CA1131061A - Intermediate moisture food compositions containing 1,3-diols and diol esters - Google Patents

Abstract

U.S. 90,135 ABSTRACT OF THE DISCLOSURE

Intermediate moisture food products are prepared utilizing 1.3-diols and their esters for inhibiting microbial growth.

Description

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The present inventlon i8 concerned generally with in~ermediate mQisture food compositions, which composi~ions contain as an ingredient a multipurpose compound selected from the class of aliphatic diols and alipha~lc diol esters, The additives of the present lnvention are parti-cularly desirable since they combine effec~iveness with desirable physical proper~ies and are nontoxic~ These multipurpose additives are particularly effective for the inhibition of bacterial growth and for preventing yeast and mold grow~h.
During the pas~ decade, considerable progress has been made in the development of intermediate moisture food compositions. These inter-mediate moisture food compositions comprise a heterogeneous group of foods which resemble dry foods in their resistance to microbactsrial deteriora-tion but which contain æufficien~ moisture that they canno~ be considered as dry foods. Generally, the intermediate moisture foods are plastic and sre eaQily masticated bu~ do not produce an oral feeling of dryness. Not~
withstanding their microbiological stabllity, intermediate moisture foDds are sub~ect to the same types of adverse chemlcal changes as observed with ~ully dehydra~ad foods. As a generalizaeion, foods in the intermediate moisture range are more susceptible to the Maillard reaction than "dry"
foods but less susceptible to fat oxidation.
The availability of water for spore germination and microbial growth is closely related to its relative vapor pressure, commonly~
designated as water activity. Water activity (Aw) is defined as the ratio of the vapor pressure (P) of water in the food to the vapor pressure of pure water (PO) at the same temperature. Within the range favorablè ~o the growth of mesophilic microorganisms, Aw is practically independent of ~emperature.
In generalS ~he intermediate moisture foods with which the present invention is concerned have a total water content in the range from about 20% to 50% by weight. However, thls water is present ln a form not readily available to microbes in that the "water activity" of ~L~3~C~6~

the food is low. As pointed out heretofore, "water acti~ity" is defined by ~he following equation:
w P/PO = ERH/100 Aw = "water activity"
P = partial pressure of water ln food PO = sa~uration pressure of water at specified temperature ERH = equilibrium relative humidity The "wa~er activity" of the foods with which the present invention is concerned is in the range of 0~5 to 0.9, preferably in the range from 0.6 to 0.85, such as abou~ 0.7. Generally9 a water activity below about 0.85 will prevent the growth of bacteria, while a water activity below about 0.8 will prevent tile growth of yeast. Molds are mos~ resistant to a lower water activity, so~ne showing growth in a media w~h a water activity as low as about 0.60.
The pH of the intermediate food compositions of the present invention is in the range of about 3.5 to 8.0, preferably 4.0 to 6Ø
If the pH is above about 6.0, the g~ow h of the microorganism is dif~icult to control.
The intermediate moisture food compositions presently marketed are rendered stable against deterioration by incorporating into the pre-pared food one or more representatives of each of two types of ingre-dients~ namely:
(1) An osmotic agent such as salt, sugar, glycerol and the like which has the effect of depressing the "water activity1' of the food to levels at which most bacteria and yeasts will not grow; and (2~ A mycostatic agent such as sorbic or propionic acids or their salts, which prevent~ the growth of certain ~olds and yeasts that are not readily inhibited bg the osmotic agents.
Thus, unless these agents are added, most intermediate moisture foods are highly susceptible to spoilage due to the action oP bacteria, yeast and molds.

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Prior methods of preserving foods by freezing and canning are very expensive. Frozen foods require freezer space for storage and usually cannot be refrozen, and are also less palatable than fresh or canned foods. Dried foods mus~ be rehydrated before consumption and, in most cases, the rehydrated product is not so desirable organoleptically as the original fresh food. Thus, intermediate moisture foods provide an attractive alternative to prior conven~ional methods of food preservationO
They are more convenient to use, require no special storage facilities and are potentially less expensive. When properly formulated, these foods have a high degree of palatability.
However, the develop~ent of $ntermediate mois~ure foods has been retarded because of the lack of suitable chemical additlves. Des~rable preserva~ives, in addltion to being effective in controlling water activity and suppressing mold growth, must be safe to use, preferably nutritious, and must impart no undesirable fLavor, texture or other organoleptic qualities to the finished product. The preservatives com-monly used today, as hereinbefore mentioned, are deficient in one or more of these requirPmen~s. For example, sugar, glycerol and propylene glycol are only moderately efective in controlling water activity and must be used at high levels in the food formulations. At these levels, these compounds add to the cost of the product and tend to impart an undesirable swee~ flavor to the preparation. Propylene glycol, for example, is too toxic for use in the amounts required. A salt, such as sodium chloride, is effective but generally cannot be added at high enough levels in foods because of the sal~y taste and other undesirable qualities it imparts.
Sugars, such as ucrose, are no~ only too sweet for soft-moist food formula~ions but also present another difficulty due to their tendency to promote nonenzymatic browning. Non-enzymatic browning is caused by complex reactions between the amino groups of proteins and the keto groups of sugars (the "Maillard Reaction"). This leads to unde-~irable darkening of the food product as well as off~odors and flavors.

