Phosphates in Food

8/12/2019 Phosphates in Food

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PHOSPHATES Phosphates can have a large number ofdifferent functions in food products.

Salts of phosphoric acid may be either acidicor basic and therefore make excellent buffers.Solutions of poyphosphates have a high pH.Phosphates and polyphosphates havenegative charges (may have multiplenegative charges) in solution and interact withcations and other positively charged species(proteins, gums, etc).


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PHOSPHATES (multiple forms)

HOP

O

OH

OH

HOP

O

O-

OH

HO

P

O

O-

O-

-O

P

O

O-

O-


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PHOSPHATES (dehydration)

HO

P

O

OH

OH

+HO

P

O

OH

OH

- w ater

HO

P

O

O

OH

P

O

OH

OH


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Phosphates have multiple pKaspKa1~ 2.4pKa2~6.7Pka3 ~8.4In milk at pH 6.6

Monophosphate/phosphoric acid

43000/1Diphosphate/monophospaate 0.8/1Triphosphate/disphosphate 1/600000


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Phosphate Nomenclature1.Orthophosphate - Salts Of PhosphoricAcid Monobasic, Dibasic, Tribasic2.Polyphosphates - DehydrationProducts

A. Pyrophosphate - 2 P AtomsB. Tripolyphosphate - 3 P AtomsC. Sodiumhexametaphosphate - MixturesP>4


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Phosphates (GRAS, nutrient)182.5210 Calcium glycerophosphate182.5212 Calcium phosphate182.52213 Calcium pyrophosphate182.5301 Ferric phosphate182.5304 Ferric pyrophosphate182.5306 Ferric sodium pyrophosphate182.5434 Magnesium phosphate182.5455 Magnesium glycerophosphate182.5628 Potassium glycerophosphate182.8217 Calcium phosphate182.8223 Calcium pyrophosphate182.8458 Magnesium hypophosphite182.8778 Sodium phosphate


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Phosphates (GRAS)182.6085 Sodium acid phosphate182.6203 Calcium hexametaphosphate182.6215 Monobasic calcium phosphate182.6285 Dipotassium phosphate182.6290 Disodium phosphate182.6760 Sodium hexametaphosphate182.6769 Sodium metaphosphate

182.6778 Sodium phosphate182.6787 Sodium pyrophosphate182.6789 Tetrasodium pyrophosphate182.6810 Sodium pyrophosphate


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Phosphates (GRAS)182.1073 Phosphoric Acid182.1087 Sodium acid pyrophosphate

182.1217 Calcium phosphate (mono, di or tri basic)182.1778 Sodium phosphate (mono, di or tri basic)182.1781 Sodium aluminum phosphate182.1810 Sodium tripolyphosphate


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Orthophosphates (monomerPhosphate pH (!% soln) Solubility(g/100

Monosodium 4.4 48

Disodium 8.8 11Trisodium 11.8 13

Dicalcium 7.5 Insol

Tricalcium 7.2 Insol

Na Al acidic 2.4-2.5 Slight

Na Al basic 9.2-9.4 slight

Di potassium 8.8 63


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OrthophosphatesHelp to stabilize pH in foodsMono sodium phosphate (MSP) usedas an acidulateDi (DSP) and tri sodium (TSP)phosphate used to increase pHMSP and DSP combinations generallyused in buffering systems


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Pyrophosphates (Dimer)Phosphate pH (1% soln) Solubility (g/100)

Pyrophosphoric acid v. Acid Soluble

Calciumpyrophosphate

6.0 insoluble

Tetrasodiumpyrophosphate

10.2 61

Sodium ironpyrophosphate

70-7.2 insoluble


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TrimersPhosphate pH (1% solution) Solubility

Potassiumtripolyphosphate

9.8 65

Sodiumtripolyphosphate

9.8 13

Potassiummetaphosphates 4-8 (n=>400) insoluble

Sodiumtetraphosphate

7-8 (n =4-10 high


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Tripoly phosphatesPotassium tripolyphosphate

