United States Patent 3,795,627 STABLE LIQUID R COMPOSITION Roy K. Langhans, Newark, and Gary A. Sunshine, Wilmington, DeL, assignors to ICI America Inc. No Drawing. Filed June 4, 1971, Ser. No. 150,194
- Int. Cl. B01f 17/34 US. Cl. 252356 8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to clear liquid emulsifier compositions and to yeast-raised baked products prepared with liquid emulsifier compositions. More particularly, this invention relates to stable, clear liquid emulsifier compositions which contain a glycerol partial ester as a softener, a polyoxyethylene ester of a glycerol, hexitol, hexitan, or isohexide as a conditioner, and a small quantity of a clarifying and stabilizing agent comprising propylene glycol monooleate. These compositions when incorporated into a yeast-raised baked product condition the dough prior to baking and inhibit the staling of the finished baked product. This invention further relates to methods of preparation of yeast-raised baked products including processes of continuous bread making.
The staling of bread and similar yeast-leavened products is commonly believed to comprise chemical as well as physical changes which occur in the finished product upon storage under normal storageconditions. The factors contributing to such chemical and physical change in the finished product are known to be complex and varied; even yet, not all the contributing factors are completely understood. Whatever may be causing the staling of yeast-raised baked goods upon storage, it is known that the incorporation of certain emulsifiers into the dough prior to baking will cause a retention in softness of the finished product; i.e., will retard staling. Moreover, such agents frequently improve dough condition which facilitates the handling of the dough during the baking process. A number of antistaling agents exist and 'are normally used in the production of yeasbraised baked goods; among these the monoglycerides, or more commonly, a mixture of monoand diglycerides are preferred. In addition to these, antistaling and dough conditioning agents are desired which maybe used at reduced levels or concentrations in the preparation of the baked product to produce a comparable or superior result in the finished product, which are adaptable to both the batch and continuous bread making processes and which would be either an easily flowable'solid or preferably a liquid product with the above properties.
It is, accordingly, an object of the present invention to provide a stable, clear liquid emulsifying composition for use in preparing baked goods having antistaling characteristics equivalent to those produced with non-liquid emulsifier compositions.
It is another object of the present invention to provide emulsifier compositions suitable for use in the continuous production of bread and other baked products which condition the doughs formed therein to improve their 3,795,627 7 Patented Mar. 5, 1 974 workability in the process, which effectively retards the staling of the, final baked products, and which are easy to use during the baking process because of their fluidity.
It is another object to provide clear liquid emulsifier compositions which are stable and clear at temperatures of 70' F. and above.
It is another object of the present invention to provide emulsifier compositions which may be used in either batch or continuous bread making processes and have the efiect of improving the texture of the final baked products.
It is another object to provide an improved process for making bread products.
All of the foregoing objects and still further objects of the present invention may be accomplished by employing novel liquid emulsifier compositions of the present invention.
The compositions which are contemplated by this invention are combinations of highly unsaturated monoglyceride "softeners and polyoxyethylenated derivatives of. fatty acid esters of glycerol, hexitan, hexitol, or isohexide, or fatty acid esters of polyoxyethylenated glycerol, hexitan, hexitol, or isohexide conditioners which are stabilized and clarified by the addition of measured amounts of propylene glycol monoolerate. These products are dif ferent from similar combinations in thatthey are clear liquids and'stable at temperatures above 70' F. Such combinations can be taken to as low as 33' F. and cycled several times from high to low temperatures without separation, gelation, or the formation of precipitates at 70' F.
The weight percents of each component, respectively, within the above emulsifier compositions will be as follows: the propylene glycol partial fatty acid ester from 5 to 90%, the monoglyceride from 0 to 85 weight percent and the polyoxyethylene-oontaining emulsifier from 10 to In a preferred emulsifier composition, wherein the monoglyceride level is 0, the propylene glycol partial fatty acid ester will be present at from 55 to 65 weight percent of the composition and the polyoxyethylenecontaining emulsifier will be present at from 35 to 45 weight percent of the composition. In a preferred threecomponent emulsifier composition, theweight percents of the. propylene glycol partial fatty acid ester will be from 20 to 30, of the polyoxyethylene-containing emulsifier 35 to 45, and of the monoglyceride from 30 to 40 weight percent of the composition.
