Note: Descriptions are shown in the official language in which they were submitted.
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~tICROORG.~\IS~.i REDUCTION yiETHODS AND CO~-iPOSITIONS
FOR FOOD
S
TECHNICAL FIELD
The present invention relates to methods for reduction in microorganisms,
especially for the purpose of making food, more especially produce, safe for
human
i 0 consumption, and to compositions, especially in concentrated, or the
corresponding
diluted liquid form, which are especially suitable for practicing said
methods.
BACKGROUND OF THE INVENTION
Fruits and vegetables, food preparation surfaces, and sometimes other food
products such as meats, are desirably washed prior to ingestion in order to
remove soils
15 and other unwanted residues which may be undesirably clinging to the
surfaces thereof. It
is also desirable to reduce microorganisms, thus ensuring safety.
It is especially desirable to provide effective, toxicologically-acceptable
compositions for food, including fruits and vegetables and/or meats that can
be sold in
concentrated form and used to create dilute low-sudsing liquid solutions which
can be
20 used to effect antimicrobial action and which desirably provide palatable
food without
removal. Dilute liquid solutions are convenient for the user, since they can
be applied
directly to soiled fruits and vegetables, or by simple immersion, thus
ensuring that all
parts of the food are treated. Clarity of the dilute liquids connotes
cleanliness to the user
and is thus highly desirable. Low sudsing is an important attribute so that
the elimination
25 of any suds is achieved quickly and easily. It is also of advantage if such
concentrates can
be diluted by the consumer using water that is not safe for use, since that is
sometimes the
only water that is available.
SUMMARY OF THE INVENTION
The present invention encompasses compositions and methods for treating food,
30 including produce, especially fruits and vegetables, (and compositions, as
disclosed
CA 02349288 2003-12-04
2
hereinafter, for practicing said methods) at a basic pH, even without rinsing,
to effect
microorganism reduction in a short time period, especially while maintaining
palatability.
Ill 1tS broadest aspect, it comprises a method for treating food to reduce the
level of
microorganisms, said treatment occurring just prior to consumption, comprising
the step of
contacting the surface of said food with an aqueous treatment composition
comprising:
anionic and/or nonionic detergent surfactant at a level of at least about
0.015%; basic
buffer to provide a pH of greater than about 8.5; and an electrolyte
concentration providing
at least about U.04 molarity of canons, for a period of time up to about one
minute, the
composition preferably being essentially free of any material that adversely
affects
palatability so that said food does not need to be rinsed before consumption.
In one embodiment there is provided a method for treating food to clean and
reduce
the level of microorganisms on the surface of said food, said method
comprising treatment
occurring just prior to consumption, comprising the step of contacting the
surface of said
food with a aqueous dilute treatment composition comprising toxicologically-
acceptable
I 5 anionic and/or nonionic detergent surfactant; total electrolyte to provide
at least about 0.04
molarity of canons; and toxicologically-acceptable basic buffer to provide a
pH of greater
than about 8.5; the composition being essentially free of any material that
adversely affects
safety or palatability, so that said food is not rinsed before consumption,
said composition
comprising: (a) greater than about 0.015% by weight of a member selected from
the group
consisting of sodium or potassium lauryl sulfate, potassium C8-14 soaps, and
mixtures
thereof; (b) toxicologically-acceptable basic buffer selected from the group
consisting of
water soluble borates, hydroxides, ortho-phosphates, carbonates, and/or
bicarbonates, to
provide a pl-i cof from about 8.5 to about 13 (c) sufficient electrolyte to
provide at least
about 0.04 molarity of canons without considering any surfactant canons: (d)
optionally,
from about 0.0005% to about 3% by weight of calcium ion sequestrant selected
from the
group consisting of water soluble salts of polyphosphates, organic
polycarboxylic acid, and
mixtures thereof; (e) optionally, toxicologically-acceptable preservative; (f)
optionally,
toxicologically acceptable suds suppressor; (g) the balance comprising an
aqueous carrier
containing from 3.5% to 10%, by weight, of ethanol.
