PHOSPHATES

1. PHOSPHATES • Phosphates 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).

2. PHOSPHATES (multiple forms)

3. PHOSPHATES (dehydration)

4. Phosphates have multiple pKas • pKa1~ 2.4 • pKa2~6.7 • Pka3 ~8.4 • In milk at pH 6.6 • Monophosphate/phosphoric acid – 43000/1 • Diphosphate/monophospaate – 0.8/1 • Triphosphate/disphosphate – 1/600000

5. Phosphate Nomenclature • 1.Orthophosphate - Salts Of Phosphoric Acid Monobasic, Dibasic, Tribasic • 2.Polyphosphates - Dehydration Products • A. Pyrophosphate - 2 P Atoms • B. Tripolyphosphate - 3 P Atoms • C. Sodiumhexametaphosphate - Mixtures P>4

6. Phosphates (GRAS, nutrient) 182.5210 Calcium glycerophosphate 182.5212 Calcium phosphate 182.52213 Calcium pyrophosphate 182.5301 Ferric phosphate 182.5304 Ferric pyrophosphate 182.5306 Ferric sodium pyrophosphate 182.5434 Magnesium phosphate 182.5455 Magnesium glycerophosphate 182.5628 Potassium glycerophosphate 182.8217 Calcium phosphate 182.8223 Calcium pyrophosphate 182.8458 Magnesium hypophosphite 182.8778 Sodium phosphate

7. Phosphates (GRAS) 182.6085 Sodium acid phosphate 182.6203 Calcium hexametaphosphate 182.6215 Monobasic calcium phosphate 182.6285 Dipotassium phosphate 182.6290 Disodium phosphate 182.6760 Sodium hexametaphosphate 182.6769 Sodium metaphosphate 182.6778 Sodium phosphate 182.6787 Sodium pyrophosphate 182.6789 Tetrasodium pyrophosphate 182.6810 Sodium pyrophosphate

8. Phosphates (GRAS) 182.1073 Phosphoric Acid 182.1087 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 phosphate 182.1810 Sodium tripolyphosphate

9. Orthophosphates (monomer

10. Orthophosphates • Help to stabilize pH in foods • Mono sodium phosphate (MSP)– used as an acidulate • Di (DSP) and tri sodium (TSP) phosphate – used to increase pH • MSP and DSP combinations generally used in buffering systems

11. Pyrophosphates (Dimer)

12. Trimers

13. Tripoly phosphates • Potassium tripolyphosphate • Only potassium polyphosphate is used in food • High cost • Only used when others phosphates are too astringent • Sodium tripoly phosphate • Only fully neutralized salt is used • Used in limited amounts in foods

14. Polymers of NaPO3 (>3) • Sodium hexametaphosphate (n=5-15) • PH 7.0, soluble • Sodium metaphosphate (n=50-100) • pH 6.2, soluble

15. Poly Phosphates • Polyphosphates 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)

16. Phosphate Functions • Sequester metal ions • Buffer • Increase water binding • Adjust pH • Anti-caking agent • Form ionic "bridges" • Interact with proteins, other charged hydrocolloids

17. Phosphates found in many foods – most common are: • Carbonated beverages • Cereal products • Dairy products • Egg products • Fruits and vegetables • Gums and gels • Meat products • Polyphosphates as microbial inhibitors

18. Phosphates in carbonated beverages • Mineral supplementation in some carbonated and non carbonated beverages • Iron and calcium phosphates – most common in non carbonated beverages • Complex metal ions • Prevent loss of carbonation caused by heavy metals (25-90% less CO2 needed in untreated water • Acidification • Common in cola beverages • Improve flow of powders in dry mixes • Tricalcium phosphate (TCP) most common in use and also assists in size distribution of the dry mix

19. Phosphates In Cereal Products • Leavening Agents • Decreased Cooking Time • Buffer pH in cereals during cooking • Dough Conditioners (SALP, acidic CP • Inhibition of enzyme activity (DSP) • Antioxidant activity (MSP & DSP) • Cheater • Mineral Enrichment • Color Improvement • Improved Tortillas by steeping corn in MSP,DSP or TSP (generally alkaline) • Use of high molecular weight

20. Phosphates as leavening agents • Largest use is in prepared mixes because of broad choice of phosphates with different rates of CO2 • Salts of phosphoric acid and its polymers used through neutralization to form acidic salts

21. Chemical Leavening • Reaction between sodium bicarbonate and acidic phosphate salt • The phosphate will have at least two replaceable hydrogen atoms • Phosphates provide • Acidification for release of CO2 • Buffering to provide optimum pH for baked product • Interaction with flour ingredients to provide optimum viscosity and elasticity in the dough or batter

22. Factors affecting leavening action • Proper selection of acidulation • Bubble size formed during mixing • Quality of the gluten in the flour • Viscosity during mixing • Type of emulsification of the system • Dough 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)