In addition to'propylene glycol monooleate, other propylene glycol partial fatty acid esters can be used as equivalents but must contain a high level of unsaturation, i.e., the level of unsaturated fatty acid moieties, among the total fatty acid moieties comprising the fatty acid esters of propylene glycol, must be at least 60 and preferably mol percent. Among those fatty acids which can be used in preparing propylene glycol monoesters are oleic acid, linoleic acid, linolenic acid, gadoleic acid, palmitoleic, myristoleic and erucic acid and other comparable unsaturated fatty acids containing from 12 to 22 carbon atoms. Commercially available fatty acids with high percentages of unsaturates are cottonseed oil acids, corn oil acids, tallow acids, and other fatty acid saponification products. In general the propylene glycol partial fatty acid esters of this invention refer not only to-the pure monoester but 'also to mixtures of monoand diesters of propylene glycol wherein the amount of the alpha monoester is at least 35% by weight. In a preferred propylene glycol monoester, the amount of diester will be at most about 15 weight percent. The propylene glycol monoand The term monoglyceride when used in this invention relates to both a pure monoester of glycerin and a mixture of monoesters and diesters of glycerine. The monoglycerides of this invention are at least 86% unsaturates, that is at least 86 mol percent of the fatty acid molecular segment of the monoglyceride comprises unsaturated fatty acids. In 'a preferred embodiment ofthis invention the degree of unsaturation is at least about 88%. Fatty acid monoglycerides which are 100% unsaturated can be employed as well. Unsautrated fatty acid esters which may be employed include the glycerol esters of oleic acid, linoleic acid, vaccenic acid, licanic acid, and cetoleic acid as well as other unsaturated fatty acid esters which contain from about 12 to about 22 carbon atoms. Any saturated fatty acid ester containing from 8 to about 24 carbon atoms may be used in conjunction with the unsaturated fatty acid esters to achieve the desired minimum level of unsaturated fatty acid esters. In general, they will contain at least about 40% and preferably 50- 56% by weight alpha-mono content in the monglycerol ester.
The monoglycerides which may be used in accordance with this invention may be prepared by transesterification, glycerolysis, or direct esterification of glycerine. Transesterification is generally accomplished by mixing suflicient glycerine with a triglyceride so that during the reaction the moles of glycerine to fatty acid are adjusted to achieve the desired amount of monoglyceride with residual triglycerides and diglycerides.
The conditioner which is a constituent of the clear liquid emulsifier blend of the instant application is a hydrophilic emulsifier which is comprised of a class of ethoxylated fatty acid esters of glycerol, hexitol, hexitan, and isohexide, as well as fatty acid esters of ethoxylated hexitan, hexitol, glycerol, and isohexide. More specifically, the class includes the ethoxylated fatty acid monoesters, diesters, and triesters of sorbitol, mannitol, dulcitol, and iditol; and the monoesters and diesters of their corresponding monoand dianhydrides. A preferred class are those wherein the hexitol is sorbitol or the anhydride sorbitan and isosorbide.
The fatty acids which may be used to prepare ethoxylated esters of glycerol, hexitol, hexitan, and isohexide or the esters of ethoxylated hexitol, hexitan, and isohexide are in general those having from about 12 to 22 carbon atoms and comprise such fatty acids as stearic, palmitic, lauric, oleic, behenic, arachidic, and myristic. Saturated fatty acids are preferred. The ethoxylated fatty acid esters of glycerol, hexitol, hexitan, or isohexide or a fatty acid ester of ethoxylated hexitol, hexitan, or isohexide may be prepared in numerous ways such as esterification of sorbitol or glycerine followed by ethoxylation of the resultant ester, or transesterification of sorbitol and ethoxylation of the resultant ester, ethoxylation of sorbitol, sorbitan, or isosorbide and esterification of the product. The following is an example of the preparation of a higher fatty acid partial ester of sorbitol:
EXAMPLE A One mol of sorbitol pellets and 900 ml. of dimethylformamide were placed in a three-necked flask, equipped with thermometer, mechanical stirrer (10 inch), Vigreux column and condenser. The mixture is heated with stirring until the sorbitol is completely dissolved (approximately 34' C.).
