How to Make Chocolate for Your Special Valentine: Flowers ... · “How to Make Chocolate for your...
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Natural, Sustainable Innovation: L’Oréal’s Commitment to Renewable Materials and Eco-Friendly Processes
Michel Philippe, Senior Research Associate and Sustainable Innovation Manager, L’Oréal
Xavier Marat, Group Leader, Advanced Research, L’Oréal David Constable, Science Director, ACS Green Chemistry Institute
Thursday, February 23, 2017
Fighting Cancer: Epigenetic Targets for Oncology Session 2 of the 2017 Drug Design and Delivery Symposium
Stuart Conway, Professor of Organic Chemistry, University of Oxford Sharan Bagal, Senior Medicinal Chemist, AstraZeneca
Discover the Chemistry of Candy, Chocolate, and Ice Cream in Rich’s Past ACS Webinars!
“Sweet Science: Chocolate Chemistry for Valentine's Day”
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“Sweet Science: Having Fun with Candy Chemistry”
See the Slides and Edited Webinar Here! http://bit.ly/candychem
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“Halloween Candy Chemistry: Caramels, Gummies, Jellies, and
Candy Corn”
See the Slides and Edited Webinar Here! http://bit.ly/candychem2
“Ice Cream Chemistry”
See the Slides and Edited Webinar Here!
http://bit.ly/IceCreamChemistry2
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www.acs.org/acswebinars Slides available now! Recordings are an exclusive ACS member benefit.
“How to Make Chocolate for your Special Valentine: Flowers Bloom, Chocolate Shouldn't”
Contact ACS Webinars at [email protected] ®
Bill Courtney Food Chemist and Grant
Specialist, Washington University
School of Medicine
Rich Hartel Professor of Food Engineering,
University of Wisconsin-Madison
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• Cacao trees grown in tropical climates – Within 15° of equator
• Sources – Africa: Ivory Coast, Ghana – Indonesia/Malaysia – Brazil
• Cocoa beans grow inside pods – Harvested, beans removed, fermented, dried
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Cocoa beans
Pressing Grinding
Cocoa butter
Cocoa powder
Roasting
Winnowing Nibs
Shells (10-18%)
Chocolate liquor
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• Ground cocoa nibs containing a mixture of
cocoa solids and cocoa butter
• The primary ingredient for making chocolate
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• Nibs (ground)
– 48-57% fat - cocoa butter
– 2-3.5% water
– 40-50% cocoa solids
• starch, fiber and gums, etc.
• Alkaloids
– 0.8 - 1.3% theobromine
– ≈0.2% caffeine (some people say there is no caffeine in chocolate)
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mix sucrose
chocolate liquor
milk powder
refine
conch lecithin
cocoa butter
Particle size
reduction
Smooth
flavors
Ground
cocoa beans
Melted chocolate
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About 60-70% particles
Sugar crystals,
Cocoa solids,
Milk powder
30-35% cocoa butter
Melted chocolate, cocoa
butter is liquid
Solidified chocolate, cocoa butter is partially crystalline
About 0.5% water in normal chocolate
Probably associated with sugar crystals and cocoa solids
About 0.2-0.3% lecithin
Coats sugar particles and cocoa solids, the hydrophilic components
From Mark Auty, DPC, Moorepark
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temper
molded piece
enrobed candy bar
chocolate
fountain
Crystallize
cocoa butter
deposited drop
Melted chocolate
www.sci.mus.mn.us/sln/tf/c/cro
sssection/cbk.html
www.hersheys.com/kisses/ab
out/making.asp www.dessertcarnival.com/
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• Controlled crystallization of the triglycerides in
cocoa butter
Tempering Start fat Crystallization
Molding or Enrobing Continue fat Crystallization
Liquid
chocolate
Solidified
chocolate
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• It doesn't solidify very well
• Molded pieces don't contract from the mold
• It isn't glossy
• It develops unsightly spots within hours to days
What happens if you don't temper chocolate? (multiple possible answers)
Cocoa Butter Crystallization
What happens if you don’t temper chocolate?
