The Chemistry of Chocolate Fla o Chocolate Flavor

The Chemistry of Chocolate Fla o Chocolate Flavor

The Chemistry of Chocolate Fla o Chocolate Flavor

The Chemistry of The Chemistry of Chocolate Fla o Chocolate Fla o Chocolate Flavor Chocolate Flavor Sheryl Barringer Sheryl Barringer The Ohio State University The Ohio State University The Ohio State University The Ohio State University Columbus OH, USA Columbus OH, USA

The Chemistry of Chocolate Fla o Chocolate Flavor

Cocoa beans come originally Cocoa beans come originally Cocoa beans come originally Cocoa beans come originally from: from:   a) Hawaii a) Hawaii   a) Hawaii a) Hawaii   b) Ivory Coast b) Ivory Coast ) M i ) M i   c) Mexico c) Mexico   d) Switzerland d) Switzerland

The Chemistry of Chocolate Fla o Chocolate Flavor

Cocoa beans come originally Cocoa beans come originally Cocoa beans come originally Cocoa beans come originally from: from:   a) Hawaii a) Hawaii   a) Hawaii a) Hawaii   b) Ivory Coast b) Ivory Coast ) M i ) M i   c) Mexico c) Mexico   d) Switzerland d) Switzerland

The Chemistry of Chocolate Fla o Chocolate Flavor

From 1528 to the 1600’s the From 1528 to the 1600’s the From 1528 to the 1600 s, the From 1528 to the 1600 s, the secret to making chocolate was secret to making chocolate was concealed by the: concealed by the:   a) Dutch a) Dutch   b) French b) French   b) French b) French   c) Spanish c) Spanish d) S i d) S i   d) Swiss d) Swiss

The Chemistry of Chocolate Fla o Chocolate Flavor

From 1528 to the 1600’s the From 1528 to the 1600’s the From 1528 to the 1600 s, the From 1528 to the 1600 s, the secret to making chocolate was secret to making chocolate was concealed by the: concealed by the:   a) Dutch a) Dutch   b) French b) French   b) French b) French   c) Spanish c) Spanish d) S i d) S i   d) Swiss d) Swiss

The Chemistry of Chocolate Fla o Chocolate Flavor

Chocolate became affordable to Chocolate became affordable to h b h b the masses because: the masses because:   a) Breeding produces high yield cocoa a) Breeding produces high yield cocoa   a) Breeding produces high yield cocoa a) Breeding produces high yield cocoa trees trees   b) Sugar cane becomes a cheap source of b) Sugar cane becomes a cheap source of   b) Sugar cane becomes a cheap source of b) Sugar cane becomes a cheap source of sugar sugar ) I ti f th t i k ) I ti f th t i k   c) Invention of the steam engine makes c) Invention of the steam engine makes grinding cheap grinding cheap   d) The king of England declares cocoa to d) The king of England declares cocoa to be tax exempt be tax exempt

The Chemistry of Chocolate Fla o Chocolate Flavor

Chocolate became affordable to Chocolate became affordable to h b h b the masses because: the masses because:   a) Breeding produces high yield cocoa a) Breeding produces high yield cocoa   a) Breeding produces high yield cocoa a) Breeding produces high yield cocoa trees trees   b) Sugar cane becomes a cheap source of b) Sugar cane becomes a cheap source of   b) Sugar cane becomes a cheap source of b) Sugar cane becomes a cheap source of sugar sugar ) I ti f th t i ) I ti f th t i   c) Invention of the steam engine c) Invention of the steam engine makes grinding cheap makes grinding cheap   d) The king of England declares cocoa to d) The king of England declares cocoa to be tax exempt be tax exempt

Milk chocolate was invented in Milk chocolate was invented in b l b l 1876 by Daniel Peter in: 1876 by Daniel Peter in:   a) Holland a) Holland   a) Holland a) Holland   b) France b) France ) S i ) S i   c) Spain c) Spain   d) Switzerland d) Switzerland

