alkalizing cocoa and chocolate - blommer chocolate

The Manufacturing Confectioner • June 2015 31

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Throughout history no time period hashad a greater impact than the 19th cen-

tury on shaping the chocolate products oftoday. Rudolph Lindt developed the firstconche in 1879, which led to flavor improve-ment of chocolate. Daniel Peter was the firstperson to successfully incorporate milk intochocolate in 1876 after many others hadtried and failed. In 1847, Joseph Fry addedadditional cocoa butter into chocolate, giv-ing us the ability to form the chocolate barsof today. In order for Joseph Fry to haveaccess to cocoa butter, Casparus VanHouten developed and patented the cocoapress in 1828. Van Houten owned a factory in Nether-

lands which was producing cocoa drinks fromground cocoa beans. His chemist son, Coen-raad, recognized that further improvementscould be made to the cocoa. In 1828 he com-bined alkaline salts with cocoa powder, whichresulted in reduction of acidity (natural cocoais typically 5.0 –6.0 pH). This reduced bit-terness and sourness, making the drink morepalatable. It also improved the dispersibilityof cocoa powder in liquid. While the cocoabutter content was significantly reduced fromthe natural cocoa through pressing, its abil-ity to be incorporated into a drink still couldbe improved, and was, through neutraliza-tion. Color enhancement occurred as well.

Coenraad recognized the darkening of thecolor, giving it the appearance of a moreintense flavor. In general, the flavor wasenhanced through the smoothing out of thesour and bitter flavor undertones, creatingthe precursor for cocoa drinks today. Coenraad Van Houten patented his cocoa-

alkalizing discovery in Netherlands in 1828,hence the phrases dutched cocoa or alka-lized cocoa are now used synonymously intoday’s chocolate industry. Van Houten’spatent ran out after 10 years and now thecocoa and chocolate dutching method is usedextensively in the food industry. Alkalizedcocoa or chocolate can be found in drinks,ice cream and frozen treats, baked goods,pastry and compound coatings, as well asalkalized or dutched chocolates. Van Houten’s discovery is the basis for

this paper. Topics for discussion include alka-lizing cocoa and chocolate today, alkalizedchocolate and compound, as well as the appli-cation impact of alkalized cocoa.

THE ALKALIZING PROCESSX

The process of alkalization can be brokendown into three main categories: nib alka-lization, cocoa cake alkalization and choco-late liquor alkalization. Each process hasdistinct advantages and disadvantages.

Alkalizing Cocoa andChocolateMatching the proper alkalized cocoa or liquor to the properapplication is the key to a successful product.

Arlen MoserBlommer Chocolate Co.

Arlen Moser has 30years of experience inchocolate working forBlommer Chocolate.He began his careerin production andsupervising the qualitycontrol department.He progressed into hiscurrent position lead-ing research anddevelopment for theEast Coast operation.

Nib AlkalizationNib alkalization (Figure 1) is the prevalentalkalization method across the United Statesand Europe because it offers advantages incoloring and flavoring not present in theother methods. Deeper and more intensereds are possible while offering a clean flavor.The first step of nib alkalization is car-

ried out by fracturing raw cocoa beans thenremoving the shell or skin. The remainingproduct is the cocoa nib or meat of thecocoa bean. The nibs are then soaked in analkali solution with additional moistureadded, possibly as high as 50 percent. Thestrength of the solution is predeterminedby the desired pH and color of the endproduct as well as the starting pH of thecocoa beans used. This alkali solution isgiven time to penetrate and react with thecocoa nib. During this process, time andtemperature are controlled because longertime, higher temperature and basic pH con-ditions favor formation of more intensifiedcolor due to sugar degradation, Maillardreaction and anthocyanin polymerization. Aeration can be performed to further

enhance red notes through intensified oxi-dation of anthocyanins and other polyphe-nolic substances, either while under pres-sure or at normal atmosphere. Steam orair pressure could be added to hasten thedarkening or browning effects dependingon system capabilities or desired outcome.Vacuum is also an atmospheric mechanismused to manipulate color and enhancemoisture reduction.