1 day to a week 2 weeks Just after making
Before
Bloom
Light
Brown
Dark
Brown
Sugar (%) 34 43 34
Fat (%) 38 21 39
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TE
MP
ER
AT
UR
E
higher
lower
Liquid structures form in lipid
melts as temperature decreases
below melting point
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’
Liquid
Tem
per
atu
re
Tm -
Tm - ’
Tm -
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Nucleation Rate
• Different polymorphs form at different temperatures,
with rates of formation dependent on temperature.
TEMPERATURE
RA
TE
’
SIZE
GIB
BS
FR
EE
EN
ER
GY
Gcrit
’
29
30
• 23.3 C
• 25.5 C
• 27.5 C
• 33.8 C
• 36.3 C
What is the melting point in degrees Celsius of cocoa butter?
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Polymorph Melting Point
(°C)
∆H (cal/g)
I 17.3 -
II 23.3 20.6
’2 III 25.5 26.9
’1 IV 27.5 28.1
2 V 33.8 32.7
1 VI 36.3 35.4
• Crystallizes slowly • Desired form in chocolate
• Form associated with bloom
(Wille and Lutton, 1966)
• Crystallizes rapidly
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Tempering
50oC
32oC
26-27oC
30-32oC
Time
Tem
per
atu
re
Melt
Cool - no crystallization
Form mix of crystals
Melt out unstable polymorphs
1-3% crystals
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Cocoa Butter
One stable seed
33
’
Liquid
Tem
per
atu
re
Tm -
Tm - ’
Tm -
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1. Without Seeds
2. One seed
3. 0.00055% seeds
4. 0.027% seeds
5. 0.137% seeds
1. Without Seeds
2. One seed
3. 0.00055% seeds
4. 0.027% seeds
5. 0.137% seeds
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0.00055%
seeds
after 120 min.
0.027% seeds
after 90 min.
0.137% seeds
after 60 min.
As seeds amount increased, crystallization took
less time to reach upper level of solid fat content and
the size became smaller – the result, a smooth surface.
0.137% Seeds 0.027% Seeds 0.00055% Seeds
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0
5
10
15
20
25
30
0.0001 0.001 0.01 0.1 1
CB Seeds in Fat (%)
Lig
ht
Col
or A
rea
(%)
0
5
10
15
20
25
30
Marble Temp
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Tempering
• In order to develop the desired crystalline structure in chocolate, the crystallization process must be carefully controlled
– tempering
• formation of proper number of seed crystals of correct size and polymorph ( V form desired)
– first cool to low temperature (26-27°C) to form unstable polymorphs and then warm up to higher temperature (32°C) to promote formation of desired crystal structure
– cooling tunnel • maintain desired crystal size and polymorph
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Good tempering
• proper flow properties of tempered mass
• rapid setting upon cooling
• high gloss in final product
• maximum contraction (mold release)
• resistance to fat migration and bloom
Under tempering • insufficient seed to crystallize mass
• low gloss in final product
• less contraction
• rapid bloom formation
Over tempering • higher viscosity
• less gloss in final product • less contraction
Tempered Chocolate? 40
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• Automated tempering cycle
– Melt chocolate in kettle, heat to 110°F
– Cool to 85-90°F and add more chocolate in back
side of kettle
– The fresh chocolate partially melts, seeding the
cooled chocolate with appropriate cocoa butter
crystals
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• 75-77 F
• 81-83 F
• 85-87 F
• 88-90 F
• 91-93 F
When hand tempering, what temperature, in Fahrenheit, is needed for dark chocolate?
Pour a portion of melted
chocolate onto slab and
work with spatulas
Return crystallized mass
back to bowl
Check temperature If ≈ 88-90°F, it’s
tempered
If >92°F, repeat marble
work
Mold chocolate, dip
strawberries, etc.
Melt
Cool - no crystallization
Form mix of crystals
Melt out unstable polymorphs
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• Did you get your chocolate or tempered or not?
