US2992923A - Methods for oxidatively ireating flour - Google Patents

Description

y 1961 c. G.'FERRARI ET AL 2,992,923

METHODS FOR OXIDATIVELY TREATING FLOUR Filed June 25, 1959 3 50 a 40 "flip/M, 4 Q E Q .30 ii u 20 s g /0 kl /2.4 .66 7'69/0///2 F/G. W5 W FIG. 2 77/145 (Om/5) INVENTORS CHARLES G. F 52/242! KAzuo H/GASH/UcH/ ATTORNEY United States Patent C) r 2,992,923 METHODS FOR 'OXIDATIVELY TREATING FLOUR Charles G. Ferrari, Evanston, and Kazuo Higashiuchi,

Chicago, 111., assignors to J. R. Short Milling Company, Chicago, 111., a corporation of Illinois Filed June 23, 1959, Ser. No. 822,225

8 'Claims. (Cl. 99-91) This invention relates to the treatment of cereal flours and particularly to an improved process for oxidatively treating flours to accomplish bleaching and/or maturing thereof.

Both maturing and bleaching of flours result from oxidative changes in the flour. Maturing can be considered as the same oxidative change which would result from natural aging of the flour .for a prolonged period, while bleaching results from the more or less complete oxidation of the carotinoid pigments of the flour to colorless reaction products. Numerous oxidizing agents have been proposed for maturing and bleaching flours. Of these prior art agents, most have been useful to accomplish only maturing or only bleaching. Thus, the bromates, the iodates and the persulfates, all accepted maturing agents, have no bleaching power. Conversely, benzoyl peroxide, one of the more commonly accepted bleaching agents, has no maturing power. The only known agent accepted for 2 bleaching and maturing action than do the reaction product mixtures as a whole.

The present invention is based upon the discovery that reaction product mixtures derived from methyl ethyl ketone and hydrogen peroxide are markedly superior to any of the aforementioned peroxidic acetone and hydrogen peroxide.

The flour-treating method of the present invention employs oxidatively active materials obtained by combining methyl ethyl ketone, hydrogen peroxide and water in proportions providing in the initial reaction mixture from .5 to 2.5 moles of hydrogen peroxide for each' mole of methyl ethyl ketone and maintaining the resulting initially homogeneous reaction mixture at below 100 C. until, upon standing at normal temperatures, the reaction mixture separates into phases of difierent specific gravity, the phase of lower specific gravity predominantly comprising methyl ethyl ketone peroxide and free methyl ethyl ketone. Advantageously, an acid catalyst is employed i-n proportions up to 5% by weight of the reaction products derived from .mixture to accelerate formation of the peroxidic product desired. Depending upon the relative proportions of methyl ethyl ketone and hydrogen peroxide, the amount of water introduced into the reaction mixture with the hydrogen peroxide or otherwise, the temperature at which I the reaction mixture is maintained, and whether or not commercial use and capable of both maturing and bleaching flours is chlorine dioxide. Chlorine dioxide has, how ever, proved to be disadvantageous'in several respects, the primary disadvantage being that it is too potent, so that an unduly critical control of the amount used must the reaction mixture is agitated, the reaction time can be selected within the range of from 1 minute to 48 hours.

Though the yield of methyl ethyl ketone peroxides so obtained is sufliciently high to allow use of the: entire re- Iiaction product mixture as a novel oxidatively active combe maintained to avoid over-treatment and damage to color and baking quality of the flour.