Following the alkali reaction, roasting isrequired. Depending on the roasting systemand moisture content of the nib alkali mix,some drying may be required before enter-ing the roaster. Roasting will complete thedrying process while enhancing chocolateflavor. The time and temperature of the roastwill impact the final color and flavor in addi-tion to the alkali reaction time. When the alkali reaction and roasting are

complete, the nibs are ground into choco-late liquor. The particle size is reduced (usinga ball mill or stone mill), the liquor is pressedinto cocoa cake and cocoa butter fractions,then the cocoa cake is milled into a fine pow-der. The red or dark powder is now com-plete. It is also possible to eliminate the press-ing step and use the alkalized liquor directlyin chocolate.While flavor and color are positive attrib-

utes of nib alkalization, there are also somenegative aspects. Alkalizing the cocoa nibsalso alkalizes the cocoa butter. Cocoa but-ter processed with alkali can have increasedsoaps, which if excessive, can soften the cocoabutter and impact the tempering if choco-late is its final use. The cocoa butter flavorcan be altered and, depending on the degreeof alkalization, the cocoa butter color can beimpacted as well. This creates the need forpretreatment and deodorization of the cocoabutter, which results in yield loss. Becauseof this cocoa butter yield loss and expensiveequipment required, nib-alkalized cocoa istypically more costly than liquor-alkalizedcocoa or alkalized cocoa cake.

Alkalizing Cocoa and Chocolate

Nib alkalization isthe prevalent

alkalization methodacross the UnitedStates and Europebecause it offers

advantages incoloring andflavoring notpresent in the

other methods.

32 June 2015 • The Manufacturing Confectioner

➤Figure 1

Nib Alkalization

Cocoa Cake AlkalizationCake alkalization (Figure 2) is performedwith cocoa butter already pressed from thechocolate liquor, usually down to 10 to12 percent fat content. The roasting, win-nowing, nib grinding into chocolate liquorand pressing have already occurred whenthe cake alkalization takes place. Cake alkalization is typically performed

on kibble (gravel-sized pieces of cocoaground from press cake) in a reaction ves-sel. Similar to nib-alkalized cocoa, the pHof the natural cocoa will impact the fin-ished product. Also similar to nib alka-lization, an alkali solution is added, timeand temperature will continue to be fac-tors, and pressure and vacuum are alsobeing applied depending on the desiredoutcome. Aeration is applied as well invarying volumes to influence red notes inaddition to being used as a drying mecha-nism. The alkalized kibble will be dried to5 percent moisture or lower and thenmilled into a finished cocoa powder.A positive factor of cocoa cake alka-

lization is that only the cocoa is alkalized

and not the cocoa butter. Not having alka-lized cocoa butter as a byproduct makescake alkalization more economical andcould lead to a lower price. It also givesnonbean roasters the opportunity to pro-duce alkalized cocoa. Negative factorsinclude limitations in color developmentand impact to flavor; flavors may be lesspronounced or washed out as an already-roasted cocoa is being reprocessed. Addi-tionally, because kibbled cocoa cake isinconsistent in size, penetration of solu-tion to each particle will vary. Particle sizereduction in cake alkalization is also agreater challenge than other alkalizationmethods. Through the wetting and thendrying of the cocoa particles, agglomera-tion occurs, creating the need for higherenergy requirements for cocoa particlegrinding than nib or liquor alkalization.

Chocolate Liquor Alkalization

Chocolate liquor alkalization (Figure 3) issimilar to cake-alkalized cocoa. It occursafter roasting, winnowing and grinding intochocolate liquor. As with other methods,


A positive factor of cocoa cakealkalization is thefact that only thecocoa is alkalizedand not the cocoabutter.


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Figure 2

Cocoa Cake Alkalization

Figure 3

Chocolate Liquor Alkalization

the starting pH is a factor and an alkalisolution is required. Time and tempera-ture as well as atmospheric influencesaffect the final product. There are limita-tions to moisture addition. Water additionto chocolate liquor makes it more viscousand difficult to work with. Also, due to thedensity of the mass, aeration influences arelimited in their impact, creating less colorchange. After the alkali reaction, moistureremoval is needed. This can be assistedwith a thin film column evaporator andmay further enhance flavor development.Pressing of the liquor (if being used forcocoa) and milling of the cocoa are neededto complete the alkalized cocoa powder.A positive aspect of chocolate liquor

alkalization is that noncocoa-bean proces-sors are able to perform liquor alkaliza-tion and it can be performed with limitedequipment. The negative is that the cocoabutter is alkalized, similar to nib alkaliza-tion, resulting in further processing of thecocoa butter and additional expense. Thereare color limitations as well. Because ofthe density, and inability to use moisture athigh rates, deep reds are difficult to achieveand darker brown is usually the result.

