PHOSPHATESPhosphates can have a large number of different functions in food products. Salts of phosphoric acid may be either acidic or basic and therefore make excellent buffers. Solutions of poyphosphates have a high pH. Phosphates and polyphosphates have negative charges (may have multiple negative charges) in solution and interact with cations and other positively charged species (proteins, gums, etc).

PHOSPHATES (multiple forms)

PHOSPHATES (dehydration)

Phosphates have multiple pKaspKa1~ 2.4pKa2~6.7Pka3 ~8.4In milk at pH 6.6Monophosphate/phosphoric acid 43000/1Diphosphate/monophospaate 0.8/1Triphosphate/disphosphate 1/600000

Phosphate Nomenclature1.Orthophosphate - Salts Of Phosphoric Acid Monobasic, Dibasic, Tribasic2.Polyphosphates - Dehydration Products A. Pyrophosphate - 2 P AtomsB. Tripolyphosphate - 3 P AtomsC. Sodiumhexametaphosphate - Mixtures P>4

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

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 metaphosphate182.6778 Sodium phosphate182.6787 Sodium pyrophosphate182.6789 Tetrasodium pyrophosphate182.6810 Sodium pyrophosphate

Phosphates (GRAS)182.1073 Phosphoric Acid182.1087 Sodium acid pyrophosphate182.1217 Calcium phosphate (mono, di or tri basic)182.1778 Sodium phosphate (mono, di or tri basic)182.1781 Sodium aluminum phosphate182.1810 Sodium tripolyphosphate

Orthophosphates (monomer

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

Pyrophosphates (Dimer)

Trimers

Tripoly phosphatesPotassium tripolyphosphateOnly potassium polyphosphate is used in foodHigh costOnly used when others phosphates are too astringentSodium tripoly phosphateOnly fully neutralized salt is usedUsed in limited amounts in foods

Polymers of NaPO3 (>3)

Sodium hexametaphosphate (n=5-15)PH 7.0, solubleSodium metaphosphate (n=50-100)pH 6.2, soluble

Poly PhosphatesPolyphosphates often used to modify protein functionality. Two common ones in use are:Quadraphos (n= 4 to 8)Hexametaphosphate(n=10-15)Closer control of n provides better functionality from batch to batch (11-13)(13-15)

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

Phosphates found in many foods most common are:Carbonated beveragesCereal productsDairy productsEgg productsFruits and vegetablesGums and gelsMeat productsPolyphosphates as microbial inhibitors

Phosphates in carbonated beveragesMineral supplementation in some carbonated and non carbonated beveragesIron and calcium phosphates most common in non carbonated beveragesComplex metal ionsPrevent loss of carbonation caused by heavy metals (25-90% less CO2 needed in untreated waterAcidificationCommon in cola beveragesImprove flow of powders in dry mixesTricalcium phosphate (TCP) most common in use and also assists in size distribution of the dry mix

Phosphates In Cereal ProductsLeavening AgentsDecreased Cooking TimeBuffer pH in cereals during cookingDough Conditioners (SALP, acidic CP Inhibition 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

Phosphates as leavening agentsLargest use is in prepared mixes because of broad choice of phosphates with different rates of CO2Salts of phosphoric acid and its polymers used through neutralization to form acidic salts

Chemical LeaveningReaction between sodium bicarbonate and acidic phosphate saltThe phosphate will have at least two replaceable hydrogen atomsPhosphates provideAcidification for release of CO2Buffering to provide optimum pH for baked productInteraction with flour ingredients to provide optimum viscosity and elasticity in the dough or batter

Factors affecting leavening actionProper selection of acidulationBubble size formed during mixingQuality of the gluten in the flourViscosity during mixingType of emulsification of the systemDough reaction rate (DRR) which combines CO2 release during mixing and during bench action (relaxation)Ratio of CO2 release during baking to that during dough preparation (varies widely)

DRR for different phosphate salts

Evolution of CO2 (%)2 min.8 min.During bakingMono Ca P60040MCaP(coated)153550Di Ca P00100SALP22969SAPP (slowest221167SAPP (med.)30860SAPP (fast)40852