The present invention employs a single composition 1 capable of both maturing and bleaching flours, and, in

certain embodiments, the invention is adapted to accom- The invention has a number of' plish maturing alone.

important advantages in additionto such flexibility of f result. vention does not require such-precise control .of .the amount of oxidatively active material as has been neces- One primary advantage is the fact that the in- 1 position for bleaching and maturing flour, in which case water need not be employed, the reaction product mixtures obtained as above described are admirably suited to concentration in various Ways. First, the phase of 3 .lower specific gravity, amounting to as much as 80% by volume of the total reaction product mixture, is easily recoverable from the higher specific gravity material, only a small proportion of the oxidatively active products remaining in the higher specific gravity material.

both the free water and the free methyl ethyl ketone sary with chlorine dioxide. Thus, our invention makes 1: possible the successful treatment of flour withoutdanger of damaging the flour by overtreatment. A further major i advantage of our invention is its ability to gently treat flours in a manner which may be characterized as :ac.

celerated natural aging. Another distinct'advantage of; the present method is that it employs no materials which)? are deleterious to humanbeings. Further,.the invention :1

is particularly advantageousin that it makes possible the 1 adequatetreatment of flour with only a. very minimum 1:

of residual chemical agents in the flourafter treatment. In this connection, all embodiments of the invention involve at most the addition of only insignificant proportions ofnon-food materials capable of surviving baking,

, and certain embodiments of the invention make it poss1-';

ble to treat the flour in such a manner that there willbe no residue whatsoever of treating agent after baking.

In copending application Serial No. 15,783, filed concurrently herewith on behalf of Herbert O. Renner, there is disclosed a method for oxidatively treating cereal flours with certain reaction product mixtures derived from acepresent in the phase of lower specific gravity can be removed easily without undue loss of the desired peroxidic reaction products. Finally, a highly desirable flour bleaching and maturing product consisting essentially of i a single acyclic methyl ethyl ketone peroxide is obtainable from the phase of lower specific gravity by extraction with a low boiling hydrocarbon solvent such as hexane or pentane.

Advantageously, the oxidatively active materials derived'in the above manner from methyl ethyl ketone and hydrogen peroxide are combined with a carrier material, which can be either a finely particulate solid or a liquid. Where the carrier material is a finelyparticulatesolid;

theoxidatively active liquid reaction product mixture Y can ibe combined withthe solid in such proportions that'the liquid amounts to as much as 25% by weightof the combined liquid and carrier. 7 p a As has been pointedout, the phase of lower specific gravity resulting from reaction of methyl ethyl ketone 1 ;and hydrogen peroxide in the manner described contains,

tone and hydrogen peroxide, and with bis-(1,1" hydro- T peroxy 1,1'-met hyl) 'diethyl peroxide, a major constituent of such reaction product mixtures. Copending applica tion Serial No. 822,235, filed concurrently herewith by Kazuo Higashiuchi, discloses that the aqueous residuere maining after extraction .of such'reaction product mixe tures with low boiling'hydrocarbon solvents, for. example, 1 constitutes a superior composition for oxidativelytreating .l

flour, such aqueous residues having a materiallygreater in addition to methyl ethyl ketone peroxide, a substantial proportion of unreacted methyl ethyl ketone; Thus,

about 20-40% by weight of the phase of lower specific gravity may be free methyl ethyl ketone. Advantageously, this free ketone is left in the liquid material until after W the same has been combined with the carrierand is then at least largely removed by volatilization. Thus, employing a particulate solid material as the carrier, the free ketone can be removed by aerating the product, with 1 or without the aid of reduced pressure, at a temperature not exceeding C. Assuming that a relatively large Patented July' 18, 1961 Next,

proportion of the oxidatively active liquid reaction product mixture is combined with a solid carrier. material such as a cereal flour, especially good results are obtained by aerating with the aid of vacuum at a temperature of iO- SO, C. Ingeneral, the temperatures employed during removal of the free methyl ethyl ketone can be increased if (1) the proportion of methyl ethyl ketone peroxides introduced to the carrier material is relatively small or (2) the product introduced to the carrier material contains, only small proportions of materials other than acyclic methyl ethyl ketone peroxides and free ketone.