Alkalizing IngredientsThe alkalizing ingredients shown in Fig-ure 4 can be used in alkalizing cacao. Thelimiting quantity is for each 100 parts ofcacao nibs; the total quantity of alkalizingingredients used is not greater in neutral-izing value than three parts by weight ofpotassium carbonate. Varying rates of these alkali ingredients

can be used to achieve the desired cocoa

product. Each will result in different fla-vors and functional attributes. Cocoa beans,nibs, liquor or cocoa cake treated withthese alkali ingredients will be accompa-nied by the statement Processed with alkalion an ingredient declaration label.

Processing Variables Impacting theFinished Product

There are multiple processing variablescapable of influencing the finished productbeyond the alkalizing agent used.

Cocoa bean origin The substrate of thealkalizing process has a major impact.Cocoa beans vary in flavor and colorthroughout the world and crop qualityvaries due to weather influences. Good flavor dutched cocoa or chocolate cannotbe derived from poor quality beans andcould be a product’s downfall before theprocess is started. Color of the cocoa beanis important for powders. If a finished prod-uct of deep red cocoa is desired, it cannotbe achieved unless some of the color isinherent in the bean.

pHThe pH impacts flavor and color. Thisincludes the starting pH of the beans(between 5.0 and 6.0) as well as the amountand type of alkali used. High pH is associ-ated with darker colors.

Time/temperatureReaction temperaturesfor red cocoas will typically be in the 75° to85°C range and browns and blacks will bein the 95° to 125°C range depending ondesired color and equipment capabilities.Holding cocoa at high temperatures forextended periods of time will influencecolor and flavor and if held too long willeventually damage the flavor.

MoistureThe amount of water used in thereaction can accelerate color formationand enhance red notes. Moisture between20 to 50 percent can be used if the processequipment is capable and the moisture inthe bean should be accounted for as well.High moisture will assist in achieving red


Good- flavordutched cocoa orchocolate cannotbe derived from

poor-quality beansand could be a

product’s downfallbefore the process

is started.


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CFR-Code of Federal Regulations Sec. 163.110-114 Potassium Sodium Ammonium Magnesium

Carbonate K2CO3 Na2CO3 (NH4)2CO3 MgCO3

Bicarbonate KHCO3 NaHCO3 NH4CO3

Hydroxide KOH NaOH NH4OHOxide MgO

Figure 4

Alkalizing Ingredients Used in Alkalizing Cacao

notes but it should be noted that the watermust be evaporated and may requireextended drying or roasting time, affect-ing the flavor.

Oxidation Air quality and quantity willaccelerate the alkalizing process. Aerationof the cocoa with high volumes of air foran extended period of time will enhancered notes.

AtmosphereAir pressure or steam pressurewill accelerate the browning of the cocoaand assists when producing black cocoa.Steam pressure can also be used to acceler-ate nib penetration with the alkali solution.It should be noted that excessive pressure oragitation may cause the cocoa butter to dif-fuse to the surface of the nibs, causing flowa-bility and manufacturing issues. Vacuum canbe used as a tool as well but is typically usedin the drying process.

ALKALIZED CHOCOLATE AND COCOACOMPOUNDXXXXXXXXXXXXXXXXXXX

According to Mintel Group there havebeen more than 100 new launches ofchocolate and compound products con-taining alkalized liquor or cocoa over thelast three years. This is in addition to manyof the fine alkalized chocolate productsalready on the market. Adding alkalized liquor into chocolate

can have positive influences on the finishedproduct. Nonalkalized chocolate liquor willbe more acidic and bitter while a dutchedliquor or cocoa properly alkalized to a neu-tral pH will have a less astringent taste pro-file. This gives a producer an opportunity toproduce more than one flavor from the samebean type. The dutched flavor may pair morefavorably with a shell-moulded or enrobedcenter, providing a superior flavor experi-ence. Alkalized liquor or cocoa as an ingre-dient in chocolate may also present the pro-ducer with the opportunity to reduceconching time because many of the volatileshave already been removed.Color of an alkalized chocolate is darker