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2a
The present invention comprises several more specific aspects including:
I. A method for making food, including produce and/or meat, safe to eat
comprising
contacting the surfaces of said food, shortly before ingestion so as to
minimize the chances
for recontamination, by direct application of a dilute aqueous treatment
composition
having a pH above about 8.5, typically comprising:
(a) at least about 0.015%, preferably less than about 5%, more preferably less
than
about 2%, and even more preferably less than about 1%, by weight of anionic
and/or nonionic detergent surfactant, preferably C6_,g alkyl sulfate,
sulfonate,
and/or soap, more preferably about C,~ alkyl, and preferably sufficient to
reduce the surface tension and to maintain the viscosity to less than about 50
cp., preferably to less than about 10 cp., and more preferably to less than
about
5 cp., to help maximize surface wetting and/or drainage thus minimizing
residue, bul preferably less than an amount that will affect palatability, of
toxicologically-acceptable detergent surfactant;
(b) toxicologically-acceptable basic buffer, preferably water soluble borates,
hydroxides, ortho-phosphates, carbonates, and/or bicarbonates, to provide a pH
of from about 8.5 to about 13, preferably from about 10 to about 12.5, more
preferably from about 10.5 to about 12.3, but preferably with low reserve
alkalinity ("reserve alkalinity" as used herein is equal to the percent of HC1
equivalent needed to lower the pH of the dilute treatment composition to 9.5),
that is typically less than about 10, preferably less than about 7, and even
more
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3
preferably less than about 4, so as to maximize safety, and the level of ortho-
phosphate, when present, being from about 0.01°ro to about 3%,
preferably
from about 0.05% to about 1%, more preferably from about 0.1% to about
0.5% of ortho-phosphoric acid equivalent;
S (c) sufficient electrolyte to provide at least about 0.04 molarity of
cations,
preferably at least about 0.08, and more preferably at least about 0.12;
(d) optionally, from about 0.0005% to about 3%, preferably from about 0.001%
to
about 1%, and more preferably from about 0.003% to about 0.5%, by weight
of calcium ion sequestrant, preferably polyphosphate detergent builder such as
the sodium salt of tripolyphosphate (referred to hereinafter as "STPP") or, a
salt of an organic polycarboxylic acid, such as the sodium salt of
ethylenediaminetetraacetic acid (referred to hereinafter as "EDTA".) and/or a
salt of citric acid to sequester calcium in hard water to control calcium
precipitates;
(e} optionally, toxicologically-acceptable preservative;
(f) optionally, toxicologically-acceptable suds suppresser; and
(g) the balance comprising an aqueous carrier selected from water and,
optionally,
low levels of low molecular weight, toxicologically-acceptable organic solvent
such as ethanol, glycerol, etc. and/or minor ingredients;
all of the acidic materials above being, of course, neutralized under the
alkaline conditions
of the product, and said composition being essentially free of any material
that is not
toxicologically acceptable, said treatment being able to effect at least a one
log reduction
- of E-coli in less than about 1 minute, optionally followed by draining
and/or drying, even
without rinsing, said food being then ready for consumption and having
desirable
palatability. For the purposes of this invention any anionic surfactant and
its counter ion
are not included in the determination of the salt level.
The inventions disclosed herein encompass concentrated compositions suitable
for
use in preparing such dilute compositions for treating food at a basic pH
above about 8.5,
by diluting with water using from about 0.1% to about 5%, preferably from
about 0.5% to
about 2%, of the concentrated composition, by weight of the dilute
composition, said
concentrated composition comprising:
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(a) from about 0.1 % to about SO°io, preferably from about
0.5°ro to about 20%, and
more preferably from about 1% to about 10%, by weight of toxicologically-
acceptable anionic and,-'or nonionic detergent surfactant, preferably base-
stable
anionic surfactant, and more preferably, a C6_i~ alkyl sulfate ancL'or Cg_14
S soap;
(b) toxicologically-acceptable basic buffer, preferably potassium and/or
sodium
and/or calcium hydroxide, orthophosphate, carbonate, and/or bicarbonate, to
provide a pH of from about 8.5 to about 13, preferably from about 10 to about
. 12.5, more preferably from about 10.5 to about 12.3, in said dilute
composition, but with low reserve alkalinity in said dilute composition,
preferably less than about I0, more preferably less than about 7 and even more
preferably less than about 4, to avoid damage to a human, the level of
orthophosphate, when present, being from about 3% to about 60%, preferably
from about 5% to about 60%, more preferably from about 10% to about 55%,
by weight of ortho-phosphoric acid equivalent;
(c) suffcient electrolyte to provide at least about 0.04 molarity of cations
once
diluted for use, preferably at least about 0.08, and more preferably at least
about 0.12;
(d) optionally, from about 0.1 to about 35%, preferably from about 1 to about
25%, more preferably from about 2 to about 20%, of toxicologically-
acceptable calcium ion sequestrant, preferably polyphosphate or organic
polycarboxylate, more preferably STPP or EDTA, or combinations of the two,
to control calcium ions;
(d) optionally, toxicologically-acceptable preservative;
(e) optionally, toxicologically-acceptable suds suppresser; and
(fj the balance comprising compatible, toxicologically-acceptable inert and/or
minor ingredients.
In all of the above lists of components, if an ingredient can be classified in
more
than one place, it will be classified in the first place it can appear.
Preferably all
ingredients are food grade, since they may be ingested.
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S
A more specific method for preparing food, especially produce such as fruits
and
vegetables involves exposing the food to a dilute aqueous solution having a
basic pH of
more than about 8.~ as described above, for a period of time of up to about
one minute,
said aqueous cleaning solution comprising potassium cations andlor sodium
canons.
These cations are desirable in the diet for many reasons. Therefore, their
presence in a
composition for use in treating food materials like vegetables and fruits
without rinsing is
desirable. Also, the potassium canon is more useful than the sodium cation for
soaps,
since the potassium soaps are quite soluble as compared to the sodium soaps,
especially at
low temperatures.
An alkaline method for treating food can comprise contacting the surfaces of
produce with an aqueous solution prepared by creating a solution having a pH
of from
about 8.5 to about 13, preferably from about 10 to about 12.5, more preferably
from about
10.5 to about 12.3, using the concentrated composition above and impure water,
to
provide pure solutions that kill microorganisms on the surface of food. It is
important to
reduce the level of microorganisms on the surface of food.
Another preferred variation in the above methods for treating food such as
produce involves placing concentrated compositions, as disclosed herein, into
containers
in association with instructions to use the composition to form said dilute
solutions to
treat food. Such instructions are very important, since the amount of
dilution, the time of
treatment, special instructions regarding rinsing , and the ability to use
impure water to
form the treatment solution are not intuitive. It is also important that the
instructions be
as simple and clear as possible, so that using pictures and/or icons is
desirable.
The balance of the composition can comprise various optional adjunct
materials,
pH-adjusting~gents, perfumes or essences, preservatives, suds suppressors, and
the like.