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Such interactions can ~lso reduce the nutritional va~ue of foods.
The above-enumerated osmotic agents have very lit~le mycos~atic action and a separate mold inhibitor ~ust be added. Commonly sorbic acid, propionlc acid or their salts are employed. These additives can only be used at low levels. In add1tion~ being acids, they are less effective at neutral pH where many ood products must be maintained.
It has now been discovered that certain aliphatic 1,3-diols containing 4 to 15 carbon atoms in the aliphatic chaln and their ester6 are superior additives for soft-moist foods. ~hen added eO various food preparations, whe~her alone or in con~unction wi~h one or more of ~he above-named che~icals, these particular diols impart many very desirable quallties to ~he food produc~. These particular diols ma~ntain such pre-parations in a bacteria-, yeast- and mold-free s~ate, thereby ~ncreasing the shelf life of the product. In addition, they provide softness, or plasticity and enhance the palatability of food formulations. By re-placin~ all or part o the sal~, glycerol or sugar in current inter~ediate mo~sture foods, these diols obviate ehe difficul~ies caused by the strong flavo~s of such compounds and reduce ~he incidence of nonenzyma~ic brown~ng. Finally, they are completely metabolized and actually improve the nutritive properties of the intermediate moistur foods in which they are incorporated.
The linear lJ3-diols or esters contain from about 4 ~o 15 carbon atoms in the diol portion of the molecule, preferably aboue 4 to about 10 carbon atoms in the molecule. The es~er portions of the molecule contain from 2 to 20 carbon at~ms, preferably from sbout 3 to 10 carbon atoms.
The polyol~ of the present invention contain hydroxy groups on at least the first and third carbon atoms of th~ molecule. It is this 1,3-di-hydroxy configuratlon which renders these compounds very useful as food additives because of their inherent safety. Polyalcohols with hydroxyl groups ~ other positions on the carbon chain are more toxic and, there-fore, are less useful as additives. In addition to being non~oxic and readily metabolized, the 1,3-diols and esters claimed herein have certain o~her advantages~ making them highly desirable as additives for "inter-mediate-moisture" or "soft-moist foods~ they are stable, non-volatile oils and have a long storage and shelf life, ~2~ they have an appreciable water solubllity and are readily emulsified, making them easy to formulate in various food preparatlons; (3) they are readily absorbed in the intestinal tract and they are completely metabolized~
A summary of the compounds specifically claimed in this invention, along with their caloric denslties and some of their physical pr~perties, is presented in Tables I and II. This invention is not limited to these specific compounds. Any 1,3-diol containing 4 to 15 carbon atoms or its mono- or diester is useful for one or more applica-tions a3 additives for intermedia~e mois~ure foods.

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TABLE I
Theoretical Caloric Taste Density Diol BP¦mm (C.) Odor, etc~
1,3-butanediol 202-203 Colorless, 6.7 sweet odor, bitter taste 1,3-pentanediol 78~ 0.5 Colorless, 7.4 s~eet odor, bitter ~as~e 1,3-hexanediol 81-8210.2 Colorless, 7.8 slight musty odor, bit~er taste 1,3-heptanediol 90/0.5 Colorless, 8.2 slight musty odor, slight bitter taste 1,3-octanediol 87-89/0.3 Colorless, 8.5 slight musty odor, slight bitter taste 1,3-nonanediol 126/1.1 Colorless, 8.7 slight musty odor, slight bitter taste 1,3~decanediol mp(2)~30-31 Colorless, 8.9 slight musty odor, slight bitter taste 1,3-undecanediol mp(2)~41-~2 Colorless, 9.1 slight musty odor, slight bitter taste (l)Caloric density is the theoretically available energy in kilocalories per gram of the compound.

2) mp = melting poin~.