when compared to an identical nonalka-lized formula. This presents some oppor-tunities. Boxed chocolates tend to displaymultiple, noticeably different dark choco-lates in the same box, differentiating eachpiece. The darker color may be a perfectapplication for the finished good. While itis less prevalent, alkalized liquor or cocoacan be used in milk chocolate as well.The liquor percentage of the chocolate

recipe can be completely alkalized oradded as a blend of alkalized and nonal-kalized chocolate liquor depending on theflavor desired. Additionally, alkalized cocoacan be added as an ingredient in choco-late to supply the dutched flavor.

Alkalized Cocoa in CompoundCoating

Cocoa compound coating is an alternativeto milk or dark chocolate and the addedcocoa powder is the main flavor-drivingingredient. Compound offers the advan-tage of a coating with multiple meltpointswhich can offer new product possibilities aswell as the ability to supply products inwarmer climates. The chocolate flavor isdriven by the type and quantity of the alka-lized and nonalkalized cocoa powder. Cocoa powder is the main color driver as

well. If strong cocoa flavor is not a require-ment for the finished product, there may beopportunities to use darker alkalized pow-der in a lower dosage to produce the samecolor. This can present a quality improve-ment and possible cost savings. While thecocoa butter has been pressed from theliquor, 10 to 12 percent cocoa butter stillremains in the cocoa. Cocoa butter in high-enough quantities paired with the addedlauric fat in compound will create a eutec-tic effect. This is good for softening achocolate center but is damaging to theshine and shelf life of a coating. Alkalizedliquor is a possible ingredient for a fillingor center but is not an ingredient for acompound coating for this reason.


Nonalkalizedchocolate liquorwill be more acidicand bitter while adutched liquor orcocoa properlyalkalized to aneutral pH willhave a lessastringent tasteprofile.


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APPLICATION IMPACT OF ALKALIZEDCOCOA POWDERXXXXXXXXXXXXXXXX

FDA description of cocoa powder is:

the food prepared by pulverizing the remain-ing material after part of the cacao fat hasbeen removed from ground cacao nibs.Optional alkali ingredients also specifiedand limited in CFR 163.110 (b) (1) maybe used in preparation of cocoa. Cocoapowder will be less than 24 percent fat,falling under the designations high-fat (break-fast cocoa), medium-fat (10 –22%) or low-fat cocoa (<10%) whether alkalized or non-alkalized.

Evaluating the ideal cocoa powder canbe a difficult task as the final result is notalways predictable. To evaluate cocoaimpact properly, putting the cocoa in anapplication is always necessary to exam-ine the cocoa’s true intrinsic color. Earlyindicators such as extrinsic color can bemisleading. For instance, 22 to 24 percentfat cocoa powder (breakfast cocoa) and a10 to 12 percent fat cocoa powder alka-lized to the same pH under the sameparameters will appear different. The 22 to24 percent powder will appear darker incolor, giving the impression of stronger fla-vor and greater coloring impact. This willnot be the case due to the fact that the10 to 12 percent powder will have morecocoa solids and greater flavoring and col-oring capability when used at the samerate. Other parameters such as moisturecontent and cocoa temperature can be mis-leading in extrinsic observation.

Cocoa DrinksCocoa drinks, whether hot or cold, oftencontain a lightly alkalized cocoa powder.The smoother taste with lowered bitternotes appears to appeal to the masses.Besides flavor and an attractive reddish-brown color, an alkalized cocoa offersgreater dispersibility over a nonalkalizedcocoa. However, while cocoa dispersion isgreater in the dutched cocoa, it is not com-pletely soluble. The cocoa will be initiallydispersed in a milk or water drink but will

allow for sediment to collect on the bot-tom of the container over time. The fatcontent is also a hindering factor in blend-ing cocoa into a water-based drink. Emul-sifiers such as lecithin are needed to reducethe surface tension between the fat-lovingand water-loving molecules. Thickeners,such as carrageenan, are used to help keepthe cocoa solids in suspension longer.