The ingredients in the above concentrated compositions are preferably "food
grade" and selected and used in proportions which provide substantially clear
dilute
compositions. "Substantially clear" includes only minimal haziness, and
preferably the
compositions are completely clear. The ingredients are also selected to have
minimal
odor, both initially and after storage. The lack of objectionable odor is
especially
important in compositions for use on food.
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6
In order to mask any objectionable odor, the compositions can contain a food
grade
or GRAS (defined hereinafter) perfume, or essence, ingredient. Especially
preferred for
this use are oils derived from citrus fruit, e.g., oranges, lemons, limes,
grapefruits,
tangerines, tangelos, etc. which contain relatively large amounts of terpenes.
Preferred compositions for use herein contain only materials that are food
grade or
GRAS, including, of course, direct food additives affirmed as GRAS, to protect
against
possible misuse by the consumer. Traditionally, most suggestions for cleaning
of fruits
and/or vegetables have contemplated a commercial scale where there is
typically more
control over the conditions, especially the amount and thoroughness of
rinsing. The
present invention includes use by individual consumers without rinsing, so
that it is
essential that extra safety be built into the product. Failure to rinse
thoroughly after
cleaning is less of a concern if all of the ingredients are GRAS and/or food
grade.
The use and selection of cleaning ingredients for the purpose of washing
fruits and
vegetables is described by the United States Code of Federal Regulations,
Title 21,
Section 173.315: "Ingredients for use in washing or lye peeling of fruits and
vegetables".
These regulations restrict the ingredients that may be used for direct contact
with food to
those described as "generally recognized as safe" (GRAS}, and a few other
selected
ingredients. These sections also provide certain limitations on the amount of
material that
can be used in a given context. However, there are no regulations, or
suggestions, for
methods of making food safe for consumption using aqueous compositions that do
not
need to be removed. Also, there is no known method for killing microbes using
materials
like hypochlorite, iodine, etc. at low levels that provide desirable
palatability.
DETAILED DESCRIPTION OF THE INVENTION
The following toxicologically-acceptable ingredients are used in the
preparation of
the preferred compositions herein. By "toxicologically-acceptable" is meant
that any
residues from the ingredients of the compositions which may remain on the
fruits or
vegetables cleansed therewith are safe for ingestion by humans and/or lower
animals.
Detergent Surfactant
Synthetic Anionic Surfactant - Base stable anionic surfactants can be
employed,
e.g., as allowed in the United States by the United States Code of Federal
Regulations
CA 02349288 2003-12-04
7
(CFR), Title 21, Section 173.315. Specific mention is made of salts of
dodecylbenzene
sulfonate, typically at levels up to 0.2°~0. Also described in the CFR
are phosphate esters
of ethylene ancfor ethylene/propylene oxide adducts of aliphatic alcohols,
dioctyl
sulfosuccinate, and 2-ethylhexyl sulfate.
The anionic surfactant is preferably selected from materials known in the art,
such
as C6_Ig alkyl sulfates and/or sulfonates; C6_IS alkylbenzene sulfonates; di-
C6_10 alkyl
sulfosuccinates, etc. The alkyl sulfates are preferred, for antimicrobial
effectiveness and
palatability, especially as the sodium salts. Potassium Cg_ 14 soaps are also
preferred.
Mixtures of such alkyl sulfates and soaps are also preferred.
Nonionic Surfactant - Nonionic surfactants, when used, are preferably selected
from materials known in the art, such as alkylene oxide (ethylene oxide and/or
propylene
oxide) adducts of C10-18 aliphatic alcohols or acids, polysorbates, C10-18
aliphatic
alcohol adducts of glucose (alkyl polyglucosides). The specific nonionic
surfactant
selected ideally has a hydrophilic-lipophilic balance (HLB) greater than about
10, and a
cloud point above about 35°C in the composition. The United States Code
of Federal
Regulations (CFR) specifically describes an ethylene oxide/propylene oxide
adduct of
C12-18 aliphatic alcohol of molecular weight of about 800. Such a material is
available
~rM
as PLURAFAC RA-20 (BASF).
In compositions containing soap, the alkoxylated alcohol functions mainly as a
dispersant for any soap curd which may form during the cleansing operation.
Further, it is
recognized that the selection of non-nitrogen containing nonionics can
minimize the
possibility of microbial growth in the dilute surfactant compositions.
Fatt~Salts - The compositions herein can contain soap, especially a Cg_14 soap
like coconut fatty acid middle cut soap. Lauric acid is convenient for this
use. Specific
solubilizing surfactants in higher proportions can be used to solubilize these
soaps.
However, soaps should not be used in large quantities because of taste
considerations.
The presence of the detergent surfactant is important for microorganism
reduction,
especially at a pH of less than about 10. The detergent surfactant also is
used for
reduction of the surface tension and controlling viscosity. It is highly
desirable that the
dilute treatment compositions have a low viscosity, typically less than about
50,
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preferably less than about 10, and more preferably less than about ~. The low
viscosity
improves the completeness of the treatment by promoting spreading over the
surface of
the food, especially where there are layers, rugosities, etc. The low
viscosity also
improves drainage, thus providing at least some soil removal. Low viscosity
also
improves speed of drying, if that is desired. Thus, the detergent surfactant
provides highly
important advantages in terms of treatment.
In combination with salt, the detergent surfactant improves antimicrobial
action.
The presence of the surfactant, and especially the alkyl sulfate, provides
improved kill
and/or rate of kill, especially for short times and/or lower pH.
It is important that the detergent surfactant not affect palatability.