• Well tempered chocolate:
– Solidifies to the touch in a minute or so.
– Releases easily from the mold • Good contraction
– Has glossy surface • Small crystals reflect light
– Good snap • Fine internal structure
– Resistant to bloom • Retains gloss for long time
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0°C cooler
Sample
Thermocouple Temperature-time recorder
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Over tempered GOOD TEMPER Under tempered
time
tem
per
atu
re
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www.acs.org/acswebinars Slides available now! Recordings are an exclusive ACS member benefit.
“How to Make Chocolate for your Special Valentine: Flowers Bloom, Chocolate Shouldn't”
Contact ACS Webinars at [email protected] ®
Bill Courtney Food Chemist and Grant
Specialist, Washington University
School of Medicine
Rich Hartel Professor of Food Engineering,
University of Wisconsin-Madison
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Discover the Chemistry of Candy, Chocolate, and Ice Cream in Rich’s Past ACS Webinars!
“Sweet Science: Chocolate Chemistry for Valentine's Day”
See the Slides and Edited Webinar Here!
http://bit.ly/chocolatechem
“Sweet Science: Having Fun with Candy Chemistry”
See the Slides and Edited Webinar Here! http://bit.ly/candychem
www.acs.org/acswebinars
“Halloween Candy Chemistry: Caramels, Gummies, Jellies, and
Candy Corn”
See the Slides and Edited Webinar Here! http://bit.ly/candychem2
“Ice Cream Chemistry”
See the Slides and Edited Webinar Here!
http://bit.ly/IceCreamChemistry2
Upcoming ACS Webinars www.acs.org/acswebinars
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Contact ACS Webinars ® at [email protected]
Thursday, February 16, 2017
Natural, Sustainable Innovation: L’Oréal’s Commitment to Renewable Materials and Eco-Friendly Processes
Michel Philippe, Senior Research Associate and Sustainable Innovation Manager,
L’Oréal
Xavier Marat, Group Leader, Advanced Research, L’Oréal David Constable, Science Director, ACS Green Chemistry Institute
Thursday, February 23, 2017
Fighting Cancer: Epigenetic Targets for Oncology Session 2 of the 2017 Drug Design and Delivery Symposium
Stuart Conway, Professor of Organic Chemistry, University of Oxford Sharan Bagal, Senior Medicinal Chemist, AstraZeneca
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www.acs.org/acswebinars Slides available now! Recordings are an exclusive ACS member benefit.
“How to Make Chocolate for your Special Valentine: Flowers Bloom, Chocolate Shouldn't”
Contact ACS Webinars at [email protected] ®
Bill Courtney Food Chemist and Grant
Specialist, Washington University
School of Medicine
Rich Hartel Professor of Food Engineering,
University of Wisconsin-Madison
52
“I plan to share this with my Honors students and have them create their own experiment to test collapse time on their favorite ice creams next semester. Thanks for a great webinar!”
Daphne Figueroa, Professor of Chemistry, San Diego Miramar College, San Diego ACS member for 26 years strong!
Be a featured fan on an upcoming webinar! Write to us @ [email protected]
How has ACS Webinars benefited you?
®
Quote in reference to: http://bit.ly/IceCreamChemistry2
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Benefits of ACS Membership
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Upcoming ACS Webinars www.acs.org/acswebinars
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Contact ACS Webinars ® at [email protected]
Thursday, February 16, 2017
Natural, Sustainable Innovation: L’Oréal’s Commitment to Renewable Materials and Eco-Friendly Processes
Michel Philippe, Senior Research Associate and Sustainable Innovation Manager, L’Oréal
Xavier Marat, Group Leader, Advanced Research, L’Oréal David Constable, Science Director, ACS Green Chemistry Institute
Thursday, February 23, 2017
Fighting Cancer: Epigenetic Targets for Oncology Session 2 of the 2017 Drug Design and Delivery Symposium
Stuart Conway, Professor of Organic Chemistry, University of Oxford Sharan Bagal, Senior Medicinal Chemist, AstraZeneca