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Transcript of Chocolate
Who? What? Where? When?
Mayan 600 - 1000 AD
Many Mayan drawings show cacao pods being used in rituals and ceremonies.
The writings also describe multiple ways of preparing the cacao.
Drinks of varying consistencies from thin liquid to a thick paste are made.
Use of different flavorings: spice, vanilla, cinnamon, honey.
Beans are local and international currency.
turkey = 200 beans
tomato = 3 beans
The Mayan begin to trade with other tribes in Mexico as well as what becomes south west United States.
In 900 AD the Mayan civilization finds its demise.
Aztec 1200 - 1519 AD
1325, the Aztecs conquer the Toltecs.
They discovered the bean of worship and drink and name it cacahuatl.
The beans are primarily used as currency and drink.
The beans are the only currency accepted for taxes levied by the Aztec rulers.
The beans are thought to be medicinal, aphrodisiac, and strengthening for warriors.
Cacao is used as war rations.
The Europeans: 1502-1900s
Africa: 1800s - Today
Africa: Introduction of Cacao
African Family Farming is Better
Chocolate Industry Today
What is Fermentation?
Importance to Taste
Chemical Nature of Taste
Fermentation lasts about 3-7 days
Fermentation = Flavor
The Modern Chocolate Industry
Billion Dollar Industry
Fair Trade Chocolate
Yeasts 0-2 Days
Aerobic Spore-Forming Bacteria
Now We Feast!
MesoAmerica 1800 BCE- 1528 AD
Olmec 1800 BCE- 400 BCE
“Cultura Madre” of Central America.
Flourished between 1200- 400 BCE; Formative period.
Traces of Olmec civilization can be found at sites on the southern coast of The Gulf of Mexico, Veracruz.
System of writing, but only a few inscriptions exist today. Knowledge of the Olmecs is dependent on archeological evidence.
Were the first known to process and eat cacao beans.
Residue left in a small bowl in 1800 BCE at Paso de la Amada in South Chiapas, Mexico, provides the earliest evidence of cacao use.
Olmecs figured out how to eat cacao: fermenting, drying, roasting and grinding.
This took some knowledge of food science and biochemistry.
This process is still the basis of today’s chocolate production.
Olmecs and Cacao - 1800 BCE
Olmecs were a sophisticated society, they had considerable influence on later cultures such as the Mayan and Aztec.
They passed their knowledge of cacao, “xocoatl” down to the Mayans.
In 400-300 BCE the Olmecs disappear.
Olmecs to Mayans - Passing the Pod
300 BCE - 500 AD
The Mayans resided in the southern part of Mexico, Yucatan Peninsula.
The plants had ideal growing conditions in this region and flourished.
The Mayans worshiped the sacred tree and named it cacahuaquchtl.
They believed that the pods were a gift to man from the gods.
Consumption of the cacao bean is restricted to the Mayan society’s elite.
Chocolate has enjoyed a long history aside multiple cultures and civilizations.
The earliest evidence of chocolate use and consumption dates back to 1800 BCE
By the end of the 8th century chocolate was being imported thousands of kilometers across regions
High demand for chocolate has resulted in conflict and bloodshed. Slavery, human trafficking, and child labor color both the history and current state of chocolate production
Theobroma cacao: food of the gods
1502: Columbus brings Cocoa beans back to Spain
Columbus referred to the beans as almonds and noted their use as a currency for the local people.