Accordingly,
the level should be low. As discussed before, soap is not usually used in
large amounts
because of taste considerations and food grade surfactants are highly
desirable for taste
considerations.
Alkaline Buffer
Toxicologically-acceptable basic buffers are used in the compositions herein
to
maintain product pH in the desired range. For ease of formulatability, it is
often desirable
that such basic buffers be in their potassium salt form, especially in liquid
concentrates
that utilize neutralized fatty acid surfactants. Sodium salts are acceptable,
and even
preferred, in solid, e.g., powder formulas or in conjunction with alkyl
sulfate/sulfonate
surfactants. Potassium/sodium carbonate and/or potassium/sodium ortho-
phosphate are
convenient and preferred basic pH buffers. Calcium and/or magnesium hydroxides
can
also be used to create a basic pH, especially if the composition does not
contain calcium
ion sequestrant. Sodium and potassium hydroxides can be used as part of
alkaline buffer
systems. TI~e levels and identities of the ingredients are adjusted to provide
dilute
products having the desired viscosities as set forth herein, e.g., less than
about 50,
preferably less than about 10, more preferably less than about 5 centipoise
under shear of
> ~ 1000 sec' 1.
The pH is preferably not greater than about 13, and especially does not
contain
large amounts of buffer at higher pHs for consumer safety, especially when the
compositions are not fully removed. Reserve alkalinity should be from about 0.
I to about
10, preferably from about 0.2 to about 7, and more preferably from about 0.3
to about 4.
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The pH buffer is also part of the electrolyte, discussed hereinafter.
Electrolyte
In combination with the surfactant, a sufficiently high electrolyte
concentration is
essential for effective microorganism reduction in short times and/or at a low
pH.
Suitable electrolytes include: calcium disodium ethylenediaminetetraacetate
(EDTA),
disodium EDTA, potassium nitrate, sodium nitrate, sodium nitrite, stannous
chloride,
aluminum nicotinate, calcium pantothenate, calcium chloride double salt,
potassium
iodide, zinc methionine sulfate, calcium silicate, iron ammonium citrate,
disodium
guanylate, disodium inosinate, salts of carrageenan, salts of furcelleran,
calcium
lignosulfonate, calcium lactobionate, gibberellic acid and its potassium salt,
potassium
bromate, dioctyl sodium sulfosuccinate, sodium acid pyrophosphate, aluminum
sulfate,
aluminum ammonium sulfate, aluminum potassium sulfate, aluminum sodium
sulfate,
calcium phosphate, sodium carboxymethylcellulose, sodium caseinate, sodium
phosphate,
sodium aluminum phosphate, sodium tripolyphosphate, aluminum calcium silicate,
.i calcium silicate, magnesium silicate, sodium aluminosilicate, sodium
calcium
aluminosilicate, hydrated tricalcium silicate, calcium ascorbate, calcium
sorbate,
potassium bisulfate, potassium metabisulfite, potassium sorbate, sodium
ascorbate,
sodium bisulfate, sodium metabisulfite, sodium sorbate, sodium sulfite, sodium
acid
phosphate, calcium diacetate, calcium hexametaphosphate, monobasic calcium
phosphate,
dipotassium phosphate, disodium phosphate, sodium hexametaphosphate, sodium
metaphosphate, sodium phosphate, sodium pyrophosphate, tetra sodium
pyrophosphate,
sodium tripolyphosphate, calcium phosphate, calcium pyrophosphate, sodium
phosphate,
zinc chloride, zinc gluconate, zinc oxide, zinc stearate, zinc sulfate,
potassium acid
tartrate, ammonium bicarbonate, ammonium carbonate, ammonium chloride,
ammonium
2~ hydroxide, ammonium citrate, dibasic ammonium phosphate, monobasic ammonium
phosphate, dibasic ammonium sulfate, calcium acetate, calcium alginate,
calcium
carbonate, calcium chloride, calcium citrate, calcium gluconate, calcium
glycerophosphate, calcium hydroxide, calcium iodate, calcium lactate, calcium
oxide,
calcium pantothenate, calcium propionate, calcium stearate, calcium sulfate,
copper
gluconate, copper sulfate, fernc ammonium citrate, ferric chloride, ferric
citrate, ferric
phosphate, ferric pyrophosphate, ferric sulfate, ferrous ascorbate, ferrous
carbonate,
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ferrous citrate, ferrous fumarate, ferrous gluconate, ferrous lactate, ferrous
sulfate, iron,
elemental, magnesium carbonate, magnesium chloride, magnesium citrate dibasic
,
magnesium hydroxide, magnesium oxide, magnesium phosphate, magnesium sulfate,
manganese chloride, manganese citrate, manganese gluconate, manganese sulfate,
monosodium phosphate derivatives of mono- and diglycerides, nickel, potassium
alginate,
potassium bicarbonate, potassium carbonate, potassium chloride, potassium
citrate,
potassium hydroxide, potassium iodide, potassium iodate, potassium lactate,
potassium
sulfate, sodium acetate, sodium alginate, sodium benzoate, sodium bicarbonate,
sodium
carbonate, sodium chloride, sodium citrate, sodium diacetate, sodium
hydroxide, sodium
10 hypophosphite, sodium lactate, sodium metasilicate, sodium propionate,
sodium
sesquicarbonate, sodium tartrate, sodium potassium tartrate, sodium
thiosulfate, stannous
chloride (anhydrous and dihydrated).
It will be recognized that the above electrolyte salts should preferably be
used in
w,ounts that are non-toxic and which do not cause unacceptable taste and/or
feel in the
mouth when the salts are not removed. The molarity of cations is preferably at
least 0.04,
more preferably at least about 0.08, and even more preferably at least about
0.12.