Milk chocolate was invented in Milk chocolate was invented in b l b l 1876 by Daniel Peter in: 1876 by Daniel Peter in:   a) Holland a) Holland   a) Holland a) Holland   b) France b) France ) S i ) S i   c) Spain c) Spain   d) Switzerland d) Switzerland

What is flavor? What is flavor? What is flavor? What is flavor?   Flavor = taste + aroma Flavor = taste + aroma   Flavor = taste + aroma Flavor = taste + aroma T t t lt bitt T t t lt bitt i i   Taste = sweet, salty, sour, bitter, Taste = sweet, salty, sour, bitter, umami umami   Aroma = smell = volatiles Aroma = smell = volatiles

Taste + Smell Taste + Smell Taste + Smell Taste + Smell Smell Taste

Complicated aroma Complicated aroma Complicated aroma Complicated aroma   Cherry Cherry – – 1 1   Cherry Cherry 1 1   Chocolate Chocolate – – 200? 200?   47 Hydrocarbons 47 Hydrocarbons   28 Alcohols 28 Alcohols   53 Acids 53 Acids   7 Phenols 7 Phenols   24 24 Aldehydes Aldehydes   41 41 Ketones Ketones   57 Esters 57 Esters   14 14 Pyrrols Pyrrols   9 Pyridines, 9 Pyridines, chinoline chinoline   80 80 Pyrazines Pyrazines, , chinoxalines chinoxalines   21 Nitrogenous compounds 21 Nitrogenous compounds   15 Sulfur compounds 15 Sulfur compounds y y , ,   7 7 Thiazoles Thiazoles   11 11 Oxazoles Oxazoles   34 34 Furanes Furanes pyrones pyrones lactones lactones   34 34 Furanes Furanes, , pyrones pyrones, lactones , lactones Ziegleder and Biehl 1988

Which volatiles are most Which volatiles are most important? important?   Highest concentration Highest concentration   Highest concentration Highest concentration – – But thresholds vary But thresholds vary   CHARM CHARM – –> flavor dilution > flavor dilution h h h h – – Gas Chromatograph Gas Chromatograph – – split detector, detection of odor, dilute, repeat split detector, detection of odor, dilute, repeat

FD≥512 in milk chocolate FD≥512 in milk chocolate FD≥512 in milk chocolate FD≥512 in milk chocolate   Vanillin Vanillin – – vanilla vanilla   3 3- -methylbutanal methylbutanal – – malty malty   2 2- -ethyl ethyl- -3,5 3,5- -dimethylpyrazine dimethylpyrazine – – potato chip potato chip   1 1- -octen octen- -3 3- -one one – – mushroom mushroom   2 2- -ethyl ethyl- -3,6 3,6- -dimethylpyrazine dimethylpyrazine – – nutty nutty   2,3 2,3- -diethyl diethyl- -5 5- -methylpyrazine methylpyrazine – – potato chip potato chip   Z Z- -2 2- -nonenal nonenal – – green green   E,E E,E- -2,4 2,4- -decadienal decadienal – – fatty fatty   E,E E,E- -2,4 2,4- -nonadieanal nonadieanal – – fatty fatty   Delta Delta- -decalactone decalactone – – peach peach   2 2- -methyl methyl- -3 3- -methyldithiofuran methyldithiofuran - - meaty meaty   2 and 3 2 and 3- -methylbutanoic acid methylbutanoic acid – – sweaty sweaty Schnermann and Schieberle, 1997

