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Lecture XIII Starch Technology

Lecture XIII Starch Technology. Starch I. Intro/History I Biosynthesis Energy reserve for plants Product of photosynthesis Assimilation starch Reserve starch History Consumption. Starch I. Intro/History II Biosynthesis Energy reserve for plants Product of photosynthesis

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Lecture XIII Starch Technology

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  1. Lecture XIIIStarch Technology

  2. Starch I • Intro/History I • Biosynthesis • Energy reserve for plants • Product of photosynthesis • Assimilation starch • Reserve starch • History • Consumption

  3. Starch I • Intro/History II • Biosynthesis • Energy reserve for plants • Product of photosynthesis • Assimilation starch • Reserve starch • History • Consumption

  4. Starch I • Intro/History II • Biosynthesis • Energy reserve for plants • Product of photosynthesis • Assimilation starch • Reserve starch • History • Consumption

  5. StarchConsumption (Foods) CONSUMPTION OF STARCHES IN FOODS BY END USE (%)

  6. Starch II • Classification • By Source • By Processing Method • Manufacturing

  7. Starch II Classification by Source

  8. Starch II Classification by Process

  9. Corn Starch - Wet Milling 4 main fractions of the corn kernel 1. Germ 2. Fiber 3. Gluten 4. Starch

  10. Kernals 1 2 3 Corn Oil 4 5 6 7

  11. Schematic diagram of a clarifier and a separator

  12. Starch II • Manufacturing • Comercial Forms • Pearl - from drier • Powder • “Lump” - aggregates • Dried, precooked (pregelatinized)

  13. Starch III • Structure & Composition • Glucose Polymer • Amylose • Amylopectin

  14. Starch (Amylose), considered as a condensation polymer of glucose

  15. 60 Pea

  16. hilum Schematic model of starch granule organization. Dotted line = amylose molecule, solid line = amylopectin molecule (T. Kasemsuwan & J. Jane, 1994)

  17. ^ ^ ^ ^ ^ ^ Structrue of molecules in layer of a starch granule. Thickened areas represent micelles produced by association of chains hilum

  18. Starch Granules I Tapioca Granules Wheat Granules 1 g starch = 1x109 granules! Size = 2-100 m - i.e., 0.002 - 0.1mm 1 granule = 1013 molecules! Potato Granules

  19. Starch Granules II Rice Granules Corn Granules

  20. Starch Granules III Micrograph of Potato Starch Granules --> Micrograph of Potato Starch Granules (polarized light shows Maltese Cross) -->

  21. Amylose Amylose The Helical Structure Amylose Fractions Showing the Helical Structure

  22. Starch IIIClathrates Model of an iodine-filled amylose helix (Rundle, Foster, and Baldwin, 1944)

  23. Starch IIIClathrates • Structure & Composition • Glucose Polymer • Amylose • Clathrates Diagrammatic representation of a complex of a fatty acid molecule inside a segment of an amylose helix(Whistler & BeMiller, CHO Chem for Fd Scientists)

  24. Starch III • Structure & Composition • Glucose Polymer • Amylose • Clathrates • Analytical use • Amylopectin

  25. <-- 1,6 Linkage Amylopectin 1,4 Linkage ^^^ Amylopectin Amylopectin Branching

  26. Starch IV • Properties • Digestibility • Gelatinization

  27. Starch IV (Digestability) a-Amylase activity on Amylopectin, with formation of Dextrins of low MW (Advances in Enzymol., 12, 390 (1951))

  28. Starch IV (Digestability) Limit Dextrin is left b-Amylase activity on Amylopectin, with formation of Maltose and a high MW Limit Dextrin (Advances in Enzymol., 12, 394 (1951))

  29. Starch IV • Properties • Digestibility • Gelatinization (definition) • “The irreversible swelling of starch granules under the influence of heat and/or chemicals in an aqueous medium to give a starch paste. • During the swelling process amylose tends to leach from the starch granules and the amylopectin becomes fully hydrated. Viscosity rises and is at a peak when the granules are hydrated to their maximum extent and are in close contact with their neighbors. If heating (and/or mixing) continue, the granules then rupture, collapse and fragment.” (Nat’l Starch)

  30. Starch IV • Gelatinization (general)

  31. Amylose chains (Whistler & BeMiller, CHO Chem for Fd Scientists)

  32. Gelatinization Additional heat and/or shear vs Especially Amylose Retrogradation or “Setback” Cooling Gelation

  33. Starch IV • Properties • Digestibility • Gelatinization (general) • Retrogradation

  34. Starch IV • Properties • Digestibility • Gelatinization (general) • Retrogradation • “Fingerprinting” starches

  35. Torque Recorder Sensor Thermoregulator Container Bowl Stirrer Heating Element Cooling Probe Bowl Rotating Motor

  36. “Setback” Cooking Ease Peak Vis Stability D Stability

  37. Potato Tapioca Waxy Corn Wheat Changes in native starch during processing (Hndbk of HCs, CRC Press, 2000)

  38. Starch V • Physical Usage Forms • Dry • Gelatinized • Molecular dispersion • Dry film

  39. Starch V • Properties of Starch Forms • Dry I • Gelatinized • Molecular dispersion • Dry film

  40. Starch V • Properties of Starch Forms • Dry II • Gelatinized • Molecular dispersion • Dry film

  41. Starch V • Properties of Starch Forms • Dry II • Gelatinized • Molecular dispersion • Dry film

  42. Starch V • Properties of Starch Forms • Dry II • Gelatinized • Molecular dispersion I • Lipophilic starches • Starch Alkenylsuccinates • Emulsions • Encapsulation

  43. Starch V • Properties of Starch Forms • Dry II • Gelatinized • Molecular dispersion II • Lipophilic starches • Starch Alkenylsuccinates • Emulsions • Encapsulation

  44. Starch V • Properties of Starch Forms • Dry II • Gelatinized • Molecular dispersion • Dry films

  45. Starch V • Properties of Starch Forms • Dry films II • Vary Properties • soluble, insol, adhesives • Applications • Binding agents • Adhesives • Coatings • (all for paper, textile, adhesive, food, & pharmaceutical industries)

  46. Starch VI (Gelatinized) • Effect of other food ingredients I Effect of different sugars on gelatinization of 5% cornstarch in 100oC water bath

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