12 grams of anhydrous K,CO, is dissolved in 50 to 75 millimeters of methanol in a steam bath and the solution added to the reaction mixture. Methanol is then removed by distillation. (The catalyst may be added as a solid as well as a methanol solution.) After removal of the methanol, two moles of methyl stearate are added and the reaction mixture reacted at 90 C. When approximately 35% methyl stearate is reacted, the temperature can be raised up to 130 to 135 C. The temperature, however, should not exceed 135 C. to avoid anhydrizing the sorbitol.
The reaction time for the different preparations vary from '10 to 12 hours up to several days. Periodically vacuum is applied to remove methanol liberated during the reaction.
The progress of the reaction was followed by taking samples periodically and analyzing for the unreacted methyl stearate by gas liquid chromatography (GLC). When the unreacted methyl stearate was below the solvent was removed under high vacuum, being careful not to exceed C. pot temperature. The analysis of the product is as follows: saponification number 136, hydroxyl number 306, acid number 3.4.
One ml. sample was taken from the reaction mixture and placed in a 25 ml. Erlenmeyer flask, which contained 15 ml. of 10 to 15% sodium chloride solution. The methyl stearate was then extracted with 5 ml. ether and wasanalyzed for GLC with a four-foot 25% diethylene glycol succinate column at 200 C.
In the polyoxyethylene-containing emulsifiers used in the emulsifier blend of this invention, the mol ratios of ethylene oxide to glycerol, hexitan, or isohexide may vary from as low as about 4 to 1 to as high as about 40 to l, and are designated polyoxyethylene(4-40) sorbitol, sorbitan, or-isosorbide, with a 10:1 to 20:1 mol ratio being preferred.
Representative of the polyoxyethylene-containing fatty acid esters are polyoxyethylene sorbitol distearate, polyoxyethylene sorbitan monostearate, polyoxyethylene iso-- sorbide dipalmitate, polyoxyethylene sorbitan distearate,.
polyoxyethylene isosorbide monooleate, polyoxyethylene sorbitol trilaurate, polyoxyethylene sorbitan dibehenate,
polyoxyethylene isosorbide monolinoleate, polyoxyethylene sorbitan, monolaurate, polyoxyethylene mannitan monooleate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitol oleate, polyoxyethylene iditan monostearate, as well as other similar ethoxylated fatty acid esters of hexitols, hexitans, and isohexides or the fatty acid esters of ethoxylated hexitols, hexitans, and
isohexides. Others are polyoxyethylene derivatives of fatty acid monoand diesters of glycerine such as glycerol 'monostearate, glycerol distearate, glycerol monopalmitate, glycerol dipalmitate, glycerol monooleate, glycerol dioleate, and glycerol esters similar to those mentioned forhexitols.
The clearv liquid emulsifier composition of this invention may be prepared by, mixing with suitable agitation and heat a monoglyceride of the kind hereinbefore described, a polyoxyethylene derivative of glycerol, sorbitol, sorbitan, or isosorbide fatty acid ester, or a fatty acid ester of a polyoxyethylene derivative of a sorbitol, sorbitan, or isosorbide mentioned above, and propylene glycol monooleate. The resulting compositions are usually always clear liquids which can be cycled to 33 F. and back to room temperature for several times without forming stable precipitates, gels or separating into two phases.
In order for those skilled in the art to better understand the instant invention, the following non-limiting examples of the emulsifier compositions of this invention are given:
EXAMPLE 1 Emulsifier:
Glycerol esters of unsaturated tallow acids (54 weight percent alpha monoester-89% unsaturated) d Prodendro (.98) Emersol 233LL (propylene oxide condensation product of tallow acids containing 73.5% oleic, 12% palmitoleic,.4% lino- Glycerol esters of unsaturated tallow acids (54 weight percent alpha monoester89% unsaturated) 36 Prodendro (.98) Emersol 233LL 24 Polyoxyethylene(20)sorbitan monostearate 40 Weight and blend EXAMPLE 3 EXAMPLE 4 Glycerol esters of unsaturated tallow acids (54 weight percent alpha monoester-89% unsaturated) 12 Prodendro (.98) Emersol 233LL 48 -Polyoxyethylene(20)sorbitan monostearate 40 EXAMPLE 5 Prodendro (.98) Emersol 233LL 60 Polyoxyethylene(20)sorbitan monostearate 40 EXAMPLE 6 Propylene glycol ester of unsaturated cottonseed oil acids (75% monoester) 54 Polyoxyethylenet12)isosorbide monobehenate 46 EXAMPLE 7 Glycerol ester of unsaturated corn oil acids (60% monoester) Propylene glycol ester of unsaturated soybean oil acids (90% monoester) 15 Polyoxyethylene(20)sorbitol tristearate 50' EXAMPLE 8 Glycerol ester of linseed oil acids (70% monoester) 15 Propylene glycol ester of unsaturated cottonseed oil acids (92% monoester) Polyoxyethylene(18)sorbitan dioleate 65 As hereinbefore stated, the clear liquid emulsifier composition of this invention is easily incorporated into-dough blend may be dispersed in the dough, in the liquid brew or liquid sponge on in the shortening which is generally added to the brew concurrentl with the flour in the continuous dough making process to form the premix dough. Because of the liquid nature of the emulsifier composition of this invention, the metering of the emulsifier into a continuous process or a batch process is more easily facilitated and standard chemical processing equipment may be used in determining the amount of emulsifier added to any particular batch or to be blended with the brew or liquid sponge in a continuous process. Also, since no water need be added to get a fluid emulsifier system when used in a continuous process, better control of the total water added to the bread can be obtained.