SeQuestrant/Builder
The preferred sequestrant and/or builder herein is polyphosphate salt or
organic
polycarboxylic salt, e.g., sodium and/or potassium citrate, and/or sodium
and/or
potassium ethylenediaminetetraacetate, which are standard items of commerce
and are
GRAS. Other organic polycarboxylic acids, especially those that are GRAS, such
as
citric, tartaric, malic, etc. acids, can also be used. A preferred version of
polyphosphate is
an anhydrous Fast Dissolving STPP manufactured by the FMC corporation. Complex
phosphates can also be used, and are highly useful to maintain the clarity of
dilute
solutions made from hard water, but are generally avoided due to regulatory
considerations where phosphate levels are specifically forbidden or highly
restricted.
Typically, the sequestrant/builder is present at a level of from about 0.0005%
to about
3%, preferably from about 0.001% to about 0.5%, and more preferably from about
0.003% to about 0.2%, by weight of the dilute composition.
Sequestrant/builders can
maintain the efficacy of the formulas in the presence of hardness.
Sequestrant/builders
CA 02349288 2003-12-04
are a special case of the electrolyte and are considered in the computation of
the
electrolyte molarity.
Preservative
Formulating the present concentrated compositions with essential surfactant
and
electrolyte reduces the tendency for biological growth of contaminants, such
as bacteria,
fungi, or molds. However, preservatives can help insure the lack of biological
growth
through contamination in making or in use. Standard food-grade preservatives
such as
ethylenediaminetetraacetic acid and/or the salts thereof, at a level of from
about 0.001%
to about 0.2% of ethylenediaminetetraacetic acid, or its sodium and/or
potassium salts,
can be used although, in general, the compositions herein do not require a
preservative.
Fluid Carrier
The major proportion, e.g., more than about two thirds, (typically,
approximately
80%-99.7%, by weight) of the dilute compositions herein comprises water as the
fluid carrier for the ingredients. As noted in the Examples hereinafter, water-
ethanol can also be employed and is especially preferred when formulating the
basic pH
compositions herein. The ethanol level in the dilute composition preferably
should not
exceed 10% in the solution used to treat the produce, to avoid an alcoholic
odor. Other
compatible, water-soluble, low molecular weight solvents such as glycerol can
also be
used. Glycerol can also be used in solid compositions to minimize fines. It is
an
advantage of this invention, that one can use impure water to prepare the
dilute
composition, the microorganisms being killed by the high pH and/or surfactant
and/or
builder and/or electrolyte. As used herein, "impure water" is water that is
impure by
reason of microorganisms being present.
Optional Ingredients
Polyethylene Glycol - The water-soluble polyethylene glycol polymer (PEG)
employed which can be employed herein is the known article of commerce and is
available under a variety of trade marks, of which CARBOWAX (Union Carbide
Corporation) is exemplary. PEG's in the average molecular weight range of from
about
200 to about 20,000 can be used herein, and PEG as CARBOWAX in the average
molecular weight range of at least about 200, typically 300 to about 9500, is
convenient
and preferred. The dilute compositions herein can comprise at least about
0.001 %, by
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weight, of the PEG and will typically comprise from about 0.005% to about 0.1
%, by
weight, of PEG. The amounts used can vary with the molecular weight of the
PEG, the
amount of surfactant used in the composition, the desired viscosity of the
composition,
and like factors within the discretion of the formulator. In a typical mode,
the prefenred
compositions herein that have an improved tactile impression will comprise
surfactant/PEG weight ratios in the range from about 1:2 to about 30:I,
preferably from
about I:1 to about 15:1.
The compositions herein which contain the polyethylene glycol are
characterized
not only by their excellent cleaning performance and sudsing/rinsability
properties, but
also by their improved "feel". The improved feel of the compositions which
come into
contact with the users' hands is a qualitative tactile impression. However,
this improved,
"non-slippery", "non-soapy" improvement in skin feel can be demonstrated by
rubbing
Test (PEG-containing) and Control (no PEG) compositions on the hands or inner
forearms
of volunteer graders. Even in such rudimentary tests, the graders can readily
distinguish
the improved tactile impression of the compositions.
Antioxidants The use of surfactants, and especially soaps, can be complicated
by
development of off odors and/or yellowing of the compositions in which they
appear.
These undesirable properties are believed to be caused by complex side
reactions initiated
by the reaction of oxygen with primarily the polyunsaturated components of the
fatty acid
stock. These results can be avoided, or minimized, by avoiding contact with
air, or by
controlling the quality of the fatty acid stock so that the amount and type of
polyunsaturates are minimized as described above, and/or by the addition of
chelants
and/or antioxidants.
It has been found, that the addition of tocopherols (e.g., Vitamin E, or
tocopherol
acetates) in alkaline fonmulations is advantageous, as they do not degrade,
nor do they
impart a strong color. They inhibit the development of off odors for extended
periods of
time so that the need for masking scents is minimized, or eliminated,
particularly for oleic
acid stocks of high quality, as described above. The use of butylated phenols,
such as
BHT and BHA is also useful, but their effectiveness appears more limited and
they can
impart stronger colors to the compositions. Other food grade antioxidants such
as
Vitamin C, sorbates, and sulfites, are desirable to prevent deterioration of
the
CA 02349288 2003-12-04
13
compositions by the action of oxygen, but care must be taken since vitamin C
can suffer
color degradation and sulfites can cause odor problems. Sulfites also have
been the target
of potential health concerns.
