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FOOD CHEMISTRY

FOOD CHEMISTRY. BY DR BOOMINATHAN Ph.D. M.Sc.,(Med. Bio, JIPMER), M.Sc.,(FGSWI, Israel), Ph.D (NUS, SINGAPORE) PONDICHERRY UNIVERSITY Fifth lecture 13/August/2012. Goals. Structural arrangements of different Gums: Carrageenans, Guar gum, Carbogum, Xanthan, and Gum arabic

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FOOD CHEMISTRY

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  1. FOOD CHEMISTRY BY DR BOOMINATHAN Ph.D. M.Sc.,(Med. Bio, JIPMER), M.Sc.,(FGSWI, Israel), Ph.D (NUS, SINGAPORE) PONDICHERRY UNIVERSITY Fifth lecture 13/August/2012

  2. Goals • Structural arrangements of different Gums: • Carrageenans, • Guar gum, • Carbogum, • Xanthan, • and Gum arabic • Composition • Physico-chemical properties of Gums • Applications of Gums in food industry

  3. Polysaccharides Ionic Gums Carrageenans Southern Bio-products Conference

  4. Carrageenan • Carrageenan • obtained by extraction with water or alkaline water of certain Rhodo phyceae (red seaweed). • It is a hydrocolloid • consisting mainly of the potassium, sodium, magnesium, and calcium sulfate esters of galactose and 3.6-anhydro-galactosecopolymers. • nonhomogeneous polysaccharides 3 types: Kappa, lambda, iota

  5. Three types of Carrageenans

  6. Carrageenans • Kappa • Lambda

  7. Structural changes of Carrageenans at different temperatures Cold Hot Cold Gelation Ca 2+ double helices are believed to nest coiled state double-helical structures In a hot solution, the polymer molecules are in a coiled state. As the solution is cooled, they intertwine in double-helical structures. As the solution is cooled further, the double helices are believed to nest together with the aid of potassium or calcium ions.

  8. Comparisons of different Carrageenans • CharacteristicsKappa Iota Lambda • Solubility • 20° C water no no yes  • 80° C milk yes yes yes  • 20° C milk no no thickens       • Gelation • With addition of: K+ Ca++ None      • Stability • Freeze – thaw no yes yes  • pH > 5 stable stable stable  • Syneresis yes no no  • Salt tolerance poor good good

  9. Protein - Carrageenan Interactions • Protein (milk) with a negative charge Protein (milk) with a positive charge • Reacts with casein milk protein • The thickening effect of kappa-carrageenans in milk is 5–10 times greater than • it is in water. • Useful in the preparation of chocolate milk, icecream, evoporated milk etc.

  10. Carrageenan: Application of carrageenan in meat protection • 3 categories of meat: 1. pale, soft, and exudative (PSE) • Due to postmortem generation of lactic acid 2. dark, firm, and dry or non-exudative (DFD) 3. "normal" meat • acceptable • subjectively between PSE meat and DFD meat • Function: Carrageenan + soy protein: • Prevents occurrence of PSE meat Concept: Use of carrageenan is to hold water and maintain water content, and therefore softness of meat products, such as sausages, during the cooking.

  11. Carrageenan softens meats • Carrageenan is a water-soluble polymer, also known as a gum, that is used as a fat substitute in processed meats and can be found in condensed milk and some soy milk products. • Normally, fat serves the purpose of maintaining softness, but because of the binding power of carrageenan for protein and its high affinity for water, • Carrageenans can be used to replace in part this function of natural animal fat in lean products.

  12. … However • Carrageenan may cause stomach lesions, cancer • Strawberry cheesecake like this may be stabilized and thickened with carrageenan. • Containers of pudding, ice cream, yogurt, or cottage cheese may include the ingredient carrageenan, a thickener derived from red seaweed. • For decades, it has been presumed to be safe to eat, but new research from a medical doctor on the faculty of the University of Iowa shows that presumption may be wrong.

  13. Typical Dairy Applications of Carrageenan • Typical Dairy Applications of Carrageenan • Milk Gels • Cooked flans (open pastry filled with fruit or custard) or custards (Sweetened mixture of milk and eggs baked, boiled or frozen) • Gelation K, K + I • Cooked prepared custards • Thickening  • Gelation K, I, L • Pudding & Pie Fillings • Dry mix cooked with milk • Level starch gelatinization • Ready-to-eat • Syneresis control, bodying

  14. Typical Dairy Applications of Carrageenan • Whipped products • Whipped cream Stabilize overrun • Aerosol whipped cream • Stabilize overrun & emulsion • Cold prepared Milks • Instant Breakfast • Suspension, bodying agent • Shakes • Suspension, bodying