Only potassium polyphosphate is used in food

High costOnly used when others phosphates are tooastringent

Sodium tripoly phosphate

Only fully neutralized salt is usedUsed in limited amounts in foods


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Polymers of NaPO 3 (>3)

Sodium hexametaphosphate (n=5-15)PH 7.0, soluble

Sodium metaphosphate (n=50-100)pH 6.2, soluble


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Poly PhosphatesPolyphosphates often used to modifyprotein functionality. Two common onesin use are:

Quadraphos (n= 4 to 8) Hexametaphosphate(n=10-15)

Closer control of n provides better functionalityfrom batch to batch (11-13)(13-15)


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Phosphate FunctionsSequester metal ionsBufferIncrease water bindingAdjust pHAnti-caking agentForm ionic "bridges"Interact with proteins, other chargedhydrocolloids


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Phosphates found in many foods

most common are:Carbonated beveragesCereal products

Dairy productsEgg productsFruits and vegetables

Gums and gelsMeat productsPolyphosphates as microbial inhibitors


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Phosphates in carbonated beveragesMineral supplementation in some carbonatedand non carbonated beverages

Iron and calcium phosphates most common in non

carbonated beveragesComplex metal ions

Prevent loss of carbonation caused by heavy metals (25-90% less CO2 needed in untreated water

AcidificationCommon in cola beverages

Improve flow of powders in dry mixesTricalcium phosphate (TCP) most common in use and alsoassists in size distribution of the dry mix


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Phosphates In Cereal Products Leavening AgentsDecreased Cooking TimeBuffer pH in cereals during cooking

Dough Conditioners (SALP, acidic CPInhibition of enzyme activity (DSP)Antioxidant activity (MSP & DSP)CheaterMineral Enrichment

Color ImprovementImproved Tortillas by steeping corn in MSP,DSP or TSP(generally alkaline )Use of high molecular weight


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Phosphates as leavening agentsLargest use is in prepared mixesbecause of broad choice of phosphateswith different rates of CO 2 Salts of phosphoric acid and itspolymers used through neutralization to

form acidic salts


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Chemical LeaveningReaction between sodium bicarbonate andacidic phosphate salt

The phosphate will have at least tworeplaceable hydrogen atomsPhosphates provide

Acidification for release of CO2

Buffering to provide optimum pH for bakedproductInteraction with flour ingredients to provideoptimum viscosity and elasticity in the dough orbatter


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Factors affecting leavening actionProper selection of acidulationBubble size formed during mixingQuality of the gluten in the flour

Viscosity during mixingType of emulsification of the systemDough reaction rate (DRR) which combinesCO2 release during mixing and during benchaction (relaxation)Ratio of CO2 release during baking to thatduring dough preparation (varies widely)


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DRR for different phosphate

salts


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Evolution of CO 2 (%) 2 min. 8 min. During baking Mono Ca P 60 0 40 MCaP(coated) 15 35 50 Di Ca P 0 0 100

SALP 22 9 69 SAPP (slowest 22 11 67

SAPP (med.) 30 8 60


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Notes on most commonly used

phosphate leavening agentsMono calcium phosphate (MCP)

Most rapid release of CO2 complete during mixing used incombination with slower acting to retain CO2 release duringbaking

Anhydrous coated calcium phosphate (AMCP) cake mixes, selfrising doughDi-calcium phosphate (DCP)

Slowest release of CO2, generally all released during bakingSodium aluminum phosphates(SALP)

Bland flavors

Used in a wide range of bakery productsSodium acid pyrophosphates (SAPP)

AstringentOnly leavening agent usable for refrigerated doughCommonly used for cake doughnut mixes (or with MCP)


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Some combinationsCake mixesUse of highly emulsified shortenings, gives finer structureand reduces the amount of leavening agent needed

AMCP & SALP in white and yellow cakes

AMPC and SAPP or DCP in chocolate cakes, since CALP dullsthe chocolate color

Self rising flours AMCP because of stabilityBlends of AMCP SALP give better flavor and more stabilityin conditions of high humidity