23. DRR for different phosphate salts

24. Evolution of CO2 (%) • 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 • SAPP (fast) 40 8 52

25. Notes on most commonly used phosphate leavening agents • Mono calcium phosphate (MCP) • Most rapid release of CO2 – complete during mixing – used in combination with slower acting to retain CO2 release during baking • Anhydrous coated calcium phosphate (AMCP) – cake mixes, self rising dough • Di-calcium phosphate (DCP) • Slowest release of CO2, generally all released during baking • Sodium aluminum phosphates(SALP) • Bland flavors • Used in a wide range of bakery products • Sodium acid pyrophosphates (SAPP) • Astringent • Only leavening agent usable for refrigerated dough • Commonly used for cake doughnut mixes (or with MCP)

26. Some combinations • Cake mixes • Use of highly emulsified shortenings, gives finer structure and reduces the amount of leavening agent needed • AMCP & SALP in white and yellow cakes • AMPC and SAPP or DCP in chocolate cakes, since CALP dulls the chocolate color • Self rising flours • AMCP because of stability • Blends of AMCP SALP give better flavor and more stability in conditions of high humidity • Pancake mixes • Combinations of MCP+SALP or MCP+SALP+SAPP to provide stability during frozen storage. Freeze/thaw stability • Prepared Biscuit mixes • Blends of 30-50% AMCP+50-70% SALP or SAPP

27. Phosphates In Dairy Products • Heat Stability • Age Gelation Stability • Emulsifying • Chelation Of Fe & Cu In Butter • Milk Gels (TSPP) • Control Of Gum Gelation • Prevents Churning Of Ice Cream • Melting Of Processed Cheese • Whipping Aid

28. Phosphates and the casein system of milk • Casein exists in milk as micelles that are stabilizes by colloidal calcium phosphate • Calcium ortho phosphate is involved in the formation and stabilization of the casein system • Many of the applications in the processing of dairy products involves interactions between phosphates and the casein or the calcium in the micelles

29. Heat stability • “salt balance” (ratio of citrate & phosphate to calcium and Magnesium) appears to control heat stability of evaporated milk • Addition of ortho phosphate stabilizes concentrated milk to retort sterilizations • UHT sterilization of concentrated milk gives different results with phosphates. Age gelation is actually increased by the addition of orthophosphate and inhibited by poly phosphates • Mechanisms are very complex and not fully understood.

30. Milk gels, Puddings & Cheesecake • Dry mixes are blended with milk, blended and refrigerated to gel • Gelation is by the action of: • TSPP in the presence of calcium acetate • MCP as the gelation acceleration with acetylated monoglycerides • Carrageenan in the presences of TSPP, STP or TSP with an additional calcium phosphate for puddings • Instant cheese cake also used TSPP and MCP. Milk is added, poured into a graham cracker crust and refrigerated – ready to serve in 15 minutes

31. Cheese applications • Processed 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 material • In addition, the citrates and/or phosphates provide a buffering capacity to stabilize the system in the pH range of 5.4-5.6 • Blends of phosphates and citrates most commonly used, singly or in combination • Citrates predominate in products made with young cheese • Phosphates predominate in products with aged cheese, SALP provides less flavor than DSP • Since both young and aged cheeses used in most processed cheese and blend is used

32. Egg products • Protect whole egg or egg yolk against discoloration • Polyphosphates stabilize eggs against the action of proteolytic enzymes • STP enhances the whipping properties of egg whites. • SMP stabilized egg whites to pasteurization, with triacetin to prevent loss of foaming • MSP reduced tendency for overbeating of egg whites by reducing pH to 8.0

33. Other Dairy (non cheese) Applications • Increase solubility of nonfat dry milk • Increase whipping properties of casein • Stabilize frozen desserts to fat agglomeration • Stabilize coffee whiteners during heat treatment and concentration and prevent “feathering”–type depends on other ingredients (DSP and KSP commonly used – with the potassium salt giving less flavor and being more soluble; SALP used in some instances • Serve as buffers and stabilizing agents for protein films needed to make a stiff foam (DSP, DKP, TSPP)

34. Phosphates In Meat Products • Stabilize Color • Polyphosphates (SMPH) provide pH 6.5-6.6 to retard oxidation of natural meat pigments that accelerate at the normal ph of meat (5.2-6.0 • Increased Tenderness • Phosphates (SMPH, TSPP) cause dissociation of actomyosin and improve tenderness of all meats. • Action not associated with pH • Pyrophosphates combine with magnesium to give muscle relaxation and improve tenderness

35. Phosphates In Meat Products (cont) • Enhance binding • Assist in extraction of actinomyosin and improves binding – used for reformed meat • Increases moisture retention • SMHP increases juiciness • SHMP decreases cooking losses • Retard Oxidation • DSP most effective • STP, SHMP and SAPP +TSPP not effective