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The bes~ esters are those wi~h 5 to 8 carbon hydrocarbon "tail"
in ei~her the diol or ester portion of the compound combined with a concentratlon of polar groups in another part o~ the molecule, as, for example, 1,3-octanediol-1-monopropionate or 1,3-butanediol-1-m~nooctanoate.
Some especially valuab~e esters are shown in the following Table II.
T~BLE II
PROPERTIES OF SO~ 1 3-DIOL ESTERS
~ , Rat Feedin~_Results o Caloric Density (Kcal/g3 Compound _ BP C. _serbed ~a~e~ Uti~ized 101,3-Butanediol (parent diol) 1-monopropionate 1-monoctanoate 90-95 (0~3) 1-monopalmitate MP* 3 29-31 dipropionate 67-70 (0.4) 1,3-Hexanediol --1-monoacetate 59~62 (0.15) 6.7 7.0 95 1-monooctanoate 117 122 tO.3) 8.4 9.0 95 1-monopalmitate 124-126 (Q.2) 7.3 9.3 78 diacetate 81-82 (0.9) 1,3-~eptanediol 1-mo~ooctanoa~e 85--90 ~l.O~
1-monopalmitate MP* ~ 30-39 dipropionate 90-92 (0.4 201~3-Octanediol 1-monopropionate 83-86 (0.3 MP ~ melting point.
The diol and diol esters of the present invention may be pre-pared by any suitable technique such as by the Reformatsky reaction followed by reduction, or by means of the Prins reaction of f~nmaldehyde and the appropriate olefin.
The amoun~ of diol and diol ester used may vary widely, depend-ing upo~ the particular d~ol or diol ester employed. Ge~erally, abdut 0.05% to 50% by weight of the diol or diol ester may be used~ based vn the ~otal food composi~ion. If the diol be a lower member ~uch as 6~

1,3-bu~anediol or 1,3-pentanediol 3 it is preferred to use 5~0% to 50% by weight, preferably 15% to 40%, such as 2U% to 25% by weight based on the total food composi~ion.
Also, the a~ount used will depend to some ex~ent upon the pH
of the intermediate mois~ure food co~position. Thus, if the pH is in the range of about 7.5 to 8.5, about 25% by weight of pentanediol or butanediol will be used.
If an ester of bueanediol or pentanediol is usedy it is pre~
ferred that the a~ount used be in the range from about 0.05 to 5.0% by 13 weight based on the total food composition.
Also, if the diol be a higher member such as a heptanediol, or a higher diol or an ester of such diols, it is preferred that the con-centration be in the range from about 0.05 to 5.0% by weight based on the total food compositlon.
With respect to certain foods having a high pH, above about 5,0, it is very desirable to utilize a mixt-lre of diols, such as 1,3-butanediol and 1,3-heptanediol. This diol mixture is in the range from about 75% butanediol ~o 99% bu~anediol, as compared to 1% heptanediol ~o 25% heptanediol. A very desirable dlol mixture comprises about 9S~
butanediol and 5% heptanediol. This mixture is used in the range of 5%
~o 50% by weight9 based on the total food composition.
Although all the compounds listed in Tables I and II are valuable as addieives for ~ntermedlate moisture or soft-moist foods~
some are more valuable for certain purposes than others. For example, ~he lower members of the diol series, 1,3-butanediol and 1,3-pentanediol are excellent humectants, plasticizers and are useful for controlling water activity when used in a concentration of 5 to 50% by weightO They can, therefore, be used to replace all or part of the salt, sugar, glycerol or propylene glycol which are conventionally used as osmotic agents in the soft-moist formulations. These lower 1,3-diols also possess weak ~ycostatic action. In some formulationst they may be used ~3~

without added mold inhibi~ors. This gives them a clear-cut advantage over salt, sugar, glycerol or propylene glycol systems where mycostats must always be added. In food fosmulations more conducive ~o mold growth, it is desirable to include a mold inhibitor in the 1,3-bu~ane-diol or 1,3-pentanediol systems. Any safe mycostat, for example, pro-pionic acid or sorbic acid may be used. If so, a reduced quankity of such inhibitors can be used compared to the salt, sugar, glycerol or propylene glycol systems.
A very desirable method to enhance the mycostatic action of 133-butane or 1,3-pentanediol formulations is by addition of abou~ 0.5%
to 3% by weight9 based on diol ~ixture, of a 1,3-diol of 6 or more carbon atoms as, for example, 1,3~heptanediol, or one of the diol esters as, for example, 1,3-oct~nediol-1-monopropionate. These compounds are superior mold lnhibitors. They have been shown to be significantly more effective ~han sorbic acid, propionic acid Ol their sal~s. These diols and esters are also effective a~ neutral or high pH where the mold-inhibiting action of organic acids is greatly reduced. An additional advantag~ i~ that these diols and esters are less toxic and more nutri-tious than sorbic or propionic acids.
As heretofore mentioned, a very desirable preservative system is obtained by using a mixture of a lower 1,3-diol, for example, 1,3-pentanediol and an ester of a 1,3-pentanediol. Another desirable system is butanediol and an ester of butanediol 9 æuch as 1,3-butanediol-1-monopropionate. Another very desirable system or mixture is 1,3-bueane-diol and 193-heptanediol. Although each type of compound is valuable by itselfg the combination of the two has unique properties as a pre-servative system. The percentage of the two type~ will vary, depending upon the food system involved. Normally the lower diol, serving principally as an osmotic agent, would comprise from about 75 to 99% of the mixture while the higher diol or ester would comprise 1 to 25%. A
very desirable mixture is one containing 90% by weight of the lower diol.