While efiective flour-treating compositions can be prepared from initial reaction mixtures in which the proportion of hydrogen peroxide ranges from .5 to. 25 moles per mole of methyl ethyl ketone, superior results are obtainedjwhen the proportion of hydrogen peroxide ranges from 1 to 1.5 moles per mole of ketone. Such proportions provide improved reaction rates and greater yields of methyl ethyl ketone peroxides. Within the limits specified, increasing the relative proportion of methyl ethyl ketonewill increase the volume of the lower specific gravity-material, also increasing the proportion of free ketone therein, while an increase in the relative proportion of hydrogen peroxide will increase the volume of the higher specific gravity product, also increasing the proportion of free hydrogen peroxide therein.

The rate of reaction and the yield of peroxides also depends upon the concentration of hydrogen peroxide in the initial reaction mixture. In this connection, the hydrogen peroxide is preferably employed in the form of an aqueous solution containing, at least 25% by. volume. hydrogen peroxide, and considerablewater is thus introduced into the reaction mixture; While the presence ofwater is not. essential to the. reaction, it. is required in order thatthe reaction, productmixturewill separate into phases of, lower. and higher specific gravity, thephase of highenspecific gravity retaining those? compounds which are. more soluble in Water. In order to. obtainthe advantages ofphase separation and still maintain good reaction ratesand yields, the proportion of water in the initial reaction mixture, whetheriadded with the hydrogen" peroxide or otherwise, is kept in the range of 10-50%. by volume, based. on thegtotal reaction mixture. Thus, an aqueous hydrogen peroxide solution should not beused which is so dilute as to provide, for the particular proportion oi hydrogen peroxide chosen, an amount of waterlin excess'of' 50% of the voliime of the initial reaction mixture. waterless than 10%. ofthevolume1of the initial reaction mixture is provided by addition of the hydrogen peroxide 1 solution, additionaliwater should be added to provide the minimum amount necessary for phase separation.

Thefreaction is.ratheistrongly exothermic. initially. However, if .thereaction mixture is cooled for an initial period. sufiicientto. remove the exothermic'heat, cooling canthenbe terminatedandthe reaction mixture will' remain cool forit-hebalance offthe reaction'period.

Best-yields of methyl ethyl k'etone peroxidesare obtained in the shortest reaction time when the reaction mixture is maintained at.aitemperature within the range of l5-70 C. Within such temperature range, and with the proportion of hydrogen peroxide being from 1 to 1.5 moles per mole of methyl ethyl ketone, the other process variables being controlled as hereinb efore discussed, the phase of. lower specific gravity will amount to fror'n' 35-80% by.volume. of the reaction productmixture', as

much as 8.0%. by weight of such lower .specijfie gravity phasebeing methyl ethylketone peroxides, the predomii' nantportion of the organic peroxide content being an individual. acyclic methyl ethyl ketone peroxide as "yet not completely characterized.

While the reaction proceeds at temperatures up to 100 C., the yield of the desired peroxides obtained ,in'aigiven reaction time decreases: as" the temperature is raisedabpve;

On the other hand, if an amount of about C. The reaction rate is also decreased when the, temperature of. the reaction mixture is decreased below 15 C. but, by extending the reaction time, good yields can be obtained at temperatures on the order of 10 C. and lower.

Excellent e ult r ob aine by om in n the e,

While other acid catalysts can be employed, best results:

have been obtained with the. mineral acids in. amounts up to about 5% by Weight of the reaction mixture. Among the. mineral acids, the ability of the. acid to catalyze the reaction varies between the individual acids. Thus, while excellent reaction rates and yields are attained by using 0.04-1% by weight of hydrochloric or sulfuric acid, the equivalent results are achieved with 0.4.4 of phosphoric acid. Practical reaction times on the, order. of 1v minute. are provided when 1% of hydrochloric or sulfuric acidis employed and when 4.% ofi phosphoric acid is employed. Without catalyst, the reactiontime can be extended to 48 hours.