The following steps are critical The following steps are critical to the best chocolate flavor to the best chocolate flavor (choose all that apply): (choose all that apply): (choose all that apply): (choose all that apply):   a) Choosing the best variety of beans a) Choosing the best variety of beans b) L tti th b t th d f f d b) L tti th b t th d f f d   b) Letting the beans rot on the ground for a few days b) Letting the beans rot on the ground for a few days   c) Sun drying the beans c) Sun drying the beans   d) Roasting the beans d) Roasting the beans   d) Roasting the beans d) Roasting the beans   e) Grinding the beans e) Grinding the beans   f) f) Conching Conching the cocoa liquor (mix for a day) the cocoa liquor (mix for a day) f) f) Conching Conching the cocoa liquor (mix for a day) the cocoa liquor (mix for a day)   g) Tempering the chocolate (heat g) Tempering the chocolate (heat- -cool cycling before cool cycling before molding) molding)

The following steps are critical The following steps are critical to the best chocolate flavor to the best chocolate flavor (choose all that apply): (choose all that apply): (choose all that apply): (choose all that apply):   a) Choosing the best variety of beans a) Choosing the best variety of beans b) L tti th b t th d f f b) L tti th b t th d f f   b) Letting the beans rot on the ground for a few b) Letting the beans rot on the ground for a few days days   c) Sun drying the beans c) Sun drying the beans   c) Sun drying the beans c) Sun drying the beans   d) Roasting the beans d) Roasting the beans   e) Grinding the beans e) Grinding the beans   f) f) Conching Conching the cocoa liquor (mix for a day) the cocoa liquor (mix for a day)   g) Tempering the chocolate (heat g) Tempering the chocolate (heat- -cool cycling before cool cycling before ldi ) ldi ) molding) molding)

Steps in chocolate manufacture Steps in chocolate manufacture h ff h ff that affect aroma that affect aroma   Variety of tree Variety of tree   (Winnowing) (Winnowing)   Variety of tree Variety of tree   Growing location Growing location   Fermentation Fermentation   (Winnowing) (Winnowing)   (Grinding) (Grinding)   Additional ingredients Additional ingredients   Fermentation Fermentation   Drying Drying   Roasting Roasting   Additional ingredients Additional ingredients   Conching Conching   (Tempering) (Tempering)   Roasting Roasting   Alkalinization Alkalinization (opt) (opt)   (Tempering) (Tempering)

Variety of tree Variety of tree Variety of tree Variety of tree   Forestero Forestero (80 (80- -92%) 92%)   Forestero Forestero (80 (80 92%) 92%)   Trinitario Trinitario (5 (5- -10%) 10%)   Criollo Criollo (0 (0- -10%) 10%)   Criollo Criollo (0 (0 10%) 10%)

The majority of today’s cocoa The majority of today’s cocoa b b beans are grown in: beans are grown in:   a) Hawaii a) Hawaii   a) Hawaii a) Hawaii   b) Ivory Coast b) Ivory Coast ) M i ) M i   c) Mexico c) Mexico   d) Switzerland d) Switzerland

The majority of today’s cocoa The majority of today’s cocoa b b beans are grown in: beans are grown in:   a) Hawaii a) Hawaii   a) Hawaii a) Hawaii   b) Ivory Coast b) Ivory Coast ) M i ) M i   c) Mexico c) Mexico   d) Switzerland d) Switzerland

Cacao growing location Cacao growing location Cacao growing location Cacao growing location   Within 10 Within 10° ° of equator of equator o   Country differences i e Country differences i e   Country differences, i.e. Country differences, i.e. Brazil and Africa = base bean Brazil and Africa = base bean Ecuador Venezuela Ecuador Venezuela Trinidad Sri Lanka Trinidad Sri Lanka Ecuador, Venezuela, Ecuador, Venezuela, Trinidad, Sri Lanka Trinidad, Sri Lanka = aromatic or flavor bean = aromatic or flavor bean

Fermentation Fermentation Fermentation Fermentation   Succession of bacteria Succession of bacteria   Succession of bacteria Succession of bacteria   3 3- -5 days 5 days