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The level that such a mixture would be used in a given soft-moist food formulation would range from about 5~ to about 50X, preferably from about 20% to 25% by weight.
In order to further illus~rate the invention, various tests were carried out, the results of which are described in the following examples and tables of da~. In Table IIA are summari~ed the re~ults of toxicity measurements and nutritlonal evaluations for a variety of di-hydroxy compounds including 1,3-diols, These studies were conducted wilth rats~
The "observed metabolic energy" values shown in Table IIA ~ere obtained by feeding test groups, of 5-10 rats each, various amounts of several high energy supplements including the 1,3-diols. The basal diets in each case ~ontained sufficient protein, salts9 vitamins and minsrals to support normal growth. However, the basal diets were deficient in energy (calories). This deficit was, in part, overcome by adding varying amounts of the polyols or of natural energy sources of known caloric densities such as lard, sucrose, or glucose. Curves were drawn by plott-ing the ~verage change in body welght of test animals against the amount of high energy supplemene tested and ~traight lines were ob~ained. The slopes of the lines ase measures of the energy values of the test com-pounds. The values given in Table IIA were obtalned by measuring the slopes of ~he lines of ehe test compound3 and comparlng them w~th the 610pes of the lines obtalned with ~he standards ~lard, glucose or sucrose whose caloric densities are 9,3 Kcsl/gm, 3.8 ~cal/gm and 4.1 Kc~l/gm, respec~ively). The 'lobserved metabolic energy" values were calc~lated according tD the formula:

Rcal/gm of Unknown - Slope of unknown line X K~al/gm of standard Slope of standard line The "observed" metabolic energy" of a material is a measure of its nutritional valueO The h~gher the energy the grea~er its value. It is clear from the results given in Table IIA that 1,3-diols are very de~irable food components from a nutritional standpoint. Other dihydroxy compounds, however, are not useful nutrients.

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I,D50 values are a common measure of the toxicity of 8 compound.
These LD50 values represent the lethal dose for a 50% kill of ~he animals tested per unit weight of the animals. The higher the I.D50 value~ the lower the toxicity. The data in Table IIA establish that the 1,3-con~
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The LD50 values given in Table IIA were obtained by giving test animals graded single doses of the test compounds orally and observing them for one wee~ The n~mber of deaths ln each group was notea and the dose required for a 50% kill taken as the LD~o value. In many cases, no death occurred even a~ the 20 g/kg level (about as much as one can give a rat in one dose), hence the basis of the ~'~2n~ values shown in the table.

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The toxicity data with respect to the esters are given in the following Table III. The LD50 values for some common food preservatives are also shown. All are significantly more toxic (lower LD50 values) than either the diols or the esters.
TABLE III
TOXICITY DArA
PreservativeOral LD50 (Rats~
Diol Esters ~ 20 g/Kg (propionates and higher) Sorbic acld 10 g/Kg Sodium sorbate 6-7 g¦Kg Propionic acid 4 g/Kg Sodium benzoate2 2-3 g/Kg LD = lethal dose f or 50% kill.
Source: ~andbook of Toxicology, Vol. I, W.S. Spector, ed" WADC Tech. Rept. #55-16, National Academy of Sciences, National Research Council (1955).
3Source: H.F. Smyth et al., Am. Ind. Hyg. Assoc. J., 23, 95 (1962~.
In order to further illustrate this inven~lon and, in par~i-cular, to establish the superiority of the 1,3-diols and esters as bacteriostats and mold inhibieors, the ~ollowing microbiological tes~s were conducted.