When he brought the drink back to Spain he did not add any sweeteners and the Spanish court did not take notice to the new commodity
1528: Cortez markets the potential in chocolate
As Cortez returns to Europe he plants cocoa along the way
When presenting chocolate to the royal court he wisely sweetens and flavors the drink with sugar, cinnamon, and vanilla
The sweetened chocolate instantly catches on with the Spanish aristocracy, so much so that they attempt to keep chocolate production a secret
This begins Spain's 80 year long control over European chocolate
1600s: Chocolate spreads across Europe
Other European nations build cocoa plantations across their colonies
Pope Pius V declares chocolate to be permitted during lent, the popularity of chocolate drinks soars with the elite and the clergy
1828: Cocoa press invented
Coenraad Johannes van Houten invents machine that removes fat from cocoa beans and grinds pressed beans into fine powder. The powder is then treated with alkaline salts to make it more soluble in water
1879: Milk chocolate invented
Daniel Peter and Henri Nestlé team up to invent a milder chocolate using powdered milk
1847: First solid chocolate bar
Created by melting cocoa fats, cocoa powder, and sugar together before molding into a shape to harden.
A wild success!
1900s: Chocolate becomes an industry
Various companies are founded to market and produce the new array of chocolate treats
1906 - first brownie recipe
1912 - filled chocolates
1920s - individual chocolate bars
Many of these companies saw chocolate as an alternative to alcohol
Step 1: Harvest Beans
Cocoa pods are manually harvested
Ripe pods are orange in color, immature pods are green.
Pods are carried to a processing area where they are gently split open to remove the beans
Each pod holds about 40 beans
Step 2: Fermentation
Beans are allowed to ferment in large trays or in heaps covered by banana leaves
Beans are periodically stirred to prevent uneven fermentation
This process takes about 3-7 days
Holidays & Special Occasions
Step 3: Drying the beans
Once the beans have been fermented they are spread out to sun dry
This process takes about a week
The weight of the beans will be reduced by half
The beans will then be ready for shipping
Step 4: Grinding the beans
This is a multistep process
First the beans are roasted and winnowed
Winnowing is the removal of the nibs, or meaty innards, from the shell
The nibs are then ground to separate out the chocolate liquor, or cocoa fats
This works by melting the fats via heat, allowing the liquid to be removed
Step 5: Processing the cocoa into chocolate
Cocoa powder is now combined with ingredients to form a final product
White - cocoa butter, cocoa liquor, sugar, vanilla, lecithin
Milk - milk powder, cocoa powder, cocoa butter, cocoa liquor, sugar, vanilla, lecithin
Dark - cocoa powder, cocoa butter, cocoa liquor, sugar, vanilla, lecithin
During this time we see a succession of microbes.
Each with their own individual roles in building the flavor and aroma of chocolate
The Lactic Acid Bacteria
are the two major players in this group of microbes.
is present at the start of fermentation but its population will decline as the fermentation continues.
Gram positive rod
Can tolerate pH as low as 3.2
Can utilize a variety of carbon sources
Used as a probiotic
Has a role in a variety of food productions ranging from meats, dairy products, and plant products
is the major lactic acid bacteria in cocoa fermentation and is present throughout the lactic acid stage
Gram positive rod
Acid and ethanol tolerant
Can ferment fructose, producing mannitol
occurs naturally on the cocoa pods, resulting in spontaneous inoculation
The Lactic Acid Bacteria (LAB) arise due to environmental changes in the cocoa heaps
As yeast fermentation continues, the cocoa heap will become hotter, more acidic, and more anaerobic
The LAB can tolerate these conditions and will end up out competing other microbes
This means that because the LAB will grow better, they will begin to dominate the population
As the LAB grow they will be fermenting glucose, fructose, and citrate into lactic acid, acetic acid, ethanol, and mannitol
Mannitol production occurs in the later stages of cocoa bean fermentation
The switch from producing lactic acid to mannitol aids in flavor development
Lactic acid is nonvolatile, and is retained in the beans
Mannitol can be used by other microbes later on to produce volatile acids
The LAB period will end as the oxygen concentration begins to increase and pH decreases
As these reactions occur the temperature of the heap is steadily rising and the pulp surrounding the beans is breaking down, resulting in more oxygen availability
The change in environmental conditions will begin to favor the next group of microbes, who will carry on the fermentation process
Glucose, Fructose, Citrate --------------> Lactic Acid, Acetic Acid, Ethanol, Mannitol
The Acetic Acid Bacteria
The region that the cocoa originated determines which of the species within this group are present
The dominant species across most regions, however, is
appears as oxygen concentrations increase and persists throughout the remainder of fermentation
Gram negative ovoids
Is found naturally on tropical plants, thus inoculation occurs spontaneously
Ethanol and acid tolerant
Can actively degrade the pectin of cocoa pulp to increase oxygen availability
Uses oxygen to boost metabolism and growth
Outside of cocoa fermentation this bacterium is used in production of vinegar and kombucha, making use of some of the same reactions in cocoa fermentation
This bacterium also has a less marvelous side as a major cause of spoilage in wine and beer.