Generation of aroma precursors Generation of aroma precursors Generation of aroma precursors Generation of aroma precursors   Succession of bacteria: Succession of bacteria:   Succession of bacteria: Succession of bacteria:   Yeast Yeast - -> Lactic acid bacteria > Lactic acid bacteria - -> acetic acid > acetic acid bacteria bacteria > spore formers > spore formers > mold > mold bacteria bacteria - -> spore formers > spore formers - -> mold > mold   Enzymes Enzymes   Source of volatiles: reducing sugars, free Source of volatiles: reducing sugars, free g g , g g , amino acids and amino acids and oligopeptides oligopeptides

Gelatinous coating Gelatinous coating Gelatinous coating Gelatinous coating   Sugars Sugars   Sugars Sugars   Pectin Pectin - -> semi > semi- -anaerobic anaerobic – – encourages encourages yeast yeast yeast yeast   citric acid citric acid - -> pH 3.6 > pH 3.6 – – encourages yeast encourages yeast

Yeasts Yeasts Yeasts Yeasts   Sucrose glucose fructose to ethanol and Sucrose glucose fructose to ethanol and   Sucrose, glucose, fructose to ethanol and Sucrose, glucose, fructose to ethanol and CO CO2 2   Pectinolytic Pectinolytic enzymes enzymes break down pectin break down pectin   Pectinolytic Pectinolytic enzymes enzymes – – break down pectin break down pectin “ “sweatings sweatings” ” M t b li it i id M t b li it i id H i H i   Metabolize citric acid Metabolize citric acid – – pH rises pH rises   Produce acetic, oxalic, phosphoric, Produce acetic, oxalic, phosphoric, succinic succinic, , malic malic acids acids – – buffers pH buffers pH

Lactic acid bacteria Lactic acid bacteria Lactic acid bacteria Lactic acid bacteria   Glucose to lactic acid Glucose to lactic acid   Glucose to lactic acid Glucose to lactic acid (or ethanol, acetic acid, glycerol, (or ethanol, acetic acid, glycerol, mannitol mannitol) )   Produce citric acid then consume it Produce citric acid then consume it   Aeration and temperature increase Aeration and temperature increase   Aeration and temperature increase Aeration and temperature increase

Acetic acid bacteria Acetic acid bacteria Acetic acid bacteria Acetic acid bacteria   Decrease ethanol and lactic acid Decrease ethanol and lactic acid   Decrease ethanol and lactic acid Decrease ethanol and lactic acid   Oxidize ethanol to acetic acid to carbon Oxidize ethanol to acetic acid to carbon dioxide and water dioxide and water dioxide and water dioxide and water   Sugars to acetic acid Sugars to acetic acid   Increase in acetic acid Increase in acetic acid – – kills seeds kills seeds   Hydrolyze proteins Hydrolyze proteins y y p y y p   Temperature rises to 122 F Temperature rises to 122 F

Assorted spore forming bacteria, Assorted spore forming bacteria, ill ill esp esp Bacillus Bacillus   pH 5 0 pH 5 0   pH 5.0 pH 5.0 M ld f i M ld f i ff fl ff fl   Mold, fungi Mold, fungi – – off flavors off flavors

Enzymes in beans Enzymes in beans Enzymes in beans Enzymes in beans   Polyphenoloxidase: oxidizes bitter Polyphenoloxidase: oxidizes bitter   Polyphenoloxidase: oxidizes bitter Polyphenoloxidase: oxidizes bitter polyphenols polyphenols   Two proteases: aspartic Two proteases: aspartic endopeptidase endopeptidase   Two proteases: aspartic Two proteases: aspartic endopeptidase endopeptidase and serine and serine carboxy carboxy- -( (exo exo)peptidase on )peptidase on vicilin vicilin (7S) (7S) class globulin storage proteins class globulin storage proteins vicilin vicilin (7S) (7S)- -class globulin storage proteins class globulin storage proteins   Roasting these peptides with reducing Roasting these peptides with reducing d h l t d h l t sugars produces chocolate aroma sugars produces chocolate aroma   No aroma yet No aroma yet