Nutrien~ broth was used as the basal nutrient medium for the growth of all mlcroorganis~s tested. Five ml. of nutrien~ broth medium (Difco Co.) were placed in 18 mm x 150 mm test tubes and the basal medium sterilized with s~eam at 15 psi for 15 mlnu~es. After cooling, a sufi~ient amount of the various compounds were added to the basal medium to give the concentrations used. Normally a final concentration o 0l2>
1 and 2% were used.
After mixing the chemicals with nutrient broth, the tubes were lnoculated with the various test microorganlsms~ The test mi~rooreanisms ~ 14 .~,................................................... .

were gro~n 25 hours earlier in n~trient broth and 1 drop of the dense microbial s~spension was added to the tubes.
The tubes con~aining the chemicals and m-lcroorganisms were then incubated at the optimal grow~h temperature reported for each micro-organism tested. Either 37C~ or 30C. was used. Growth in control tubes, as well as those containing chemicals, was observed visually.
After a suitable incubation period~ a small aliquot of the ~es~ solutions was streaked on an agar plate. ~his was done in order to confirm the visual readings of the presence of microbial growth.
The results are shown in Tables IV and V. The "minimum effec-tive concentration" is the lowest concentration of additive which efectively prevented growth under the conditions of the test.
TABLE IV
PRESER~ATIVE ACTION AGAINST BACTERIA
... . ..... .~ .
Minimum Effective Concentration A~inst = ~
Salmonella _ CompoundStaph. aure~s Typhimurium E coli 1~3-Heptanediol 2% 1% 1%

1,3-Octanediol~
monopropionte + 0.2% 2%

1,3-Butanediol-dipropionate + 0.2%
K--sorbate ~ 2% +
Cz-propionate Symbols~ ~ - no effect at 2~.
O = not testedO
I~ is apparent from ~he above that the effeetlveness of these materials ag~inst a ~ide speetrum of bacteria is established by the typical d~ta shown in Table IY. In these tests the test compounds are compared to the known co~mercial preservatives9 potassiu~ sorbate and calcium propionate, as to their ability to inhibit growth of various bacteria. It is apparent that several of the compounds are effective at lower concentrations than either of the current additives. Of especial interest is the result ~hat some of the test compounds are ac~ive against ~ 15 -Salmonella at levels as low as 0.2%. These tests were carried out under conditions conducive to prolific growth of the organisms. Under con-ditions of normal food storage9 the test compounds would be effective at even lower levels. Potassium sorbate was inhibitory in this test only at ~% or above under the test conditions and calci~m propionate did not inhibit growth even at the 2% level. Salmonellae are impor~ant public health organisms frequently found in foods, especially meat, eggs, and dairy products. All members of ~he genus are considered as human pathogens.
The present additives are also very effective with respect to mold inhibition which is shown in the following Table V.

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In Table Y ~ome selected diols and es~ers are compared with potassium sorba~e and calcium proplonate, commercial mold inhibitors7 in effectiveness against various eommon molds. The lower the "minimum"
effec~ive concentration, the more effective the compound. I~ is apparen~
that several of the test compounds are significantly better than the currently used preservatives.

In addition to these ~sts, some more definitive s~udies were conducted to determine the effectiveness of certain diols and es~ers in inhibiting the growth of two common molds under various c~lture conditions.
The~e tests were carried out as described above except tha~ the pH was varied by the use of suitable buffering agents and, in some experiments, either dextrose or glycerol were added to demonstrate the effectiveness of the diols and esters in dif~erent growth media. Molds were chose~
becsuse they were of especial impor~ance in the spoilage of intermediate moisture food~.
For purposes of comparison, severa3. co~mercial food preserva-~ives were tested under ~he same conditions. The results are show~ in Table~ VI and VII. It is apparent from these data that the diols and esters are significan~ly more effective than the commercial additives, Of especial importance is the finding (Tables VI and VII) that 1,3-heptanediol and the esters are highly active inhibitors of molds, typified by A. niger and P. roquefortii at a pH of 6.8 ~nearly neutral) where com-merclal additives are either only slightly effectlve or ineffectiYe. This is very impor~ant for the preservation of many foods where the pH of the preparation mus~ be near neutrality.
It is apparen~ from the results of the nutritional and micro-biological studies described above that 1~3-dlols and their esters are safe and effective antimicrobial preservatives.