Suds suppressors. (Silicones and their derivatives) At low levels, suds
suppressors
or antifoamers can be used, especially in the case where a certain surfactant
level is
desired for wetting and/or efficacy, but the degree of foam generated in the
washing of
produce is desired to be kept low. The amount of suds suppresser can be
tailored in
yM TM
conjunction with the type and level of surfactant used. DC-4270 and DC2-4242
from
Dow Corning are useful suds suppressors.
The PEG, previously discussed, can alternately be used as a carrier or binder
material for a silicone suds suppresser particle in dry powder concentrate
formulas.
Typically the PEG molecular weights are such that the PEG is a solid at room
temperature
to contain the silicone. A preferred M.W. in this case is 8000.
In the case where PEG is an integral part of the carrier for silicone in a
power concentrate,
I S caution should be used in the processing of the material to avoid
excessive shearing of the
dry product. PEG can be soft enough that excessive shear could alter the
integrity of the
particle formed with it.
Mild fragrances. Odor ingredients can be useful at low levels in concentrates.
They can give a concentrate a favorable odor, but under dilution are not
noticeable in
solution or on treated items.
Conventional halogen antimicrobials. One of the advantages of the present
invention is that it makes it unnecessary to use hypochlorite, or iodine, as a
means of
reducing microorganism populations. Such materials are known to have
undesirable
tastes, and can add to environmental pollution. However, it is sometimes
desirable to
have a small amount of hypochlorite salt, typically lithium, sodium,
potassium, calcium,
and/or magnesium, and/or a source of iodine, present at a low level for
additional kill of
m~croorgamsms.
Usage
The concentrated compositions herein are preferably used by placing them in a
container, such as a pan, with water, preferably pure, to form the dilute
compositions and
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facilitate immersion of the food, or by dilution and then application to the
surface to be
treated.
A typical use involves treating individual items of food in a "bath" followed
by
draining the food and/or drying, to minimize the amount of composition left on
the food.
In an optional process for using the dilute compositions described herein, the
food
product is rinsed, cleaned, rubbed, and/or wiped off with a suitable clean
material like
cloth, sponge, a paper towel, etc. In another optional process, potentially
impure water is
treated with the concentrated composition to kill microorganisms and this
"treated" water
is used to rinse food that has been treated with the dilute treatment
composition in another
vessel. This protects against the undetected gradual contamination of the
original
treatment composition. The "rinse" composition can contain lower levels of the
concentrate, since all that is needed is to kill the microorganisms in the
water itself.
Surprisingly, the compositions and processes described herein can provide
effective disinfectancy/sanitization. In order to provide good kill of
microor~anisms_
especially bacteria, one should use high concentrations and/or longer exposure
times.
Typically, the dilute compositions should be used full strength and allowed to
remain on
the food for up to about one half minute, preferably up to about one minute.
Longer
exposure times (i.e., the time that the bacteria are in contact with the
product) are not
required to observe antimicrobial benefits.
Higher pHs are also better, in general.
The methods herein can comprise forming the dilute treatment composition using
either (a) pure and/or (b) impure water and after application by immersion
and/or spray,
then either (1) not rinsing so that any removal is by mechanical means,
absorption, and/or
draining; (2) rinsing with pure water if it is available; and/or (3) treating
impure water
with the dilute treatment composition to create "pure" rinse water and then
rinsing.
Food
All kinds of foods can be treated. Examples include: produce including fruits
and
vegetables such as apples, grapes, peaches, potatoes, lettuce, tomatoes,
celery, and the
like, that are to be eaten aRer treatment, and edible animal protein,
especially meat,
seafood and poultry, including foodstuffs which are comprised essentially of
the protein
found in such foods sources including, but not limited to, beef, pork,
chicken, turkey, fish,
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shellfish and game meats such as venison, rabbit and the like. Said edible
animal protein
includes the processed forms of said protein sources, including, but not
limited to, such
forms as around beef, ground turkey, bologna, hot dogs, sausages, fish cakes,
and the like.
The food is preferably ready to eat after treatment, and is eaten shortly
thereafter to
S minimize recontamination.
The compositions can also be used for cleaning (especially spot removal),
disinfectancy, or sanitization, on non-food (i.e., any surface which is not
used as food,
even those which are not in contact with food), inanimate, household surfaces,
especially
those used in food production and other food-contacting surfaces (surfaces
that come in
10 contact with food). E.g., cutting boards, counter tops, utensils, dishes,
colanders, sinks,
sponges, towels, dish cloths, cloth napkins (serviettes), table cloths, and
other surfaces
that come in contact with food. It is desirable to disinfect/sanitize before
the surfaces
come in contact with the food, and is desirable to redisinfect/sanitize
whenever the
surfaces become recontaminated. The products herein, containing all GRAS
and/or food
15 grade ingredients, are perfect for this purpose. On hard surfaces, of
course, the
compositions can be removed, after sufficient time has elapsed, by rinsing if
pure water is
available, or by absorption/wiping with an appropriate object, e.g., paper
towel, sponge,
squeegee, etc.
The compositions of this invention can also be used to treat/clean other non-
food
inanimate household surfaces, such as fabrics, e.g., clothing, shoes, and
shower curtains,
especially those that are used by infants, especially toys, diapers (napkins),
and bibs. The
contaminated fabrics can be disinfected/sanitized, then allowed to drain
and/or dry, while
minimizing the risk if the infant puts the fabric or other article in its
mouth. However, it
is desirable to rinse fabrics, at least with water that contains less
alkalinity. The fabric can
be treated totally, or by spot treatment, then the composition is preferably
removed, at
least partially, e.g., by draining, absorbency, and/or mechanical force. The
products can
also be used to treat animals and humans to disinfect skin, hair, etc. Care
should be used
to avoid damage if the product has a high pH.
