NDFS 250

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  1. Quick breads (as opposed to yeast breads)
    General class of baked products that don’t use microorganisms to produce the carbon dioxide for leavening (rapid leavening without fermentation).
  2. Quick Bread Examples 
    Examples: popovers, cream puffs, muffins, biscuits, waffles, pancakes (griddle cakes), cakes, cake donuts
  3. Quick Breads
    Ingredients and their functions
    Structure, via gelatinized starch and gluten
  4. Quick Breads   
    Ingredients and their functions
    •Hydration of starch and protein; dissolving of sugar, salt, leavening agents; steam for leavening
  5. Quick Breads 
      Ingredients and their functions
    •Taste, influences flour hydration
  6. Quick Breads 
      Ingredients and their functions
    •Leavening agent
  7. Quick Breads  
     Ingredients and their functions
    •Tenderness, inhibits gluten development and shortens the texture, air incorporation for leavening
  8. Quick Breads  
     Ingredients and their functions
    •Tenderness, sweetness, interferes with gluten formation
  9. Quick Breads   
    Ingredients and their functions
    Air incorporation, emulsification, structure
  10. Reasonable balance needed
    • Structural ingredients (flour, egg) 
    •              vs,
    • Tenderizing ingredients (fat, sugar)
  11. Ingredient adjustments sometimes made for higher altitudes (3000 ft +). Why? What changes would you suggest?
    Reduction of leavening agent

    Due to lower atmosphereic preassure

    Increased water due to lower boiling point and greater evaporation

    More flour to increase structure to hold leaning gases
  12. Over Mixing 
    Over-mixing leads to gluten development and tough texture – especially in viscous batters

    More flour to increase structure to hold leaning gases
  13. •3 main purposes to mixing 
    • To distribute leavening agents uniformly throughout the batter
    •    •e.g., sifting leavening with flour
    • •To distribute fat uniformly throughout the flour
    •    •e.g., cutting fat into flour, creaming sugar and fat, or adding melted fat/oil with liquid ingredients
    • •To distribute liquid uniformly
    •   •e.g., stirring liquid and dry ingredients to form the dough or batter
    •    •Dissolves the salt, sugar, acid and soda
    •    •Should minimize loss of leavening gas
  14. Baking batters and doughs
        •Oven temperature and placement
    •Bake in hot oven (375 -450 °F is common)

    •Adjust rack to place product in center of oven

    •Temperature in product interior only gets to boiling point of water
  15. Baking batters and doughs
       •Changes in batters and doughs during baking
    •Fat melts and mix becomes fluid

    •Insoluble ingredients solubilize with heat

    •Baking powder continues to form carbon dioxide

    •Heat expands air and carbon dioxide, increasing size

    •Proteins in flour and egg denature

    • •Starch gelatinizes
    • •Part of water is converted to steam

    •Evaporation of water from surface slows and surface gets hot enough to brown hotter than 212.
  16. •Beat
    •To combine with a regular over-and-over or circular motion, to make smooth (e.g., popover) or to incorporate air (e.g., egg white)
  17. •Blend
    •To combine thoroughly (e.g., melted chocolate in a batter)
  18. •Cream
    •To work sugar crystals into fat to incorporate air (e.g., shortened cakes)
  19. •Cut
    •To progressively subdivide fat into flour (e.g., pastry)
  20. •Fold
    • •To gently incorporate one ingredient (e.g., egg white meringue) into another (e.g. waffle batter) using a knife, spatula or flexible
    • scraper.  Text gives details
  21. •Knead
    •To stretch, fold, and press dough gently to form and arrange strands of gluten (biscuit, yeast bread dough)
  22. Mix
    •To distribute ingredients using any technique suitable to the ingredients
  23. Stir
    •To combine with a circular motion, usually using a spoon
  24. Whip
    •To beat rapidly for the purpose of incorporating air
  25. Muffins: Method of mixing
    Add liquids to presifted dry ingredients. Mix just enough to barely dampen the dry ingredients.  It will still be lumpy.
  26. Muffins: Method of mixing
    •Dry Ingredients:
    •Sift baking powder with flour or stir in thoroughly