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To illustrate ~he invention s~ill further some typical inter-mediate moisture food preparations were formulated, various preservative systems were added~ the foods were inoculated with microorganisms and were stored at 37C. for several weeks. The products were then evaluated for the presence o~ organism grow~h~ The formulations consisted of:
1. Apple Flakes, pH ~ 4.4 Dehydra~ed apple flakes24 g.
Sucrose 26 g.
Starch 4Q5 g.
Water 104.5 g.
Preservatives (various quant.; see Table VIII) 2. Banana, pH - 4.5 Strained banana baby food wt~apioca (20% solids) Preservatives (various amounts; see Table IX) 3. _Chicken Baby Food, pH = 6.5 S~rained chicken w/broth (22% solids) Preservatives (various amounts; see Table X) The results of these tests are summarized in the fnllowing Tables VIII, IX and X.

at6~

_ABLE VIII
PL~ FLAKES
pH - 4.4 Microorganism Pre~etvative 1. 20% Glycerol +
2. 10% 1,3-Butanediol 3. 2% 1~3-Butanediol +

4. 0.3% Propylene Glycol +

5. 0.3~ Potassium Sorbate

6. 0.3X 1,3-Hep~anediol

7. 0.3~ 1,3-Octanediol-l-monopropionate B~ 0.3% 1,3-Butanediol-l-monooctanoate TABLE IX
BANANA BABY FOOD
:

Microorganism Prerervative Growth (~) or No Growth t-) 1. Glycerol +
2. 10% 1~3-Butanediol 3, 0.5~ 1,3-Heptanediol -4. O. 5æ 1,3-Octanediol-l-monoproplonate 5. 0.1% Potassium Sorbate *Lower leYsls no~ tes~ed~

'.

;196~1 TABLE ~

CHICK~ BABY FOOD
.
pH -_6.5 Microorganism Preservative Growth (+) or No Growth t-) 1. 25~ Glycerol 2. 25% 1,3-Butanediol 3. 25% Glycerol 4. ~ 0.3% Potassium So~hate +
5. ~ 3~ 1,3-Butanediol ~- ~ 0.2X 1,3-Heptanediol 7. ~ 0.5% 193-Octanediol-1-monopropionate

8. + 1% 1,3-Butanediol-l*
monopropionate

9. ~ 0.3% Potas6ium Sorbate -~
2% Propylene Glycol ~ ;

10. ~ 0.3% Potassium Sorbate 2% 1,3~Butanediol *Lower levels not tested.
The foregoing results clearly establish the superiority of the preservatives and preservatives claimed in this invention. In a typical low pH system (Table VIII) which is relatively easy to preserve, 1,3-butanediol was clearly superior to glycerol as an osmot~c agent. The diol prevented growth of organi~ms at ~he 10% level while 20% of the glycerol was ineffective (Table VIII, entries 1 and 2)o In additlon, 1,3~heptanediol and ~he two diol esters were at least as effective as the recognized preservative, potassium sorbate, and more effective than propylene glycol.
Si~ilar conclusions can be drawn from the data on the banana baby food tests (Table IX). ~ere 10X 1,3-bu~anediol was effective while an equal concentra~ion of glycerol was not (entries 1 and 2). Also, 1,3~heptanediol and 1,3-octanediol-1-monopropionate were effective at very low levels tentries 3 and 4).

6J6~

The superiority of the present compounds as preservatives is especially clear from the results of tests with the high pH chicken baby food sys~em (Table X). Again, 193 butanediol was clearly more effec~ive than glycerol ~entry 2 vs. en~ry 1). The commonly-used combination of 2% propylene glycol ~ 0.3% potassium sorbate (entry 9, Table X) was not able to prevent gro~th, bu~ 2Z 1,3-butanediol ~ 0.3% potassium sorbate (entry 10) was. This indicates the superiority of 1,3-b~tanediol over propylene glycol. Of especial interest is the f~ct tha~ 0.2% of 133-heptanediol (en.ry 6) and 0~5% of 1,3-octanediol-1-monopropionate (entry 7) completely inhibited growth while the sample containing 0.3% of potasslum sorbate (entry 4) showed heavy gro~th.
From the foregoing data and examples it is apparent that 193-dlols and their esters, alone or in combinat:Lon, provide safe, nu~ritious and highly-effective systems for the preservation of intermediate mvisture foodsO
Some typical intermediate moisture food formulations, other than those given above, which ill~strate the use of 1,3-diols and 1,3- :
diol esters axe as follo~s:

2~

~L39~ 6~

GROUP I
~se of Diols and Esters as Diced Carrots (Formulation 13 Weight X
Range Preferred Diced~ cooked carrots (sol~ds) 6-10 8 Water 48-55 48 1,3-Butanediol* 40-45 42 Sal~ 1.5-2.5 1.7 1,3-Heptanediol or diol este~** 0.1-0.5 0.3 *Replaces 35% to 50% of glycerol which imparts a bad taste and/or sucrose which causes over-sweetness andlor salt whlch causes a salty taste.
**Replaces 0.5% of potass~um sorbate.
M~at Sauce tFormulat on 2?
Weight %
Range Preferr~d Catsup 20-25 23 :~
~a~er 10-20 15.5 Vinegar 12-14 13.5 Sucrose 10-13 12 Starch hydrolysste - 15 DE 4-5 4.5 Salt 2-3 2.5 Cornstarch 2-3 2.5 Monosodium glutamate 1-2 ~ustard powder 0.2 002 Onion powder qs qs Garlic powder qs qs 1,3-Butanediol* 20-30 25 1,3-Heptanediol or diol es~er** 0.1-0.5 0.3 * Replaces 20% to 35% glycerol ** Replaces 0.5% of pntassiw~ sorbate ~3~