Pancake mixesCombinations of MCP+SALP or MCP+SALP+SAPP to providestability during frozen storage. Freeze/thaw stability

Prepared Biscuit mixesBlends of 30-50% AMCP+50-70% SALP or SAPP


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Phosphates In Dairy Products Heat StabilityAge Gelation Stability

EmulsifyingChelation Of Fe & Cu In ButterMilk Gels (TSPP)Control Of Gum Gelation

Prevents Churning Of Ice CreamMelting Of Processed CheeseWhipping Aid


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Phosphates and the casein system of milkCasein exists in milk as micelles that arestabilizes by colloidal calcium phosphate

Calcium ortho phosphate is involved in theformation and stabilization of the caseinsystemMany of the applications in the processing ofdairy products involves interactions betweenphosphates and the casein or the calcium inthe micelles


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Heat stability salt balance (ratio of citrate & phosphate tocalcium and Magnesium) appears to controlheat stability of evaporated milk

Addition of ortho phosphate stabilizesconcentrated milk to retort sterilizationsUHT sterilization of concentrated milk givesdifferent results with phosphates. Agegelation is actually increased by the addition oforthophosphate and inhibited by polyphosphatesMechanisms are very complex and not fullyunderstood.


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Milk gels, Puddings & CheesecakeDry mixes are blended with milk, blended andrefrigerated to gelGelation is by the action of:

TSPP in the presence of calcium acetateMCP as the gelation acceleration with acetylatedmonoglyceridesCarrageenan in the presences of TSPP, STP or TSP withan additional calcium phosphate for puddingsInstant cheese cake also used TSPP and MCP. Milk isadded, poured into a graham cracker crust andrefrigerated ready to serve in 15 minutes


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Cheese applicationsProcessed cheese requires a calcium sequestering agentto remove calcium from the casein micelle of the cheesein order to emulsifiy the fat and turn the casein into athermal plastic materialIn addition, the citrates and/or phosphates provide abuffering capacity to stabilize the system in the pHrange of 5.4-5.6Blends of phosphates and citrates most commonly used,singly or in combination

Citrates predominate in products made with young cheesePhosphates predominate in products with aged cheese,SALP provides less flavor than DSPSince both young and aged cheeses used in most processedcheese and blend is used


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Egg productsProtect whole egg or egg yolk againstdiscoloration

Polyphosphates stabilize eggs against theaction of proteolytic enzymesSTP enhances the whipping properties ofegg whites.

SMP stabilized egg whites to pasteurization,with triacetin to prevent loss of foamingMSP reduced tendency for overbeating of eggwhites by reducing pH to 8.0


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Other Dairy (non cheese) ApplicationsIncrease solubility of nonfat dry milkIncrease whipping properties of caseinStabilize frozen desserts to fat agglomeration

Stabilize coffee whiteners during heat treatment andconcentration and prevent feathering type dependson other ingredients (DSP and KSP commonly used with the potassium salt giving less flavor and beingmore soluble; SALP used in some instances

Serve as buffers and stabilizing agents for protein filmsneeded to make a stiff foam (DSP, DKP, TSPP)


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Phosphates In Meat Products Stabilize Color

Polyphosphates (SMPH) provide pH 6.5-6.6 to retardoxidation of natural meat pigments that accelerate at the

normal ph of meat (5.2-6.0Increased Tenderness

Phosphates (SMPH, TSPP) cause dissociation ofactomyosin and improve tenderness of all meats.Action not associated with pHPyrophosphates combine with magnesium to givemuscle relaxation and improve tenderness


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Phosphates In Meat Products (cont)Enhance binding

Assist in extraction of actinomyosin andimproves binding used for reformed meat

Increases moisture retentionSMHP increases juicinessSHMP decreases cooking losses

Retard OxidationDSP most effectiveSTP, SHMP and SAPP +TSPP not effective

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Phosphates in Food