Notes on most commonly used phosphate leavening agentsMono calcium phosphate (MCP)Most rapid release of CO2 complete during mixing used in combination with slower acting to retain CO2 release during bakingAnhydrous coated calcium phosphate (AMCP) cake mixes, self rising doughDi-calcium phosphate (DCP)Slowest release of CO2, generally all released during bakingSodium aluminum phosphates(SALP)Bland flavorsUsed 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)

Some combinationsCake mixesUse of highly emulsified shortenings, gives finer structure and reduces the amount of leavening agent neededAMCP & SALP in white and yellow cakesAMPC and SAPP or DCP in chocolate cakes, since CALP dulls the chocolate colorSelf rising floursAMCP because of stabilityBlends of AMCP SALP give better flavor and more stability in conditions of high humidityPancake mixesCombinations of MCP+SALP or MCP+SALP+SAPP to provide stability during frozen storage. Freeze/thaw stabilityPrepared Biscuit mixesBlends of 30-50% AMCP+50-70% SALP or SAPP

Phosphates In Dairy ProductsHeat StabilityAge Gelation StabilityEmulsifyingChelation Of Fe & Cu In ButterMilk Gels (TSPP)Control Of Gum GelationPrevents Churning Of Ice CreamMelting Of Processed CheeseWhipping Aid

Phosphates and the casein system of milkCasein exists in milk as micelles that are stabilizes by colloidal calcium phosphateCalcium ortho phosphate is involved in the formation and stabilization of the casein systemMany of the applications in the processing of dairy products involves interactions between phosphates and the casein or the calcium in the micelles

Heat stabilitysalt balance (ratio of citrate & phosphate to calcium and Magnesium) appears to control heat stability of evaporated milkAddition of ortho phosphate stabilizes concentrated milk to retort sterilizationsUHT sterilization of concentrated milk gives different results with phosphates. Age gelation is actually increased by the addition of orthophosphate and inhibited by poly phosphatesMechanisms are very complex and not fully understood.

Milk gels, Puddings & CheesecakeDry mixes are blended with milk, blended and refrigerated to gelGelation is by the action of: TSPP in the presence of calcium acetate MCP as the gelation acceleration with acetylated monoglyceridesCarrageenan in the presences of TSPP, STP or TSP with an additional calcium phosphate for puddingsInstant cheese cake also used TSPP and MCP. Milk is added, poured into a graham cracker crust and refrigerated ready to serve in 15 minutes

Cheese applicationsProcessed cheese requires a calcium sequestering agent to remove calcium from the casein micelle of the cheese in order to emulsifiy the fat and turn the casein into a thermal plastic materialIn addition, the citrates and/or phosphates provide a buffering capacity to stabilize the system in the pH range of 5.4-5.6Blends of phosphates and citrates most commonly used, singly or in combinationCitrates 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 processed cheese and blend is used

Egg productsProtect whole egg or egg yolk against discolorationPolyphosphates stabilize eggs against the action of proteolytic enzymesSTP enhances the whipping properties of egg whites.SMP stabilized egg whites to pasteurization, with triacetin to prevent loss of foamingMSP reduced tendency for overbeating of egg whites by reducing pH to 8.0

Other Dairy (non cheese) ApplicationsIncrease solubility of nonfat dry milkIncrease whipping properties of caseinStabilize frozen desserts to fat agglomerationStabilize coffee whiteners during heat treatment and concentration and prevent featheringtype depends on other ingredients (DSP and KSP commonly used with the potassium salt giving less flavor and being more soluble; SALP used in some instancesServe as buffers and stabilizing agents for protein films needed to make a stiff foam (DSP, DKP, TSPP)

Phosphates In Meat ProductsStabilize ColorPolyphosphates (SMPH) provide pH 6.5-6.6 to retard oxidation of natural meat pigments that accelerate at the normal ph of meat (5.2-6.0Increased TendernessPhosphates (SMPH, TSPP) cause dissociation of actomyosin and improve tenderness of all meats.Action not associated with pHPyrophosphates combine with magnesium to give muscle relaxation and improve tenderness

Phosphates In Meat Products (cont)Enhance binding Assist in extraction of actinomyosin and improves binding used for reformed meatIncreases moisture retentionSMHP increases juicinessSHMP decreases cooking lossesRetard OxidationDSP most effective STP, SHMP and SAPP +TSPP not effective