Drying Drying Drying Drying   Stop fermentation Stop fermentation   Stop fermentation Stop fermentation Off fl Off fl   Off flavors: Off flavors:   Smoke, from wood fires Smoke, from wood fires   Hammy, from short chain Hammy, from short chain fatty acids by bacilli and fatty acids by bacilli and y y y y fungi fungi

Roasting Roasting Roasting Roasting   No No cystine cystine nor nor cysteine cysteine is present and is present and   No No cystine cystine nor nor cysteine cysteine is present, and is present, and methionine methionine at low concentration at low concentration   Maillard Maillard reaction, reaction, especially especially Strecker Strecker especially especially Strecker Strecker degradation degradation   Reducing sugars are the Reducing sugars are the   Reducing sugars are the Reducing sugars are the limiting factor limiting factor

Simplified Simplified Maillard Maillard reaction ( reaction (pyrazines pyrazines and and ld h d ld h d ) ) aldehydes aldehydes) ) Aldose Sugar + Amino compound Aldose Sugar + Amino compound N-substituted glycosylamine + H2O High T I Amadori rearrangment product (ARP) 1-amino-1-deoxy-2-ketose pH>7 pH>7 pH≤7 Reductones Fission products (acetol, diacetyl, pyruvaldehyde, etc) Schiff base of hydroxymethyfurfural (HMF) or furfural Dehydroreductones + amino S k d d i - amino compound + H2O + amino II Aldimines HMF or furfural Aldehydes + amino compound + amino compound Strecker degradation compound + amino compound III (pyrazines, pyradines, pyrroles)  Alkali conditions favor the formation of alkylpyrazines and Strecker aldehydes

Volatiles present: Volatiles present: Volatiles present: Volatiles present:   Pyrazines Pyrazines – – roasted notes roasted notes   Pyrazines Pyrazines roasted notes roasted notes   Aldehydes Aldehydes Al h l Al h l   Alcohols Alcohols   Esters Esters - - flowery, green flowery, green

Tetramethylpyrazine Tetramethylpyrazine Tetramethylpyrazine Tetramethylpyrazine   90% of pyrazines in chocolate 90% of pyrazines in chocolate   90% of pyrazines in chocolate 90% of pyrazines in chocolate   Nutty, grassy, pungent, persistent Nutty, grassy, pungent, persistent chocolate note chocolate note chocolate note chocolate note   Maillard Maillard reaction reaction

Tetramethylpyrazine formation Tetramethylpyrazine formation Tetramethylpyrazine formation Tetramethylpyrazine formation 7 8 170 C 160 C 5 6 (mg/kg) 150 C 140 C 130 C 120 C 4 5 ylpyrazine 2 3 Tetramethy Adapted from Adapted from 1 Adapted from Adapted from Ramli Ramli et al. 2006 et al. 2006 20 30 40 50 Roasting Time, min

The “Dutch process” involves The “Dutch process” involves ki th b i lk li ki th b i lk li soaking the beans in alkali, soaking the beans in alkali, making the chocolate (choose making the chocolate (choose making the chocolate (choose making the chocolate (choose all that apply): all that apply): ) T t ) T t   a) Taste sour a) Taste sour   b) Taste less bitter b) Taste less bitter   c) Have a fuller, rounder flavor c) Have a fuller, rounder flavor   d) Dissolve in water d) Dissolve in water   d) Dissolve in water d) Dissolve in water   e) Turn brown e) Turn brown

The “Dutch process” involves The “Dutch process” involves ki th b i lk li ki th b i lk li soaking the beans in alkali, soaking the beans in alkali, making the chocolate (choose making the chocolate (choose making the chocolate (choose making the chocolate (choose all that apply): all that apply): ) T t ) T t   a) Taste sour a) Taste sour   b) Taste less bitter b) Taste less bitter   c) Have a fuller, rounder flavor c) Have a fuller, rounder flavor   d) Dissolve in water d) Dissolve in water   d) Dissolve in water d) Dissolve in water   e) Turn brown e) Turn brown