Solid, particulate, edible carriers which are suitable for preparing. compositions useful in accordance with the invention includefood starches, particularly corn starch, dextrines, wheat flour, defatted wheat flour, heat-treated Wheat-,fiour, pre-oxidized starches and flours, vegetable proteins, such. as wheat glutenand soybean protein, and edible. inorganic. materials, such as inorganic phosphates and calcium sulphate, which are inertto peroxides. The particulate carrier material should provide a porousstructure or. a large. eifective surfacearea so that the oxidatively active liquid can be-retained by absorption and/or. adsorption.

In. treating the flour, the compositions prepared in accordance with, the procedure hereinbefore" describedcan beIsprayed as liquids directly into the flour while are used and the carrier-supported composition isordinarilyleft in the Hour after the oxidative treatment is completed. Therelative proportion of the oxidatively active compositions employed in accordance with the invention depends upon whether only maturing, or both maturing and bleaching, isdesired and also upon the extent to which maturing or bleaching and maturing are to be. accomplished. Ordina ly, the amount of-oxidatively active-methyl ethyl ketone peroxide composition employed is such as to provide a hydrogenproxide obtainingmildmaturing of the flour, the hydrogen per oxideequivalent valueiean be less than 0.001%by weight, Assuming that no additional oxidative agents .areemployed,bleaching can beaccomplished with quan tities of-theimethyl ethyl-ketone peroxide composition providing hydrogen peroxide equivalent values in the generalrange of 0;002%- to 0.006% or higher, depending uponttheirat'ureof the. flour-being treated. N

E AMBLB -An initially. homogeneous. liquid reactionmixture wasprepared by blending. 25 mLaqueous hydrogen peroxide.

mint (3Z ;H2O2.b1. z n e), 50 lmethyl e y ketone nc l -llllj concentrated sulfurieiacid. The:

t"? mat m ma e ub an ia y zit-mom; J tihe nd 1 whi b m he. a a e? Pret nd an ayers recove ed and the pro rtionof.

1 a, min tes. The

resulting liquid product wastreed' of water by means of anhydroussodium'sulfate. By titration; theresulting product was found to have a hydrogen peroxideequiva-- lent content of 32.6% by weight:

A.carrier-supported composition suitable for bleaching flour was prepared by blending 40 ml. of the liquid product so obtained with 100 g. of dry, food grade corn starch and drying the mixture at room temperature under an exhaust hood for 30 minutes. The carrier-supported composition, hereinafter referred. to as composition A, wasfound tovhave ahydrogen peroxide equivalent content of 4.9% by weight. 1

To determine the relative effectiveness of the bleaching andrnaturing composition of this example, acontrol composition wasprepared, in accordance with the aforementioned application Serial No. 15,783, by blending equi-molar proportions of acetone and aqueoushydrogen peroxide (60% by volume) and refluxing the. resulting liquid reaction mixture over awater bath for one. hour, the resulting reaction product mixture being v intimately combined with food grade-corn SIHIClTfiS B."

carrier material. The control composition is hereinafter referred to as composition B.

1 Equal quantities of a commercially available; un-

bleached bread wheat flour were measured out, one quan-' tity; beingcombined with a sufficient proportion of .compo-- sition A to incorporate in the flour a hydrogen peroxide equivalent of 0.0045% by weight and theother quantity of flour being combined with a sufiicient proportion ofcompositionUBto incorporate inthe flour the same hydrogen peroxide equivalent. The two quantities of flour were 'then'allowed to stand at room temperature in closed containersand the carotene content of the flour was measuredperiodically. The relative bleaching abilities- Of compositions A and B are plotted in the chart of FIG. 1,-.wherein it will be noted that composition Aof this example is, at two days, approximately 100% more effective as a bleaching agent than is control compositionaB.