    •Essential for uniform gas cells in crumb structure

    •If using plastic fat, cut into sifted dry ingredients
  27. Muffins: Method of mixing
    •Liguid Ingredients: 
    •Blend eggs and milk (but not to a foam)

    •Protein is for binding and structure, not to incorporate air

    •If egg is not well blended, the crumb around some gas cells will be thick and tough

    •If using liquid fat, add to dry ingredients at the same time as milk and eggs are added
  28. Describe the qualities of properly made muffins
    Thin uniform golden brown crust symetrical top similar to caulifloour holes in crumb are round and medium sized light anad tender texture 
  29. Should a fast acting or double acting baking powder be used for muffins? Why?
    Ideal in a muffin is fast.  You want it to rise quickly not in the oven where it would break the crust 
  30. Biscuits
    1.Sift baking powder with flour.

    2.Cut plastic fat into dry ingredients (to corn meal texture).

    3.Add milk all at once.

    4.Stir until mixture stiffens.

    5.Place dough on lightly floured surface and knead 10-20 times.

    Dough tolerates and requires manipulation to develop gluten.
  31. •Shortened Cake
    •A cake containing fat, which shortens gluten development
  32. •Chiffon Cake
    •A cake containing fat (in the form of oil), cream of tartar, and more eggs than shortened cake.
  33. •Meringue cakes:
    Angel food cake, Sponge cake
    • •Cakes containing egg white that is whipped into a meringue. 
    • Sponge cake also contains beaten egg yolk.
  34. Beta/Beta Prime
    Big crystals in beta, smaller in beta prime.

    ♦Beta-prime crystals are best for creaming

    •Small and fine crystals incorporate small and fine air bubbles
  35. Effect of emulsifier on dispersion of gas cells in cake batter
    Makes a major difference in viscosity of batter and texture of final product.

    • With emulsifier:
    •     Fat and air more evenly dispersed
  36. Shortened Cakes Structure
    O/W emulsion  (fat globules dispersed throughout aqueous phase)

    Foam (air-in-fat dispersion)

    Aqueous phase (has ingredients in true solution, colloidal dispersion, and suspension)
  37. Shortened cakes Changes during baking 
    1  Fat melts.

    2  CO2 collects in air cells.

    3  As batter heats convection currents and expanding gases set constituents in motion. (see next slide)

    4  Heat enlarges gas cells.

    5  Internal pressure inside cake causes violent movement in batter (especially middle third of baking cycle).

    6  Gas cells, lubricated by mobile lakes of fat, are pushed about.

    7  Gas cells expand and rupture; resistance provided by protein coagulation and starch gelatinization.

    8  Evaporation of water from surface.
  38. Shortened cakes: Conventional Method 
    1. Cream sugar with plastic fat

    2. Eggs added and blended with creamed fat and sugar

    3. Portion (1/2) of both liquid and dry ingredients added and stirred into creamed mass

    4. Repeat for second portion
  39. Shortened cakes: Muffin method
    1 Blend eggs and milk, and add with melted fat

    2 Sift dry ingredients together

    3 Stir liquid ingredients into dry ingredients
  40. Shortened cakes:
    Muffin method Results
    Compared to conventional method, results in smaller volume, coarser crumb (texture), and quicker staling, since ingredients are not as well dispersed. 

     Advantage is less time and work needed, and is acceptable when eaten warm.
  41. Pastry
    —A steam-leavened baked good (often in the form of a filled crust) made from dough with a high ratio of fat to flour, prepared  in a manner to enhance flakiness and tenderness

    —Examples:  Pie crust, puff pastry
  42. Pastry
    Ingredients and their function
    •Physical structure for flakiness

    •Gluten development
  43. Pastry Ingredients and their function
    Flour Fat Water
  44. Pastry
    Ingredients and their function

    •Shortens gluten development by water-proofing flour

    •Breaks up texture to create flakiness

    •When properly dispersed, separates layers of flour
  45. Pastry
    Ingredients and their function
    •Steam for leavening, which helps produce flakiness