Chunk l'una (Formulation 3) Wei~ht %
Range Preferred Tuna chunks 20-30 26.5 Water 40-50 46.5 Sal~ 2-3 2.5 1~3-Butanediol* 20-30 2~.0 1,3-Hep~anediol or diol ester** 0~3~1.5 0.5 * Replaees 30% glycerol ** Replaces 0.7 potassium sorbate Macaroni (Formulation 4) Weight % _ Ran~e Preferred Cooked elbow macaroni 20-25 22.S
~ater 30_4~ 37 5 Salt 4-8 7 1,3-Butanediol* 25-35 32,5 1,3-Heptanediol or diol ester** 0.3~1.5 0.5 * Replaces 35X ~lycerol ** Replaces 0~5 potassium sorbat~

Th¢se foods may be formulated in any way desired. One especially desirable way is to cook~ or cold soak the food in a solution of the additives of predetermined compositio~ to leaYe the des~red con-centration of additives after drainage, then drain and hold overnight in a refrigerator.

j - 28 -~3~

GRO~P II
Formulations which Employ Diols and Esters in Con~unction with Other Osmotic Agents (Formulation 5) V ~
Range Preferred Diced~ cooked carrots ~10% so~ids~ 50-70 65 Sugar ~Sucrose) 15-35 20 1,3-Bu~anediol* 0-15 13 Salt 1~2 1.7 1,3-Heptanediol or diol ester** 0~1-0.3 0.3 * Replaces 15% sucrose~
** Replaces 0.5 potassium sorbate.
Breakfast Tsrt Fllling (Formula~ion 6? _ _ _ Range Preferred ~ater 30-40 38 Vacuum dried apples (or other fruit)10-lS 12 .
Sugar (Sucrose) 0-35 30 1,3-Butanediol* 0-2S 18 St~roh 1-2 1.5 Sulfite (sod~um salt~ -- 0.03 1,3-Heptanediol or diol esker** 0.1-1 0.5 * Replaces 20% sucrose and/or glycerol.
** Replaces 0.5 potasslum sorbate.
The above food compositions are lntended for human consumption~
However, 1,3-diols and dlol esters are especially valuable as additives for animal feeds, for example, pet foods.
A typical soft moist pet food is as follows:

~L~3~

Soft Moist Pet Food (Formulatlon 7) Ingredients Parts by Weigh~
Tripe 18.0 10~30 Fish (~hole cod and smele) 6 0 4-8 Beef chee~ tr~mmings 6.0 3-9 Soy flakes 31.5 20-40 Dry cor~ syrup solids (42 DE~11.4 5-25 Soy hulls 3.0 0.5-6.0 Dry nonfat ailk sollds 205 0.5-6.0 Bone meal 2.1 0.5-5.0 ~:lcalcium phosphate 1,4 0.2-3.0 1,3-Butanediol* 13.0 2.0-15.0 Sorbitol 1.0 0.5-60 Tallow 2.0 0.5-60 Mono- and diglycerides 1.0 0.2-3.0 Sodium chloride 0.6 0.1-2.0 1,3-Heptanediol or diol ester**0.3 0.1-1.0 Minerals9 vitamins3 color, e~c. 0.3 0.1-1.0 * Replaces 10~ corn syrup, 1% sorbitol and all propylene glycol.
** Replaces D.32 potassi~m sorbate.
Current pet foods contain large amounts of sucrose ~hich lmpart~ a sweet taste to the meat, ob~ectionable to ~any pets. 1,3-diols avoid ~hat by cuttIng down on the sugar.
The antimycotic sys~e~ in current pet foods is propylene glycol and sorbic ac~d. A lower 193-diol and a hlgher 1,3-diol or a diol ester is a more effective system. Another typical pet food formulation is as follows:

6~

Pet Food - Direct ~ix tPormulation 8) Weight ~
Range Prefetted Meat and Meat By-Products 25~50 35.0 Soy Flakes 20-50 35.0 5ucrose 5-40 10.0 1,3-Butanediol* 5-40 10.0 Milk Solids 2-8 4.0 Fat 1-3 2~0 Salt 1-3 2,0 F D ~ C Red Dye 0.006-1.0 0.5 Vitami~ Minersl Mix 0.06-1.0 0.5 Eseer of 1,3-d~ol 0.1-2 1.0 100.0 * Replaces 10~ sucrose and all of the glycerol.
Other typical food formulations are as follows:

~0 , ` :

.. ~ , .