Louis Pasteur, one of the great forefathers of microbiology, invented the process of pasteurization while attempting to solve the problem of beer and wine spoilage.
Mayans and Cacao
From the seeds of the cacoa tree,
Latin for "Food of The Gods"
Theos - gods
Broma - food
Native to Latin America
Transported to West Africa
In 2010, Switzerland led, at 22 pounds per person.
Austria and Ireland followed at 20 pounds and 19 pounds.
The United States comes in at 11th place, with Americans gobbling nearly 12 pounds apiece each year.
Toltec Folklore 900 AD
The Toltecs occupied the same regions as the Mayans, in the Yucatan.
King Quetzalcoatl, fled due to political unrest. Sailed away, but vowed to return.
Legend states that Quetzalcoatl is actually a God, and in 1519 he would return as a white faced king to free his people.
The legend survives and becomes part of Aztec lore.
Aztec 1200 -1519 AD
Montezuma, the ninth Aztec emperor, was said to drink 50 cups of xocoatl a day often before going to his harem.
In 1517, Hernan Cortez arrives in Mexico. Because of his white face he is believed to be King Quetzalcoatl.
In 1519, Cortez had conquered Montezuma’s entire kingdom; Montezuma realizes when it is too late that Cortez is not King Quetzalcoat.
Cortez gains possession of an enormous store of cacahuatl worth an emperor’s ransom.
In 1528 Cortez returns to Spain with the beans.
Cortez and Montezuma 1517 - 1528 AD
Under fermented beans have an astringent and bitter taste due partly to polyphenols.
Over fermentation leads to a rise in some bacteria and fungi that can cause off flavors.
Chocolate has over 1500 compounds that contribute to the flavor and aroma.
Due to different growing regions and variation in microbes, flavors vary.
Chocolate flavor chemistry is very complex and is determined both by the cocoa plant variety and the fermentation and roasting process.
The process of flavor is not fully understood.
The Fermentative Contribution of the Lactic Acid Bacteria
The acetic acid produced by these microbes has two roles
A portion of the acid will volatilize, or evaporate
The other portion will penetrate the shell of the bean, reaching the see embryo and aiding in its death
This is important because it stops the cocoa bean from germinating, which can ruin the flavor
grows on the ethanol, mannitol, and lactate left over from the fermentations of the yeasts and LAB.
As it grows, it oxidizes these chemicals into acetic acid.
can even overoxidize acetic acid into carbon dioxide and water.
Oxidation is the process by which electrons are removed
Overoxidation is the additional oxidation of a substrate
The Fermentative Contribution of the Acetic Acid Bacteria
ethanol, mannitol, lactate -----------> acetic acid -------> carbon dioxide, water
By this point the fermentation of the cocoa beans is in its final stages.
Free amino acids are now building up and polyphenols and oligopeptides are forming within the bean due to enzymatic activity following the bean's death
All about Chocolate -- History. (2002, September). Retrieved from http://www.xocoatl.org/history.htm
Amano. (2013, October 23). Cocoa Fermentation | Amano Chocolate. Retrieved from http://www.amanochocolate.com/blog/cocoa-fermentation-all-about-it-part1/
Beckett, S. T. (2000). The science of chocolate (2nd ed.). Cambridge, UK: Royal Society of Chemistry.