The yeast-raised baked products which are contemplated for preparation in accordance with this invention and are embraced within its purview comprise bread and bread-like products which normally contain not more than about 5% by weight of shortening and not more than about 8% by weight of residual unfermented sugar. In preparing bread or yeast-raised baked products in accordance with this invention, the emulsifier composition of this invention is usually incorporated into the dough within a range of about 0.15 to about 3.0 weight percent based upon the weight of the flour and preferably, an amount equivalent to about a 0.5 weight percent based on the weight of the flour in the dough is used.
In order to compare the results of bread prepared with the emulsifier composition of this invention with bread prepared without the emulsifier blend of this composition, a standard procedure and standard bread formula were used. The experimental bread formula a batch process is as follows:
i t which is used as Percent (flour Grams as 100) h lnnr 865. 0 65 wnfar 493. 0 l 37. 2 eas 33. 8 2. 5 Ygast fo 6. 6 0. 5 b n fiour 465 as Snag 106. 3 8 Salt 26. d 2 Shortening 40. 0 3 Non-lat dry milk solids 6 watnr I 28. 2 ma a 3-6. a 0. 25a 5 I Variable, based on Farlnograph absorption. Use 577 H10 in sponge and 43% mo in dough of mm! water present.
Procedure All of the above ingredients are stored atroom tem-= perature (approximately 70 F.). The sponge ingredients are then kneaded in a 12-quart Hobart bowl, utilizing a standard dough hook, for five minutes at a low speed on the Hobart mixer. The yeast and yeast food are dissolved first in part of the sponge water and added as liquids. The sponge (dough) is fermented 4.5 hours at 86?..F. and 75% relative humidity.
-The fermented sponge is then added to the Hobart mixer. The additional water for the dough is then added and half the amount of the flour of the dough is added on topof the water and all other ingredients except the shortening are placed in the Hobart bowl. The ingredients are .mixed two minutes at medium speed on the Hobart mixer. The remaining flour and the shortening are then added and-the dough is mixed for approximately eight minutes on medium speed depending upOn the Farinograph results and the amount of flour used. The dough is then fermented for 20 minutes at 86' F. and 75% relative humidity. After fermentation, the dough is divided into 18-oz. pieces, rounded, placed into bread pans, and allowed a 60-minute proof at 86 F. and 75% relative humidity. At this point the bread is baked for 20 min utes at 425'. -F. The volume of each loaf is then measured in cc. in a loaf volume meter approximately one hour after baking. The loaves are then sealed in plastic bags and stored :at constant conditions (76' F., 50% relative humidity) for a period of six days. After three days and six days of storage, individual loaves of bread are sliced in half-inch slices using an Oliver Slicing Machine (No. 777). The middle five slices are used for testing on the Instron 1 and the end slices are discarded. Three readings are taken on each of the five slices, one in the upper corner within one-half inch of the crust, another on the center of the slice, and a third in the opposite bottom corner about inch from thebottom-I The slices are then observed for crumb, grain, texture, color, and other visible characteristics. In determining the Instron values, the three readings per slice are averaged and the values of the five slices are averaged to give a specific number for the softness on that particular day for that particular loaf. If more than one loaf is used, an average for the number of loaves is taken to calculate the softness for the baking at that particular day. A softness index using the softness of the control bread as 1.00 is calculated. by dividing the Instron reading of the experimental sample by the reading of the control sample.