Desserts

Final impact prediction of alkalized cocoapowder on a dessert can be difficult as well.Type of dutched cocoa and the dosage usedare obvious factors influencing the final flavor and color of the dessert. But, theother ingredients play a role as well. Forinstance, the addition of a nonfat milk pow-der may have a lightening effect on thefinal product color as well as muting somecocoa notes. Conversely, the addition ofmore fat to the recipe in the form of but-ter and margarine could have a darkeningeffect. If heat treatment of the dessert isrequired, color and flavor will be impactedas well. Air content plays a role in the colorand flavor of a whipped or foam-formingdessert. Greater air content will lightencolor and reduce flavor impact. A greaterdosage of cocoa may be required to deliverthe chocolate impact desired.Ice cream is an ideal application for

alkalized cocoa and, behind vanilla, choco-late ice cream is the second-most popularflavor. Similar to whipped desserts, theincorporation of air affects color and flavorimpact. Chocolate ice cream with highoverrun will appear lighter compared tothe same recipe with reduced overrun. Anincreased dosage or a darker cocoa maybe required if high overrun is a require-ment to meet color standards. High over-run reduces cocoa flavor as well as the factthat ice cream is a frozen treat. Low tem-peratures desensitize the taste buds, cre-ating a need for higher flavor impact deliv-ered by a larger alkalized-cocoa dosage.


If strong cocoaflavor is not a

requirement for thefinished product,

there may beopportunities to

use darkeralkalized powder in a lower dosage

to produce thesame color.


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Nothing can be more disappointing thanlooking at a rich-appearing chocolate treat,biting into it and finding out that it doesn’tdeliver the expected flavor.

Baked GoodsChocolate cake and pastry are consumedand enjoyed worldwide. Cocoa powder istypically the flavor and color driver and,like whipped and cooked desserts, colorand flavor of the final product are difficultto predict. Experimentation on type ofcocoa and dosage used will be requiredwhen developing a new product to achievethe ideal visual and sensory experience.Any type and color of cocoa can be addedbut close attention should be paid to thepH of the cocoa used as well as the leav-ening agent. Natural cocoa is typically a5.6 pH but can range as low as 5.0 pH.Alkalized red cocoas are typically in the6.8 to 7.8 pH range, while black cocoaranges from 7.8 to 8.6 pH. A cake recipewith natural cocoa powder and possiblyother acidic ingredients, such as Greekyogurt, buttermilk or sour cream, willrequire baking soda as the leavening agentsince the baking soda is acid activated. Analkalized cocoa with a pH greater than 7.0will require baking powder for leaveningsince there is not sufficient acid to activatebaking soda. Proper experimentation withnew recipes should be performed as toolittle or too much leavening agent will havenegative implications on leavening (rise) orflavor (metallic or bitter).

Flavanol ImpactIt would be remiss not to discuss polyphe-nol and flavanol impact in this day and agesince the cocoa and chocolate industry isreceiving a substantial amount of positivepress for high polyphenol and flavanol con-tent. Polyphenols and one of its subgroups,flavanols, are known for antioxidant activ-ity and many health benefits includingimproved cardiovascular health, reducedoxidative effects of l d l cholesterol,

reduced blood pressure and many otherpotential improvements.Polyphenols refer to a broad class of

compounds found in all plants. Thepolyphenol category contains many sub-groups including flavonoids, which breakdown into many other subgroups includingflavanols, which in turn have subgroups oftheir own. For the purpose of this paper,the concentration will be on flavanols. It is widely suspected that alkalizing of

cocoa and chocolate will have negativeeffects on flavanol content. As discussedpreviously, there are many components toalkalization, including the extent to whichthe cocoa or chocolate is alkalized. TheHershey Center for Health and Nutritionperformed a flavanol-content study on 20commercial cocoa powders from seven dif-ferent companies. The cocoa powders var-ied in range from nonalkalized to moder-ately alkalized with the gauge being theextractable pH. The pH range was pH 5.39for the most acidic to pH 8.06 for the mostalkaline. The 20 commercial cocoas werearranged into four categories: nonalkalized,pH 5.39 to 5.76; lightly alkalized, pH 6.77 to7.13; moderately alkalized, pH 7.21 to 7.52;and heavily alkalized, pH 7.69 to 8.06. Thefat was extracted and testing was performedto establish total flavanol content.