Alkalinization Alkalinization Alkalinization Alkalinization   Make cocoa powder (hot chocolate) Make cocoa powder (hot chocolate)   Make cocoa powder (hot chocolate) Make cocoa powder (hot chocolate)   Water soluble Water soluble   Water soluble Water soluble   Darker Darker   Changes flavor Changes flavor   Changes flavor Changes flavor pH 5 pH 5  - - -   pH 8 pH 8

Effect of Effect of alkalinization alkalinization on on pyrazines pyrazines 120000 Di th l i 100000 PB) Dimethyl pyrazines Trimethyl pyrazine Tetramethyl pyrazine 60000 80000 tration (P 2,3-diethyl 5-methyl pyrazine 20000 40000 Concent 5.2 5.7 6.2 6.7 7.2 7.7 pH

Little effect on aroma: Little effect on aroma: Little effect on aroma: Little effect on aroma:   Winnow (remove shells) Winnow (remove shells)   Winnow (remove shells) Winnow (remove shells)   Grind to liquor Grind to liquor

The three most common The three most common ingredients, by weight, mixed to ingredients, by weight, mixed to make dark chocolate are: make dark chocolate are: make dark chocolate are: make dark chocolate are:   a) Caffeine a) Caffeine   e) Salt e) Salt ) )   b) Cocoa liquor b) Cocoa liquor   c) Cocoa butter c) Cocoa butter ) )   f) Sugar f) Sugar   g) Vegetable oil g) Vegetable oil   c) Cocoa butter c) Cocoa butter   d) Lecithin d) Lecithin   g) Vegetable oil g) Vegetable oil   h) Vanilla h) Vanilla

The three most common The three most common ingredients, by weight, mixed to ingredients, by weight, mixed to make dark chocolate are: make dark chocolate are: make dark chocolate are: make dark chocolate are:   a) Caffeine a) Caffeine   e) Salt e) Salt ) )   b) Cocoa liquor b) Cocoa liquor   c) Cocoa butter c) Cocoa butter ) )   f) Sugar f) Sugar   g) Vegetable oil g) Vegetable oil   c) Cocoa butter c) Cocoa butter   d) Lecithin d) Lecithin   g) Vegetable oil g) Vegetable oil   h) Vanilla h) Vanilla

Dark chocolate typically is about Dark chocolate typically is about ( f h l ) ( f h l ) (one from each column): (one from each column):   a) ¼ sugar a) ¼ sugar   e) ¼ fat e) ¼ fat   a) ¼ sugar a) ¼ sugar   b) 1/3 sugar b) 1/3 sugar   c) ½ sugar c) ½ sugar   e) ¼ fat e) ¼ fat   f) 1/3 fat f) 1/3 fat   g) ½ fat g) ½ fat   c) ½ sugar c) ½ sugar   d) ¾ sugar d) ¾ sugar   g) ½ fat g) ½ fat   h) ¾ fat h) ¾ fat

Dark chocolate typically is about Dark chocolate typically is about ( f h l ) ( f h l ) (one from each column): (one from each column):   a) ¼ sugar a) ¼ sugar   e) ¼ fat e) ¼ fat   a) ¼ sugar a) ¼ sugar   b) 1/3 sugar b) 1/3 sugar   c) ½ sugar c) ½ sugar   e) ¼ fat e) ¼ fat   f) 1/3 fat f) 1/3 fat   g) ½ fat g) ½ fat   c) ½ sugar c) ½ sugar   d) ¾ sugar d) ¾ sugar   g) ½ fat g) ½ fat   h) ¾ fat h) ¾ fat