Packaging the products herein in a container with instructions for usage in
terms
of timing and proper dilution in order to provide disinfectancy/sanitization,
will help the
individual consumer by providing information for proper usage in order to
remove/kill
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microorganisms. It is a special advantage of the product that it can be used
for this
purpose at a time in the food production process where recontamination is
minimized.
The instructions desirably provide assurance that short tirr~es are acceptable
and/or that
rinsing is not needed in order to avoid possible recontamination by rinsing
with impure
water.
For fabrics, the pH of the compositions is preferably below about 11.5, more
preferably below 1 I.O.
For fabric and hard surfaces, the distribution of the compositions of this
invention
can be achieved by using a spray device, a roller, a pad, etc., or dipping in
a "bath" of said
compositions. Spraying is a preferred method.
All parts, percentages, and ratios herein are"by weight" unless otherwise
stated.
All number values are approximate unless otherwise stated.
The following Examples illustrate the compositions and processes of this
invention, but are not intended to be limiting thereof. The exemplified basic
liquid dilute
IS treatment compositions can be prepared at pH 8.5-13 by dissolving the
concentrated
compositions, or the individual ingredients, in water or water-ethanol using
conventional
mixing apparatus. In a convenient mode, e.g., the concentrate of Example Q ,
water is
placed in a treatment vessel. Sodium lauryl sulfate, trisodium phosphate
crystals, and
sodium chloride are added in the named sequence, with stirring.
The following examples depict the bacteria kill efficacy of the proposed
invention
as determined by a standard AOAC germicidal and detergent sanitizing test.
Test
organisms E. coii, ATCC I 1229, or Staphylococcus aureus, ATCC 6538, are
prepared in
an inoculum with a 5% organic soil load (horse serum) prepared with French
culture
bottles to achieve higher cfu/ml. The test exposure temperature is 25°C
and incubation
time for survivor count is 48-54 hours at 35°C.
As used herein, total cation molarity does not include any cation from the
surfactant.
EXAMPLES
The following solutions (A-F) were prepared and tested for efficacy.
Examples where no surfactant, but above our specified salt level, are
insufficient.
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Comparative Comparative
Example A Example B
Nominal Wt % Nominal Wt o
NaHC03 2.0 NaHC03 2.0
NaOH 0.19 NaOH 0.19
Ethanol 2.0 Water balance
Water balance pH 10.5
pH 10.5
Total canon 0.289
molarity
Total cation molarity 0.289 Log reduction E-Coli 0.23 @ 1 minute
Log reduction E-Coli 0.29 @ 1 minute
Example where low surfactant and low salt is insufficient.
Comparative
Example C
Nominal Wt
Sodium Lauryl Sulfate 0.01
Na3P04~ 12Hz0 0.46
Water balance
pH 10.5
Total cationmolarity 0.036
Log reduction E-Coli 0.05 @ 1 minute
Example showing where Oleic acid (C,a) is not preferred.
Comparative
Example D
Nominal Wt
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Oleic acid 0.44
NaHCO, 2,0
KOH 1.81
Ethanol 2.0
Citric acid 0.52
PEG 3350 0.1
Water balance
pH 10.5
Total cation molarity 0.359
Log reduction E-Coli 0.47 @ 1 minute
Examples showing where low total salt cation molarity, even with preferred
surfactants, is
insufficient.
Comparative Example
E
Nominal Wt
Sodium Lauryl Sulfate0.2
Na3P0:~ 12H20 0.175
Na2C03 -
STPP 0.1
Water balance
pH 11.5
Total cation molarity 0.027
Log reduction E-Coli 0 @ 1 minute
Comparative Comparative
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Example F Example
G
Nominal Wt '_~ominal
% Wt
Sodium Lauryl 0.15 SodiumLauryl 0.1
Sulfate
Sulfate
Na,PO.~ 12Hz0 0.225 Na3P0.~ 12Hz0 0.275
STPP 0.1 STPP 0.1
Water balance Water balance
pH 11.5 pH --11.5
Total cation molarity0.031 Total cation molarity0.035
Log reduction 0 @ 1 minute Log reduction E-Coli0 @ 1 minute
E-Coli
Comparative Comparative
Example H Example
I
Nominal Wt Nominal
% Wt
Sodium Lauryl 0.05 SodiumLauryl 0.04
Sulfate
Sulfate
Na3P0,~ 12H20 0.325 Na3P04 12HZ0 0.335
STPP 0.1 STPP 0.1
Water balance Water balance
pH 11.5 pH 11.5
Total cation 0.039 Total cation molarity0.04
molarity
Log reduction 0 @ 1 minute Log reduction E-Coli0 @ 1 minute
E-Coli
Examples A-R show a combination of specific surfactant at the required level,
and
specified total salt cation molarity, gives surprisingly successful results.