3L~L3~

Mea~g Fish or Poultry Chunks ~Formulatin 9? -- .
A. Cook-Soak Method .
Cooked, Drained Chunks: 1 Part Infusion Solution: 2 Parts Composition of Infusion Solution _ ~ei~ht %
Range~referred Cream Soup Base 5~20 15 Sugar (Sucrose) 0 50 15-20 1,3-Butanediol 0~50 30~35*
Salt 0-2 1 2 1,3-Heptanediol or D~ol Ester 0.1-1,0 0.5 *Preferred amount depends on type of meat. Replaces 30%-40~ sucrose.
Procedure: Chunks sre soaked i~ ln~usion solution for a short time, then drained and packaged.
B Freeze Dried ~ethod (Formulation 10) Freeæe Dried Meat Chunks: 1 Part Rehydration Sol~tion: 3 Par~s Composition o~ Reh~dration Solution ei~ht %
Ran~e Preferred Water 5-2010-i8 Sugar (Sucros~ 5-2010-15 ~,3-B~tanediol 5-4025-30*
1,3-Heptanediol or Diol ~ster 0.1-1.0 0.5 Salt qs qs *Preferred amount depends on type of meat, fish or poultry u~ed. ~eplaces sucrose.
Procedure: Free~e dried chunks are rehydrated in solution for approximately fi~e minutes or until water content reaches desired r~nge (25-50%).

w 32 -~L~3~(~6~

Meat, Fish or Chicken Chunks _ (Formulation 11) A. Cook-Soak Me~hod Weight %
~ Preferred Cooked~ Drained Chunks So~k Solueion Soup Base 5-40 18 Sugar 0~60 40 1,3-Butanediol* 0-60 40 Salt 0-2 1.0 1~ E~ter 0.1-~ 1.0 * Replaces 40% sucro~e.
Procedure: Mix 1 Pt Chick~n/2 Pt Solution B. Freeze Dried Method (Formulation 12 Wei~ht 7 RangePreferred Solution for Rehydration ;~
~ater 5~50 33.0 Sugar 5-5Q 33. n 1,3-Butanediol* 5-50 33,0 2~ ~ Ester 0.1-2.0 1 0 * Replsces 30%-40~ sucro~eO
Procedure: Mix 1 Pt Meat/3 Pts Solution.

Claims (13)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An intermediate moisture food product having a water content in the range of from about 20% to about 60%, a water activity in the range of 0.5 to 0.9, and a pH in the range of about 3.5 to 8.0, said food composition having from about 0,05% to about 50% by weight of an additive selected from linear aliphatic 1,3-diols having 7 to 15 carbon atoms in the chain, mixtures of said diols, esters of linear aliphatic 1,3-diols having 4 to 15 carbon atoms in the chain and linear aliphatic acyl groups of 2 to 20 carbon atoms, and mixtures of said esters and linear aliphatic 1,3-diols having 4 to 15 carbon atoms in the chain,

2. The food product of claim 1 wherein said ester contains from about 3 to 10 carbon atoms in the acyl group.

3. The food product of claim 1 wherein said additive is a mixture of said diols.

4. The food product of claim 1 wherein the additive is a 1,3-diol having 7-15 carbon atoms in the aliphatic chain and is present in a concentration of about 0.5% to about 5% by weight.

5 . The food product of claim 4 wherein said diol is 1,3-heptanediol.

6. The food product of claim 4 wherein said diol is 1,3-nonanediol.

7. The food product of claim 1 wherein the additive is an ester of a linear aliphatic 1,3-diol having 4 to 6 carbon atoms in the chain and a linear ali-phatic acyl group of 2 to 20 carbon atoms.

8. The food product of claim 1 wherein the additive is said mixture of diols and esters .

9. The food product of claim 7 or 8 wherein the additive is present in an amount of 0.05 to 5% by weight.

10. The food product of claim 8 wherein said additive is a mixture of 1,3-butanediol and 1,3-octanediol-1-monopropionate.

11. The food product of claim 8 wherein said additive is a mixture of 1,3-butanediol and 1,3-butanediol-1-monooctanoate.

12. The food product of claim 1 including not more than about 20% by weight of an osmotic agent selected from the group consisting of sucrose, glycerol and salt.

13. The food product of claim 1 including not more than 10% by weight of an osmotic agent selected from the group consisting of sucrose, glycerol and salt.