Table I gives the results of softness index for bread prepared using the emulsifier blend of the instant invention. The volume increase, a measure of conditioning, of each baking as compared to the control bread is also given.
1 Instron Model TM Standard Speed. Compression Load Cell No. CB Full Scale Load 1000 grams. compressibility distance4 mm. (0.16 inches). Compression plugger dlse1- inch diameter. Cross head speed-5 inches per nute. Chart speed20 inches per minute.
TABLE L-EXAMILES 9 T 13 BAKING RESULTS 1. A temperature-stable, clear liquid emulsifier composition consisting essentially of from to 90- weight percent of fatty acid monoesters of propylene glycol, from 0 to 85 weight percent of monoglyceride, and from 10 to 80 weight percent of a polyoxyethylene-containing compound selected from the group consisting of polyoxyethylenated fatty acid esters of glycerol, hexitan, hexitol, and isohexide, and fatty acid esters of a polyoxyethylenated glycerol, hexitan, hexitol, and isohexide, wherein said fatty acid monoesters of propylene glycol are at least 35% by weight alpha monoester and contain no more than by weight of the di-fatty acid ester of propylene glycol, and wherein said fatty acid moiety in said monoesters has 12-22 carbon atoms and are at least 60 mol percent unsaturated, said monoglyceride contains at least 86 mol percent of unsaturated fatty acid moiety, and where the mol ratio of ethylene oxide per mol of glycerol, hexitan, hexitol, and isohexide is said polyoxyethylenated compound is from about 4 to 1 through about 40 to 1, and said fatty acid moiety in said polyoxyethylenated compound has 12-22 carbon atoms.
2. A temperature-stable, clear liquid emulsifier composition according to claim 1 wherein the propylene glycol fatty acid monoesters comprise propylene glycol monooleate, and the polyoxyethylene-containing compound is selected from the group consisting of a polyoxyethylene fatty acid ester of sorbitol, sorbitan, and isosorbide, and a fatty acid ester of polyoxyethylene sorbitan, sorbitol, and isosorbide.
3. A temperature-stable, clear liquid emulsifier composition according to claim 1 wherein said mols of ethylene oxide per mol of hexitan, hexitol, and isohexide in said polyoxyethylene-containing compound is from about 8 10 to 1 to 20 to 1, the percent of unsaturated fatty acid moieties in said propylene glycol monoester is 85% and the weight percent of unsaturated fatty acid moiety in said monoglyceride is at least 86 mol percent of the fatty acid moieties present.
4. A temperature-stable, clear liquid emulsifier composition acoording to claim 3 wherein the hexitan, hexitol, and isohexide of said polyoxyethylene-containing compound is selected from the group consisting of sorbitol, sorbitan, and isosorbide.
5. A temperaturestable, clear liquid emulsifier composition according to claim 1 wherein the weight percent of each constituent are as follows: the polyoxyethylenecontaining compound from 35 to said monoglyceride from 30 to 40%, and said propylene glycol fatty acid ester from 20 to 30 weight percent propylene glycol monooleate.
6. A temperature-stable, clear liquid emulsifier composition according to claim 1 wherein the weight percent of said propylene glycol fatty acid ester is from about to and the weight percent of said polyoxyethylenecontaining compound is from 35 to 45 weight percent of the composition.
7. A temperature-stable, clear liquid emulsifier composition according to claim 5 wherein said polyoxyethylcue-containing compound is selected from the hexitol, hexitan, and isohexide compounds selected from the group consisting of sorbitol, sorbitan and isosorbide.
8. A temperature-stable, clear liquid emulsifier composition according to claim 6 wherein said polyoxyethylelse-containing compounds are selected from the group consisting of polyoxyethylene sorbitol, sorbitan, and iso sorbide.
References Cited UNITED STATES PATENTS 3,253,992 5/1966 Brooks 252356 X 2,269,529 1/ 1942 Goldsmith 252356 X 2,380,166 7/1945 Grifiin 252356 X 3,702,307 11/1972 Norris 252356 RICHARD D. LOVERING, Primary Examiner US. Cl. X.'R.
45 99-91; 252DIG. 1, DIG. 14