    •Gluten development

    •Hydrates flour particles 
  46. Pastry 

    •Tender and flaky

    •Superior in flavor
  47. Pastry 
    •Tender and flaky
  48. Pastry
    •Tender but not flaky
  49. Effect of Flour Type
    Image Upload
  50. —Pastry tenderness
    —Soft texture that is characteristic of good pastry

    Due to high fat concentration; affected by extent of gluten development and its distribution
  51. —Pastry flakiness
    Horizontal layering effect; depends on incomplete blending of fat and flour; contributing factors are cutting of cold, solid fat, use of cold water and chilling of dough. 
  52. —Pastry flakiness
    As water droplets heat up and turn to steam, the water vapor pushes upward and outward, encountering the fat barriers

    —The pressure from the steam pushes against the fat layer and lifts the dough

    —The steam moves horizontally along the fat barrier until it can move upward again – which shortens the texture and also enhances flakiness
  53. Laminated pastries
    •Puff pastry, croissants
  54. Causes of Pastry Defects
    too tender
    •Oil instead of plastic fat

    •Warm fat

    •Pastry flour

    •Cutting fat excessively

    •Under manipulation

    •Too little water
  55. Causes of pastry defects 
    too tough
    •Too little fat

    •Excess flour on board

    •Cutting fat insufficiently

    •Too much manipulation

    •Too much water
  56. Whipped cream foams
    •Stabilized by rigid, fragile structure formed by clumping of fat globules on surface of air cells

    •Whipping incorporates air into liquid

    •Contains fat droplets with their emulsifiers

    •Film of water thins and fat globules orient in this film as air is incorporated

    •Fat globule membrane is disrupted by whipping

    •Globules stick together imparting stiffness to the foam

    •Requires cool temperature; otherwise fat globules coalesce instead of clump
  57. Egg white foams
    • Protein denatures, with hydrophobic groups orienting toward the air.  This lowers the surface tension of the water,
    • facilitating foam formation
  58. Foam
    Image Upload 
  59. Egg white foams
    •Foamy,  transparent

    •Protein not denatured enough

    •Liquid drains around large air cells and they coalesce
  60. Egg white foams
    •Properly Beaten
    •Liquid around cells is thin and egg white thickens

    •Surface protein denaturation (unfolding) causes stiffness
  61. Egg white foams
    •Dry, curdled appearance

    • •Surface denatured protein becomes insoluble and no longer
    • elastic

    •Liquid drains from foam and air cells coalesce
  62. Sponge Cake
    1Yolks beaten until thick (portion of sugar may be beaten in).

    2Egg white beaten with part of sugar and made into meringue.

    3Flour sifted with remainder of sugar and folded into egg yolk (excessive folding should be avoided).

    • 4Yolk/flour mixture and egg whites
    • are combined by folding (fold no longer than necessary).
  63. Angel Food Cake
    Ingredients nand their function
    Cake flour
    •Structure; toughening effect 
  64. Angel Food CakeIngredients nand their function

    •Elevates coagulation temperature of proteins
  65. Angel Food CakeIngredients nand their function
    •Lemon juice (or cream of tartar or other
    •Fine, tender, white crumb (whitens the anthoxanthin  igments in flour)

    •Stabilizes foam; prevents collapse

    •Increases cake volume (less shrink during baking)
  66. Yeast
    Made from dough leavened with carbon dioxide formed by microorganisms
  67. Wet yeast (caked or compressed yeast)
    Shorter shelf-life
  68. Dry yeast

    •Instant/rapid rise (smaller size; more active strain)
  69. •Essential Yeast Bread Ingridients
    Flour: Gluten network; starch;  a and b amylases

    Liquid (water or milk): Dissolution of salt and sugar; hydration of flour; dispersion and growth of yeast; participates in enzymatic hydrolysis of starch

    Yeast: Leaven, flavor

    • Salt : Taste; stabilizes or controls yeast fermentation; favors
    • amylase activity; inhibits protease activity
  70. •Usually included
    Yeast Bread Ingridients
    Sugar: Substrate for fermentation; flavor