EXAMPLE 2 An initiallyhomogeneous liquid reactionmixture was. prepared by blending 57ml. of aqueous hydrogen peroxide Solution (60% H by volume), 8915' ml. of

nietliyl etliyl'ketone and 5 ml. of 1 Nhydrochloric acid. Thereaction mixture was maintained substantially tat Iodin temperature fora period of 30 minutes, being agitated continuously during that period by means of aivibratingmagnetic stirrer. The resulting liquid was neutralized-byaddition ofS ml. of 1 N sodiumhydroxide and was then allowed to stand until ithad separated into distinct upper and lower phases; The upperphase was recoveredby means of a separatory funnel.

Of the*recovered liquid, 50 ml. was extracted with 500 of hexane, extraction being carried out at room temperature withcontinual agitation for 30 minutes and tlie heXane then removed under vacuum, leaving as the residue a viscous liquid product.

A carrier-supported composition suitable for" use .in bleaching flour and the like was preparedby blending 2 g; of tlre'viscous liquid product with g. of dry, food grade corn starch andaspirating the resultingblend for 30 minutes atroom temperature with air to remove any remaining traces of hexane or other volatiles. The resulting-product was found to have a hydrogen peroxide equivalent content of 4.35 by weight, and is hereinafter referred to as composition C.

For purposes of comparison, a control composition was prepareddn accordance with the aforementioned copendiiig-application Serial No. 15,783 by blendingequimolar proportions of acetone and aqueous hydrogen per:

oxide (60% H 0 by volume) and aging over a boil ing water batlr for one hour, the resulting reaction prodi uct rtiixture then beinggextracted five times with equal volumes of hexane, the extracts combined and thesol 'removed to provide a composition predominantly compfisingbis'-:(l;l -hydroperoxy 1,1'-methy1) diethyl perr oxide." 1 The product wasintiinately combinedwith food, grade corn starch, the resulting icomposition being herein after refeiredto"ascomposition D.

Equali samples of a commercially" available unbleached bread wheat flour'were measured out. A suflicient-prm portion of composition. C was added toone sample to incorporate therein a hydrogen peroxide equivalent contentof .006%' by weight; Similarly, a sufiicient proportion of composition D was blended with the other sample of flour to introduce-therein the samehydrogen peroxide equivalent. Thetwo samples-of flour were then allowed to i stand at room temperature in closed containers and: the carotene "content ofthe two samples was determined.

from time totirne; the results beingillustrated in FIG: 2. Here, it will be" noted thatcomposition C is vastly. su perior to composition D, providing adequatebleaching,

for commercial purposes, within a period of approximate ly two days.

In considering Examples l and 2, it; is tobe understood that these examples compare the' compositions of the present invention with the corresponding compositions ofapplicationSerial No. 15,783, which application discloses theonly other known oxidative agents, aside from:

chlorine dioxide, which are capable ofboth maturing and; bleaching wheat tflour. In Example 1, the comparison is between compositions whichare prepared by using sub-.- stantially the entire reaction product mixture, while the comparison in Example 2 is between products each predominantly comprising only a single peroxidic compound. In the case of composition D of Example 2,1the:

single compound is bis-(1,1'-hydroperoxy 1,.1'-methyl) diet-hyl peroxide. In the case of composition C of Example 2, the peroxidic compound of methyl ethyl. ketone';

has not asyet beencompletely characterized.

EXAMPLE 3 To demonstrate the effect of treatment of flour in accordance with the invention on bread baked. from. the flour, flour samples of a commercially available unbleached bread wheat flour were taken, sample 1 being.

used as control with no bleaching or maturing agent added thereto, and samples 2, 3 and 4 being treated by addition of composition A of'Example 1 in proportions providing in the fioursampleshydrogen peroxide equivalent values of .003,;0045 and.006% by weight, respeo tively. The flour samples were allowed'to stand 'inclosed containers for. 15 days at room temperature and white bread was tlien made by preparingseparate do-ughs from l each'flour sample by a conventional sponge-dough pro cedure, using. the following formula:

Sponge Ingredient; Dough;

Baked under identical conditions, the bread. from the four flour samples scored as follows:

It is thus apparent thatthe internal-characteristics of bread prepared from flour treated in accordance with the invention improved proportionately as the level of treatmentinc'reased from .003% by weight of the flour to .006%. The improvement in crumb color is that which would be. expected to result from bleaching of the magnitude described with reference to Example 1. The-improvement in loaf volume and grain is that which would be expected to result from adequate maturing of ,th flour.