Camu, N., De Winter, T., Verbrugghe, K., Cleenwerck, I., Vandamme, P., Takrama, J. S., . . . De Vuyst, L. (2007). Dynamics and biodiversity of populations of lactic acid bacteria and acetic acid bacteria involved in spontaneous heap fermentation of cocoa beans in Ghana. Appl. Environ. Microbiol, 73(6), 1809-1824. doi:10.1128/AEM.02189-06
Camu, N., Winter, T. D., Addo, S. K., Takrama, J. S., Bernaert, H., & Vuyst, L. D. (2008). Fermentation of cocoa beans: influence of microbial activities and polyphenol concentrations on the flavour of chocolate. Journal of The Science of Food and Agriculture, 88, 2288-2297. doi:10.1002/jsfa.3349
Chocolate and Slavery. (n.d.). Retrieved from http://www1.american.edu/ted/chocolate-slave.htm
Earliest Evidence of Chocolate in North America | Science/AAAS | News [Web log post]. (n.d.). Retrieved from http://news.sciencemag.org/2013/01/earliest-evidence-chocolate-north-america
Global Witness (Organization). (2007). Hot chocolate: How cocoa fuelled the conflict in Côte d'Ivoire : a report. Retrieved from Global Witness Publishing website: https://www.globalwitness.org/sites/default/files/pdfs/cotedivoire.pdf
Illeghems, K., De Vuyst, L., & Weckx, S. (2013). Complete genome sequence and comparative analysis of Acetobacter pasteurianus 386B, a strain well-adapted to the cocoa bean fermentation ecosystem. BMC Genomics, 14(526). doi:10.1186/1471-2164-14-526
Kleerebezem, M., Boekhorst, J., Kranenburg, R. V., Molenaar, D., Kuipers, O. P., Leer, R., . . . Siezen, R. J. (2003). Complete genome sequence of Lactobacillus plantarum WCFS1. Proceedings of The National Academy of Sciences, 100(4), 1990-1995. doi:10.1073/pnas.0337704100
Szogyi, A., & Hofstra University. (1997). Chocolate: Food of the gods. Westport, CT: Greenwood Press.
The Chocolate Review. (2007). The Chocolate Review | The History of Chocolate | Chocolate, Beans, Cacao, Cocoa, Were - The Chocolate Review. Retrieved from http://thechocolatereview.com/history-of-chocolate/the-history-of-chocolate.html
The Nibble. (2005). History of Chocolate Timeline - Origin of Chocolate. Retrieved from http://www.thenibble.com/reviews/main/chocolate/the-history-of-chocolate.asp
The Cup of Chocolate
Van Houten's Cocoa ad in The Magazine of American History, Vol. 27, 1892.
Studies have identified isolates of the genera Candida, Pichia, Saccharomyces, Kloeckera, Trichosporon and Schizosaccharomyce, to name a few.
Different species of yeast genera are found in different regions.
It is difficult to determine whether the different yeast flora were due to geography or fermentation practice.
The most common species that have been isolated are Saccharomyce cerevisiae, Candida rugosa, and Kluyveromyces spp.
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Cocoa Beans Drying in Sun South of Kumba by TravelPod Member Modernnomad67 via http://tripwow.tripadvisor.com/
In the Dominican Republic, chocolate drinks are used to treat many kinds of illness, from sore throats to anemia to gastrointestinal illnesses to overworked brains
Transplanted to West Africa between 1822-24 by the Portuguese
First successful cocoa production in the 1880s in São Tomé & Principe islands
Used slave labor
Smallholder farming makes cacao a success
Cacao mixes well with other crops
Ghana benefits from family labor
Single celled fungi that reproduce by budding or fission.
Most common yeast found in fermentation due to its ethanol tolerance.
Can survive the fermentation process.