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A B
Nominal Wt Nominal
% Wt%
Sodium Lauryl 0.063 SodiumLauryl Sulfate0.5
Sulfate
NazPO.~ 12H20 0.176 NaOH 0.05
NaZC03 0.25 NaHCOz 2.0
STPP - Water balance
Water balance pH g.5
pH 11.5
Total cation molarity0.062 Total cation molarity0.253
Log reduction 1.5 @ 1 minuteLog reduction E-Coli4.5 @. 1
E-Coli minute
C D
Nominal Wt Nominal Wt
%
Sodium Lauryl 0.05 SodiumLauryl 0.5
Sulfate
Sulfate
NaOH 0.8 NaOH 0.1
NaHC03 2.0 NaHC03 0.25
NazS04 - NaZS04 3.0
Water balance Water balance
pH 10.5 pH 10.5
Total cation molarity0.442 Total cation 0.482
molarity
Log reduction 1.7 @ 0.5 minuteLog reduction E-Coli1.5 @ 0.5
E-Coli minute
3.3 @ 1 minute 4 @ 1 minute
5
E F
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Nominal Wt ,% Nominal Wt
~o
Lauric Acid 1.87 SodiumLauryl 0.11
Sulfate
KOH 2.25 NaOH 1.25
KHC03 2.38 NaHC03 2.0
Ethanol 2.0 Ethanol 3.5
Na2EDTA 0.003 Na~EDTA 0.003
Citric Acid 0.52 Citric Acid 0.52
PEG 3350 0.50 Water balance
Water balance
pH 11.5 pH 10.8
Total cation 0.551 Total cation 0.557
molarity
molarity
Log reduction 3.1 @ 0.5 minuteLog reduction 6.7 @ 0.5 minute
Staph. Staph.
Aureus Aureus
3.4 @ 1 minute 6.9 @ I minute
G H
Nominal Wt % Nominal Wt
Lauric Acid I.87 SodiumLauryl 0.5
Sulfate
KOH 2.26 NaOH 0.62
NaHC03 2.0 NaHC03 0.55
Ethanol 7.5 Ethanol 2.0
Na2EDTA 0.003 Na2EDTA 0.003
Citric Acid 0.52 Na Acetate 0.10
PEG 3350 0.50 Citric Acid 0.54
Water balance PEG 200 0.10
pH 11.5 Water balance
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pH 11.57
Total cation molarity 0.552 Total cation 0.223
molarity
Log reduction Staph. 2.7 @ 0.~ minute Log reduction Staph. 3.9 @ 0.~ minute
Aureus Aureus
3.4 @ 1 minute 4.1 @ 1 minute
I
Nominal Wt % Nominal Wt
Sodium Lauryl 0.02 SodiumLauryl 0.02
Sulfate
Sulfate
Na3POa 12HZ0 0.36 Na3P04 12H20 0.31
NazC03 0.05 NaZCO~ 0.15
STPP 0.05 STPP _
Water balance Water balance
pH ~ 11.5 pH ~ 11.5
Total cation molarity0.045 Total cation 0.054
molarity
Log reduction 5.2 @ 0.5 minuteLog reduction 1.1 @ 0.5
E-Coli E-Coli minute
7 @ 1 minute 3.1 @ 1 minute
K
Nominal Wt
Sodium Lauryl Sulfate 0.02
Na3P0~~ 12H20 0.26
NaZC03 0.2
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STPP
ii'ater balance
pH -1 I.S
Total cation molarity 0.059
Log reduction E-Coli 1 @. 0.~ minute
2.7 ~1 minute
L M
Nominal Wt % Nominal
Wt
Sodium Lauryl 0.125 SodiumLauryl 0.125
Sulfate
Sulfate
NazPOa 12H20 0.2 Na3POa 12H20 0. I 5
Na2C03 0.15 Na2C03 0.2
Water balance Water balance
pH 11.5 pH ~1I.5
Total cation 0.044 Totalcation molarity0.051
molarity
Log reduction 1.4 @ 0.5 minuteLog reduction 1 @ 0.5
E-Coli E-Coli minute
1.3 @ 1 minute 1.2 @ 1
minute
S
N O
Nominal Wt Nominal Wt
%
Sodium Lauryl 0.075 SodiumLauryl 0.1
Sulfate
Sulfate
Na~PO.~ 12Hz0 0.21 Na3P0.~ 12HZ0 0.28
Na2C03 0.3 Na2C03 0.4
Water balance Water balance
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pH 11.5 pH 11.5
Total cation molarity 0.074 Total cation 0.099
molarity
Log reduction E-Coli 3.2 @ 0.~ minute Log reduction E-Coli S @ 0.5 minute
3.8 @ 1 minute 3.7 @. 1 minute
P Q
Nominal Wt Nominal
% Wt
Sodium Lauryl 0.016 SodiumLauryl 0.125
Sulfate
Sulfate
Na3P0:~ 12Hz0 0.285 Na3P04 12H20 0.33
NaCI 0.2 NaCI 0.5
STPP 0.08 STPP _
Water balance Water balance
pH 11.5 pH 11.5
Total cation molarity0.069 Total cation molarity0.112
Log reduction 7 @ 1 minute Log reduction E-Coli7 @ 1 minute
E-Coli
R
Nominal Wt
Sodium Lauryl 0.2
Sulfate
Oleic acid 0.05
NaHC 03 2.0
NaOH 1.3
Ethano 1 4.5
Na2EDTA2Hz0 0.003
Citric acid ~ 0.54
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Grapefruit oil 0.05
Water balance
pH 11.5
Total cation molarity 0.569
Log reduction E-Goli >> @ 0.5 minute
STPP is sodium tripolyphosphate and PEG is polyethylene glycol with the
indicated molecular weight.
A pleasant citrus odor in solution can also be obtained by using citrus
extracts
such as Lime 63 or distilled Grapefruit oil which are food grade
flavorants/perfumes.
Produce washed in the soak solutions are determined to have no negative
effects
on it in regards to taste or palatability even without a rinse.