    • Fat: Tenderizes; increases loaf volume, keeping quality, slicing
    • properties
  71. •Sometimes includedYeast Bread Ingridients
    •Eggs: Provide rich appearance; stretch-ability of dough 
  72. Proportions of Ingredients in Bread
    Image Upload
  73. ♦Milk

    is it typically scalded?
    Denaturesserum proteins and other loaf depressenet factors

    Otherwisedough is sticky and has a poor volume 
  74. ♦Benzoyl peroxide 
  75. Manipulation of yeast dough
    Straight dough method
    ♦Ingredients combined and dough kneaded before allowed to rise; method is long, but gives good texture.
  76. Manipulation of yeast dough
    Sponge method
    ♦Yeast, liquid, and part of flour are combined; allowed to rise until spongy and light

    ♦Remainder of flour (with salt and fat) is added to sponge; dough kneaded and allowed to rise 

    ♦More handling, but more tolerant to time and temperature variations than straight dough method
  77. Manipulation of yeast dough

    Sponge method
    ♦Yeast, liquid, and part of flour are combined; allowed to rise until spongy and light

    ♦Remainder of flour (with salt and fat) is added to sponge; dough kneaded and allowed to rise 

    ♦More handling, but more tolerant to time and temperature variations than straight dough method
  78. Manipulation of yeast dough
    ♦High proportion of liquid, so gluten is developed by stirring rather than kneading; thus, it is fast

    ♦Results in open grain and uneven surface

    ♦Best for soft and rich doughs
  79. Gluten Development
    Incorporation of water into flour
    ♦Flour particles and protein bind water molecules; time is required for complete hydration
  80. Gluten development
    Mechanical manipulation –kneading/stirring
    ♦Hydrated flour particles are manipulated, and gentle folding and stretching allows molecules to interact, developing elasticity

    ♦Stretching and folding is a shearing process which brings order to the random distribution of gluten components
  81. Yeast Bread
    Straight Dough Method
    1.Hydrate/activate yeast

    2.Mix dry ingredients

    3.Mix wet ingredients

    4.Combine ingredients


    6.Allow to rise

    7.Punch and shape

    8.Proof (2nd rise)

  82. Punching
    Keeps gluten films around gas cells from being overstretched.

    Subdivides gas cells to create more smaller cells and finer crumb.

    Redistributes nutrients so yeast can access them.
  83. Proofing
    Allowing dough to rise again after shaping and placing in baking pan. Done in warm, humid proofing box.

    27-30 ºC (80 ºF) is optimum temperature
  84. First stage
    ♦25% of baking period.

    ♦400-425°F oven temperature; 55-60oC internal temperature causes dough to be more fluid initially.

    • ♦Amylases active – conversion of starch to dextrins
    • reduces water binding capacity of flour.

    ♦CO2 production is rapid and, with heat, gas cells expand.  80% of expansion occurs during this stage.
  85. Second stage
    ♦50% of baking period.

    ♦Maximum internal temperature of 100°C is reached.

    ♦CO2 production stops (yeast dies).

    ♦Amylase inactivated.

    ♦Gluten structure sets.

    ♦Starch partially gelatinizes.
  86. Baking
    Final stage
    ♦Internal structure firms.

    • ♦Crust develops via surface drying and nonenzymatic
    • (maillard/caramelization) browning. 

    • ♦Lowering oven to 350 °F after first 10-15 minutes
    • prevents too much browning of crust.
  87. Staling of bread
    Once bread cools, staling beginsand continues over several days
    ♦Crust becomes tough and leathery

    ♦Crumb becomes rigid, harsh and crumbly

    ♦Off flavor, probably due to lipid oxidation
  88. Staling of bread
    Attributed to 
    ♦Retrogradation of amylopectin in the pasted granules
  89. Staling of bread
    Prevented by
    ♦Adding monoglycerides to dough, which interact with starch

  90. Staling of bread
    Refreshed by
    ♦Heating to 60 C
Card Set:
NDFS 250
2012-11-17 03:44:32
food science

NDFS 250 2nd to last quiz
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