Analytical procedures Total peroxide content of the reaction products preparedas hereinbefore described can be determined by (1) potassium iodide-thiosulfate titration, using aqueous sulfuric acid (1 part H 80 to 9 parts water by volume) or (2) modified Wheeler titration, omitting chloroform. The results are expressed as the hydrogen peroxide equivalent value.

Free hydrogen peroxide is determined as follows:

Step l.--A 0.05 g. sample of the material to be analyzed is combined with 25 ml. water and 1 mg. catalase and allowed to react for 30 min. Step 2.25 ml. aque ous sulfuric acid (1 part conc. H 80 to 4 parts water by volume) is added, followed by 1 ml. saturated potassium iodide solution. Step 3.The solution is titrated with standard thiosulfate to give the total organic peroxide content, free hydrogen peroxide having been destroyed by the catalase in step 1. Step 4.-Subtract the total organic peroxide content, determined in step 3, from the totalpenoxide content, the difference being free hydrogen peroxide.

Free methyl ethyl ketone is measured as follows:

Step 1 .Combine 200 ml. of .3% fresh hydroxylamine hydrochloride and a .2 g. sample of the material to be analyzed and allow to stand for 3 min. Step 2.-Titrate with standard .1 N sodium hydroxide until the pH is brought to the original pH of the hydroxylamine hydrochloride solution. Step 3.Compute percent free methyl ethyl ketone as follows:

(Titration value) (0.00777) 100) Sample weight =percent methyl ethyl ketone Characterization of methyl ethyl ketone peroxide constituting predominant proportion of reaction product The compound titrates in the same fashion as bis-(1,1'- hydroperoxy l,1-methyl) diethyl peroxide, the correspondingcompound derived from acetone.

Active oxygen was determined for the methyl ethyl ketone peroxide in question in the following manner: The phase of lower specific gravity produced in accordance with Example 1 was recovered and extracted with hexane, the solvent and free ketone then being removed from the extract by fractional distillation under vacuum. The residue from the distillation step was then dissolved in cold hexane, dried with anhydrous sodium sulfate and cooled to 70 C. on a Dry Ice-ethyl alcohol bath, causing the peroxide to be thrown down as a heavy, oily liquid. The hexane was decanted, the purified product recovered, and the procedure repeated. The active oxygen content of the finally recovered, purified product was 8 determined by titration with .1 N thiosulfate and computed in accordance with the following formula:

(Titration value) (.0008) Sample Weight =Peroent active 0 by weight;

The active oxygen was found to be 22.4% by weight,

.2% less than the theoretical active oxygen content of bis-(1,l'-hydroperoxy 1,l-ethyl) diethyl peroxide.

In similar determinations, the material thrown down from the cold hexane solution has varied from a solid to a heavy liquid at room temperature, apparently due to the presence of varying, small amounts of impurities.

Both the active oxygen determination and the fact that the corresponding cyclic compounds are not titratable by the thiosulfate procedure indicate that the product is the acyclic dimen'c peroxide of methyl ethyl ketone.