  15. Carrageenan: Summary • Structure: • Galactose backbone • Ester sulfate gives negative charge • Properties: • Gels with potassium (Kappa) • Gels with calcium (Iota) • Non-gelling (Lambda) • Applications: • Good stabilizer for milk proteins • Suspender for chocolate in milk • Part of ice cream stabilizer mix • Water gels

  16. Questions • Commercial carragennan contains: 1. Kappa 2. Iota 3. Lamda 4. a mixture of above • The viscosity of carrageen is quite stable over a wide range of pH values because • 1. sulfate half-ester groups are always ionized • 2. Phosphate groups are never ionized • 3. Phosphate groups are always ionized • 4. Nitro groups are always ionized

  17. Questions • Lambda carragennan contains: 1. the maximum no. of sulfates 2. the lowest no. of sulfates 3. only one sulfate 4. none • Carrageen softens meat due to its • 1. binding power for protein • 2. high affinity for water • 3. both

  18. Non-ionic Gums • Guar gum & Carobgum

  19. Guar gum

  20. Guar Gum Guar gum is the ground endosperm of seeds Guar gum Monomer: galactose, mannose (galactomannan) Bonding: -1,6/-1,4

  21. Galactose Glucose Mannose

  22. Guar gum Monomer: galactose, mannose (galactomannan) Bonding: -1,6/-1,4 a main chain of b-D-mannopyranosyl units joined by (1-- 4) bonds with single-unit a-D-galactopyranosyl branches attached at O-6 Galactose Mannose Mannose

  23. Guar Gum • It produces the highest viscosity of any natural, commercial gum • Galactomannan (Mannose (1-4) + Galactose (1-6) every other Mannose • Galactomannans consist of MW 220,000 ± 20,000 • Particle size affects viscosity and hydration • Cold water swelling - Turbid solutions

  24. Guar Gum • Hydration increased by heating • High water binding • High viscosity form - up to 100,000 CP • Low viscosity from - up to 10,000 CP • Modifies properties when used with: • Carrageenan • Xanthan

  25. Guar Gum • Characteristic of different grades of Guar Gum • Grade Cold Viscosity. Hydration Rate Dispersability • Coarse 2,700 Slow Excellent • Medium 3,800 Moderate Excellent • Fine 4,000 Fast Fair • Powder 4,300 V. Fast Poor

  26. Food Uses Ice cream prevents ice crystal formation, slows meltdown, improves heat shock resistance Salad dressing viscosity Cheese improves spreading

  27. Guar gum uses in food industry • Ice creams: Smooth creamy texture • Bakery products: Texture, moisture retention • Noodles: Moisture retention, machine runnability • Beverages: mouth feel • Meat: Binder, absorb water • Dressings: Thickener, emulsion stabilizer

  28. Carobgum

  29. Carobgum Carobgum is the ground endosperm of seeds

  30. Carobgum • Carobgum • obtained from the endosperm of the Carob or locust seed (Ceratonia siliqua). Southern Bio-products Conference

  31. Seed Gum Monomer: galactose, mannose (galactomannan) Bonding: -1,4/-1,6 (branch) Carobgum

  32. Carob Gum Galactose Mannose Galactomannan (D-Mannose (1-4) with Galactose (1-6) every 4th mannose

  33. Carobgum • Galactomannan (D-Mannose (1-4) with Galactose (1-6) every 4th mannose • Molecular weight 330,000 ±30,000 • Neutral - relatively unaffected by ions, pH. • Not soluble in cold water • Fully hydrated if heated 10 minutes at 80° C • Solutions are turbid, off-white • Modify properties of • Carrageenan • Xanthan Gum

  34. Carobgum • retards ice crystal growth • shows viscosity synergy with xanthan. Southern Bio-products Conference

  35. Guar gum and Carobgum

  36. B) Non-ionic gums Guar gum and Carobgum No effect of pH and ions (salts) since they are uncharged Guar gum has galactose side-groups on every other mannose unit (2 monnose:1 galactose) while carobgum does not have uniform distribution (4 mannose:1galactose) or irregular Gums-Guar gum and Carobgum

  37. Gums-Guar gum and Carobgum Carbogum

  38. B) Non-ionic gums Guar gum and Carobgum: Guar gum : soluble in hot/cold water; very viscous solutions at 1% ; and it forms gels and films at 2-3% Guar gum produces the highest viscosity of any natural, commercial gum Used in Ground meats, salad dressings and sauces…… Carobgum: Soluble at 80/90oC; very viscous solutions; Synergises with xanthan gum or carrageenan Used as a Binder in meat products and in frozen desserts Gums-Guar gum and Carobgum

  39. Questions Guar gum and carbogum are examples for: 1. Ionic gums 2. Non-ionic gums 3. Both 4. None • pH and ions can change the property of Guar gum and carbogum • True • False • Only pH • Only ions

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