Côte d’Ivoire's warm & moist climate is ideal for cacoa trees
Produces almost half of the world's cocoa
Conflict over child labor & human trafficking
Present up until the end of fermentation at temperatures of 50 degrees celsius.
Increased in numbers after 24 hrs.
Found when the fermenting mass was approximately 50 degrees celsius.
Grew slowly at the outset of fermentation and then declined gradually.
Roles of Yeast
Break down of citric acid.
Production of organic acids.
Production of volatiles.
Production of pectinolytic enzymes.
The sugar-rich, acidic pulp is ideal for rapid yeast growth.
Conversion of sucrose, glucose and fructose to ethanol and CO2.
Ethanol penetrates the cotyledons of the bean, however the acetic acid kills the beans.
Breakdown of Citric Acid
Some yeast, such as Candida spp. and Pichia spp. metabolize citric acid causing the pH value to increase in the pulp.
The loss of citric acid in the "sweatings," and the microbial metabolism causes an alkaline drift in pH.
Drift in pH along with increasing alcohol levels and aeration, inhibits yeast and their activity decreases as a result.
The chocolate industry is worth an estimated $110 billion a year
The Hershey Company lead all significant public and private programs in the cocoa sector in West Africa
Production of Organic Acids
Several yeast isolates produce organic acids including acetic, oxalic, phosphoric, succinic and malic acids.
These weak organic acids will have a buffering capacity and reduce fluctuations in pH.
Production of Volatiles
ATP producing pathway for the cell
Works with glycolysis when oxygen is not available
Not as efficient but helpful
Yeasts produce a large array of aroma compounds.
Fusel alcohols, fatty acids and fatty acid esters.
Different species produce different aromas.
S. cerevisiae produce large amounts of aoma compounds. These strains form elaborate aroma and flavor characteristics.
Cacao Bean Fermentation
Sucrose within the pulp surrounding the seeds/beans is placed under anaerobic conditions
Temperature reach between 80ºF to 90ºF (32ºC – 38ºC)
Promotes the activity of yeasts, ie: S. cerevisiae & yeast isolates found on the surface of cacao pods
Reduces sucrose to ethanol & carbon dioxide
Bacteria dominate next phase, an aerobic step
Oxidize alcohol into non-volatile lactic acid then acetic acid
The acids start the process of slowly penetrating the beans
Breaking down their cell walls that allow enzymes access to proteins
They are “chewed” into constituent peptides & amino acids to soften the polyphenols
Oxidation by the enzyme polyphenol oxidase, causes a browning of cocoa beans that give chocolate its characteristic color
Production of Pectinolytic Enzymes
Some strains form pectinolytic enzymes. These break down the cement between the walls of the pulp cells. The "cacao honey," drains away as "sweatings."
Formation of void spaces allows air to percolate.
Only four of the yeast species show pectionlytic activity (K. marxianus, S. cerevisiae, C. rugopelliculosa, and K. thermotolerans).
The enzymatic activity is crucial during the first 24 hours, because it breaks down the pulp and allows penetration of oxygen into the fermenting cocoa mass enabling aerobic acetic acid bacteria to grow.
During Late Stages of Fermentation
Increases in the cocoa pulp
pH 3.5 to 5.0
Temperature to 45C
Spore-forming bacteria develop
Producing several chemical compounds that contribute to the acidity
C3 - C5 free fatty acids produced may cause an "off" flavor
Not very important to the process ... as far as they know now
Found in well-aerated parts of the fermenting mass
Thought to cause hydrolysis of the pulp & testa
Produces acids which cause "off" flavor
Ochratoxin A (OTA) is the main mycotoxin
Affecting cocoa integrity
Acid produced in the pulp penetrates & beans
Triggers very complex biochemical reactions that create many of the cocoa flavor precursors
Also strongly reduces the concentration of other chemical compounds
Different cultivaters & growth conditions along with fermenting is arguably the most important part of how chocolate develops certain flavors