Candy and the Solid State of Matter:

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Candy and the Solid State of Matter Connecting
the Molecular to the Macroscopic World Richard
D. Ludescher Food Systems Summer Institute June
27-29, 2006
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Consider TheseKinds of Solid Candy

• Chocolate
• Hard Candy
• Gummi Bears
• How are their physical properties similar?
• How different?Why?

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Molecular Structure of Solid Candy

• Chocolate
• Crystalline Solid Cocoa butter matrix
• Hard Candy
• Amorphous Solid Sucrose solution
• Gummi Bears
• Soft Polymeric Solid Gelatin gel

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Chocolate Theobroma cocao
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Cocoa LiquorSugarCocoa Butter(Milk Powder)
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Cocoa Beans
Chocolate liquor
Roast Mill
Add cocoa butter, sugar, (milk powder, flavor)
Conch
Temper
Chocolate Manufacturing Process
Mold or Enrobe
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Chocolate Liquor The melangeur grinds chocolate
nibs into liquor
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Melts in Your Mouth (Not in Your Hand)
Chocolate Matrix is Crystalline Fat (Cocoa Butter)
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Cocoa Butter is made of Triglycerides
Tripalmitin
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Cocoa Butter Composition

• Palmitic acid (25)
• C160 16 carbon saturated fatty acid
• Stearic acid (35)
• C180 18 carbon saturated fatty acid
• Oleic acid (35)
• C181 18 carbon unsaturated fatty acid
• One cis double bond at C9
• Primarily P/StOP/St and P/StOO structures

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Cocoa Butter Crystals Proposed structures
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Crystal Forms of Cocoa Butter Chocolate Tempering
Tempered chocolate
Cocoa butter is a polymorphic fat It can form
six different crystal structures with different
melting points and properties
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Chocolate Fashion ShowChocolate Show New York,
November 8, 2005
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When Chocolate Goes Bad
Chocolate Bloom Formation of new crystals on
surface
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Chocolate Bloom
Tempered
Bloomed
Thermal abuse melts form V crystalsLiquid fat
migrates to the surface where it crystallizes
into unappetizing small, polymorphic crystals of
arbitrary form
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Hard Candy Saccharum officinarum
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Rock Candy Table Sugar Crystalline Sucrose
Hard Candy Lollipops Amorphous Glassy Sucrose
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Hard Candy Recipe Sugar 5 cupsCorn syrup 1
cupWater 1 cupFlavor 1-2 teaspoons oil of
peppermint, orange, anise, cinnamon, wintergreen,
cloves, or spearmint, etc.Color 1-2 drops of
food coloring (if desired) Mix sugars and water,
cook to hard crack stage (300?F), remove from
heat, add flavor, mix well, pour into molds and
cool. Store in sealed container.
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Glass Forms Because Crystallization is
Frustrated by High Viscosity of Liquid Sugar
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Properties of Amorphous Glassy Sucrose

• Solid-like
• Hard, rigid and brittle
• Liquid-like
• Can dissolve colors and flavors
• Supersatuated liquid
• Softens at high temperature Glass transition
  (Tg)
• Hard brittle below Tg
• Soft malleable above Tg

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Crystal Long Range Molecular OrderAmorphous
Glass No Long Range Order
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Rose Window Notre Dame, Paris One of the more
attractive applications of glass technology
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Sugar Sculpture American Culinary Federation
National Convention, 2003
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Triboluminescence Light emission after excitation
by rubbing or striking
Wintergreen (methyl salicylate)
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Triboluminescence of Sucrose(nitrogen emission)
Absorption and Fluorescence of Wintergreen
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Gummi Bears Hard Jell-O
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Gummi Bear Recipe Water Corn syrup Sucrose
GelatinCitric acid Coconut oilCarnauba
waxFlavors ColorsDissolve sugar and gelatin
in boiling water, add syrup, oil and wax, mix
well. Add citric acid, juice, and flavors and
colors. Pour into molds. Cool. Gelatin is added
at levels about 6x that used in Jello.
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Gelatin has been around for millennia, Jell-O for
about a century
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Sus scrofa The source of most food gelatin
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Jell-O is a Gel A 3-D Polymer Network
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Mechanism of Gel Formation in Jell-O
Dissolve gelatin in boiling water
Cool to T
Gelatin crosslinks to form polymer network
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Gelatin Triple Helix The Physical Crosslinks in
a Gelatin Gel