We claim: H 1. The method for oxidatively treating flour to material having a substantial peroxide content predominantly constituted by acyclic peroxidic reaction productsof methyl ethyl ketone and hydrogen peroxide which are titratable with thiosulfate, the proportion of said material employed providing a hydrogen peroxide equivalent value, based on the weight of the flour, of at least about 0.001%

2. The method for oxidatively treating flourf to at least mature the same comprising introducing into the flour a small but effective proportion of an oxidatively active liquid reaction product mixture, obtained by reacting methyl ethyl ketone and hydrogen peroxide at below 100 C., said reaction product mixture having a substantial peroxide content predominantly constituted by acyclic methyl ethyl ketone peroxide, the proportion of said reaction product mixture employed providing a hydrogen peroxide equivalent value, based on the weight of the flour, of at least about 0.001%.

3. The method of claim 2 wherein said liquid reaction product mixture is supported on a particulate carrier. 4. The method of claim 3 wherein said carrier is a finely particulate cereal product.

5. The method for oxidatively treating flour to at least,

mature the same comprising introducing into the floura small but eifective proportion of an oxidatively active material prepared by 1) combining methyl ethyl ketone, aqueous hydrogen peroxide and 0-5% of an acid catalyst to provide an initially homogeneous liquid reaction mixture containing 1050% by volume water and 5-2.5 moles of hydrogen peroxide per mole of methyl ethyl ketone, (2) maintaining such reaction mixture below 100 C. for from 1 minute to 48 hours and thereby causing the methyl ethyl ketone and hydrogen peroxide to react to form an acyclic methyl ethyl ketone peroxide, (3) allowing the resulting liquid reaction product mixture to separate into phases of lower and higher specific gravity;

mature the same comprising introducing into the flour a small but effective proportion of the acyclic peroxidic compound produced by (1) combining methyl ethyl ketone, aqueous hydrogen peroxide and '05% of an acid catalyst to provide an initially homogeneous liquid reaction mixture containing 10-50% by volume water and- .5-2.5 moles of hydrogen peroxide per mole of methylethyl ketone, (2) maintaining such reaction mixture ;be:

at lease mature the same comprising introducing into the flourj a small but effective proportion of an oxidatively active low 100 C. for from 1 minute to 48 hours and thereby causing the methyl ethyl ketone and hydrogen peroxide to react to form an acyclic methyl ethyl ketone peroxide, (3) allowing the resulting liquid reaction product mixture to separate into a phase of lower specific gravity, containing said methyl ethyl ketone peroxide in solution, and a phase of higher specific gravity, (4) recovering said phase of lower specific gravity, and (5) extracting said methyl ethyl ketone peroxide from said recovered phase, the proportion of said acyclic peroxidic compound employed providing a hydrogen peroxide equivalent value, based on the weight of the flour, of at least about 0.001%.

8. The method for oxidatively treating flour to at least mature the same comprising introducing into the flour a small but effective proportion of an oxidatively active material wherein at least a material proportion of the oxidatively active content is constituted by an acyclic References Cited in the file of this patent UNITED STATES PATENTS 1,483,546 Gelissen Feb. 12, 1924 1,539,701 Sutherland May 26, 1925 1,866,412 Van der Lee July 5, 1932 2,903,361 Marks Sept. 8, 1959 FOREIGN PATENTS 444,544 Great Britain Mar. 23, 1936

Claims (1)

1. THE METHOD FOR OXIDATIVELY TREATING FLOUR TO AT LEAST MATURE THE SAME COMPRISING INTRODUCING INTO THE FLOUR A SMALL BUT EFFECTIVE PROPORTION OF AN OXIDATIVELY ACTIVE MATERIAL HAVING A SUBSTANTIAL PEROXIDE CONTENT PREDOMINANTLY CONSTITUED BY ACYCLIC PEROXIDIC REACTION PRODUCTS OF METHYL ETHYL KETONE AND HYDROGEN PEROXIDE WHICH ARE TITRATABLE WITH THIOSULFATE, THE PROPORTION OF SAID MATERIAL EMPLOYED PROVIDING A HYDROGEN PEROXIDE EQUIVALENT VALUE, BASED ON THE WEIGHT OF THE FLOUR, OF AT LEAST ABOUT 0.001%.

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