Total Flavanols versus pH

As indicated by the chart in Figure 5, thetotal flavanol content had an inverse rela-tionship with the pH value. When the pHincreased, the flavanol content decreased.In the case of the heavily alkalized cocoa,it decreased substantially, but still had fla-vanol content remaining. Even thoughthere were losses, the average flavanol con-tent of the lightly alkalized cocoa 13.8(mg/g) and the medium-alkalized cocoa7.8 (mg/g) would still remain in the top10 percent of measured foods withdetectable flavanols in the USDA data-base. Alkalization appears to have a neg-


Nothing can bemore disappointingthan looking at arich-appearingchocolate treat,biting into it andfinding out that it doesn’t deliver theexpected flavor.


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Alkalizationappears to have anegative effect on

flavanols but cocoahealth benefits are

still significant.


ative effect on flavanols but cocoa healthbenefits are still significant.While this was a comprehensive study

of the relationship of pH and flavanols,many questions remain unanswered. Notmentioned in the study were alkalizingagent used, type of alkalization process(nib, cake, liquor), roasting times, bean ori-gin, fermentation levels, flavanol load priorto alkalization, etc. These and many otherfactors affect flavanol content in cocoa andchocolate beyond the alkalization process.

CONCLUSION

Alkalizing cocoa and chocolate has beenapplied and enjoyed for the past 187 years.Through the process, consumers have beenable to enjoy dutched chocolates with theirreduced bitter flavor and intensified color.Alkalized cocoa powders are now enjoyed inmany colors, with distinctly improved fla-vors and in some cases used where a naturalcocoa just wouldn’t be a good application.Compound coatings have been possible sincethe invention of the cocoa press, but the abil-ity to use alkalized cocoa greatly expandsthe color and flavor possibilities.Alkalized cocoa and chocolate liquor is

typically produced through three differ-ent methods: nib alkalization, cocoa cakealkalization and liquor alkalization. Theyhave advantages and disadvantages for thesuppliers and the users of these products.Nib alkalization offers the greatest rangeof color and usually the finest flavor, but it

comes at a higher cost of production andhigher cost to the consumer. Cake alka-lization is usually less complicated to pro-duce and has no impact on the cocoa but-ter, but it has color limitations as well asreduced flavor. Chocolate liquor alkaliza-tion requires less equipment to producebut has color limitations and can nega-tively affect the cocoa butter. Matchingthe proper alkalized cocoa or liquor to theproper application is the key to a success-ful product. n

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Beranbaum, Rose Levy, Maria Guarnaschelli,Vincent Lee, and Manuela Paul. Under-standing Cakes. The Cake Bible. New York:W. Morrow, 1988. Pp 473 –77. Print.

http://humantouchofchemistry.com/coenraad-johannes-van-houten-discovery-of-cocoa-powder.htm

http://exhibits.mannlib.cornell.edu/chocolate/houten.php

Li, Yue, Song Zhu, Yun Feng, Feifel Xu, JiangoMa, and Fang Zhong. Influence of Alkaliza-tion Treatment on Color Quality and TotalPhenolic and Anthocyanin Contents inCocoa Powder. Food Science and Biotech-nology 23.1: 59 –63, 2014.

Miller, Kenneth B., William J. Hurst, Mark J.Payne, David A. Stuart, Joan Apgar, Daniel S.Sweigart, and Boxin Ou. Impact of Alkaliza-tion on the Antioxidant and Flavanol Con-tent of Commercial Cocoa Powders” Journalof Agriculture and Food Chemistry 56th ser. J.Agric.Food Chem Pp8527 –533, 2008.

United States. Food and Drug Administration.Department of Human Health and Services.Code of Federal Regulations Title 21. Vol.Part 163., 2014. Print. Cacao Products.

Zijderveld, J. A. Cocoa Mass, Cocoa Butter, andCocoa Powder. Industrial Chocolate Manu-facture and Use. By E. H. Meursing. Thirded. London: Blackwell Science, 1999. Pp 101 –14. Print.

Figure 5 Hershey Center for Health and Nutrition

Total Flavanols versus pH

Presented at the PMCA Production Conference

alkalizing cocoa and chocolate - blommer chocolate

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