Pass
98 Pass Pass Pass
_
* Indicates not tested.



[0038] All percentages throughout this specification are by weight percent
unless

otherwise specified.



19

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Administrative Status

Title Date
Forecasted Issue Date 2013-05-28
(22) Filed 2009-11-05
Examination Requested 2010-01-15
(41) Open to Public Inspection 2010-05-14
(45) Issued 2013-05-28

Abandonment History

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Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Application Fee $400.00 2009-11-05
Request for Examination $800.00 2010-01-15
Maintenance Fee - Application - New Act 2 2011-11-07 $100.00 2011-10-20
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Registration of a document - section 124 $100.00 2012-12-14
Final Fee $300.00 2013-03-15
Maintenance Fee - Patent - New Act 4 2013-11-05 $100.00 2013-10-17
Maintenance Fee - Patent - New Act 5 2014-11-05 $200.00 2014-11-03
Maintenance Fee - Patent - New Act 6 2015-11-05 $200.00 2015-11-02
Maintenance Fee - Patent - New Act 7 2016-11-07 $200.00 2016-10-31
Maintenance Fee - Patent - New Act 8 2017-11-06 $200.00 2017-10-30
Maintenance Fee - Patent - New Act 9 2018-11-05 $200.00 2018-10-29
Maintenance Fee - Patent - New Act 10 2019-11-05 $250.00 2019-10-25
Maintenance Fee - Patent - New Act 11 2020-11-05 $250.00 2020-10-30
Maintenance Fee - Patent - New Act 12 2021-11-05 $255.00 2021-10-29
Maintenance Fee - Patent - New Act 13 2022-11-07 $254.49 2022-10-28
Maintenance Fee - Patent - New Act 14 2023-11-06 $263.14 2023-10-27
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
KRAFT FOODS GROUP BRANDS LLC
Past Owners on Record
KOERTNER, MARY REGINA
KRAFT FOODS GLOBAL BRANDS LLC
LEWANDOWSKI, VICKIE JANE
MEHNERT, DAVID WEBB
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Abstract 2009-11-05 1 9
Description 2009-11-05 19 883
Claims 2009-11-05 3 116
Cover Page 2010-05-03 1 26
Description 2012-07-27 19 882
Cover Page 2013-05-09 1 26
Assignment 2009-11-05 2 104
Correspondence 2009-12-02 1 18
Correspondence 2010-01-13 1 50
Prosecution-Amendment 2010-01-15 1 47
Fees 2011-10-20 1 54
Fees 2012-10-18 1 55
Prosecution-Amendment 2012-01-30 3 118
Assignment 2012-12-14 16 963
Correspondence 2013-03-15 1 56
Prosecution-Amendment 2012-07-27 6 220