Milk chocolate typically is about Milk chocolate typically is about ( f h l ) ( f h l ) (one from each column): (one from each column):   a) ¼ sugar a) ¼ sugar   e) ¼ fat e) ¼ fat   a) ¼ sugar a) ¼ sugar   b) 1/3 sugar b) 1/3 sugar   c) ½ sugar c) ½ sugar   e) ¼ fat e) ¼ fat   f) 1/3 fat f) 1/3 fat   g) ½ fat g) ½ fat   c) ½ sugar c) ½ sugar   d) ¾ sugar d) ¾ sugar   g) ½ fat g) ½ fat   h) ¾ fat h) ¾ fat

Milk chocolate typically is about Milk chocolate typically is about ( f h l ) ( f h l ) (one from each column): (one from each column):   a) ¼ sugar a) ¼ sugar   e) ¼ fat e) ¼ fat   a) ¼ sugar a) ¼ sugar   b) 1/3 sugar b) 1/3 sugar   c) ½ sugar c) ½ sugar   e) ¼ fat e) ¼ fat   f) 1/3 fat f) 1/3 fat   g) ½ fat g) ½ fat   c) ½ sugar c) ½ sugar   d) ¾ sugar d) ¾ sugar   g) ½ fat g) ½ fat   h) ¾ fat h) ¾ fat

Addition of ingredients Addition of ingredients Addition of ingredients Addition of ingredients   Vanilla Vanilla – – vanillin vanillin   Vanilla Vanilla vanillin vanillin   Sugar Sugar   Cocoa butter Cocoa butter   Cocoa butter Cocoa butter   Lecithin Lecithin   Milk Milk > caramel milky “sour” > caramel milky “sour”   Milk Milk - -> caramel, milky, sour > caramel, milky, sour

Dark Chocolate vs. Milk Chocolate Dark Chocolate vs. Milk Chocolate Ald h d Ald h d Aldehydes Aldehydes  40% cocoa mass, 10% cocoa butter, sugar & milk varied S i t i d l til 1600 ) Dark Milk  Sugar increases, protein decreases volatiles 600 800 1000 1200 1400 ntration (ppb) 200 400 600 Concen

Conching Conching Conching Conching   24 hours of mixing 24 hours of mixing   24 hours of mixing 24 hours of mixing   Lose ½ to ¾ of all Lose ½ to ¾ of all volatiles volatiles volatiles volatiles – – Methanol Methanol – – Acetic acid Acetic acid   Noticeable change in Noticeable change in odor odor – – No preference No preference

Changes during Changes during conching conching Changes during Changes during conching conching 160000 methanol 120000 140000 acetic acid 3-methylbutanal hexane 2-methylbutanal 2 3 b di 80000 100000 (ppb) 2,3-butanedione ethyl acetate acetaldehyde isobutanoic acid l 20000 40000 60000 conc nonanal benzaldehyde furfuryl pyrrole {SB} 2-methylpropanal acetone 20000 0 5 10 15 20 25 30 35 40 45 50 Time (hour) acetone tetradecane methional benzyl alcohol 2 nonanone 2-nonanone

Old chocolate will develop white Old chocolate will develop white bl d b bl d b spots, or bloom, caused by: spots, or bloom, caused by:   a) Drying out a) Drying out   a) Drying out a) Drying out   b) Fading b) Fading ) F t ) F t t lli i t lli i   c) Fat c) Fat recrystallizing recrystallizing   d) Mold growth d) Mold growth

Old chocolate will develop white Old chocolate will develop white bl d b bl d b spots, or bloom, caused by: spots, or bloom, caused by:   a) Drying out a) Drying out   a) Drying out a) Drying out   b) Fading b) Fading ) F t ) F t t lli i t lli i   c) Fat c) Fat recrystallizing recrystallizing   d) Mold growth d) Mold growth

Tempering Tempering Tempering Tempering   Texture Texture   Texture Texture – – Heat, cool, heat, cool Heat, cool, heat, cool

Conclusion Conclusion Conclusion Conclusion   Variety of tree Variety of tree   (Winnowing) (Winnowing)   Variety of tree Variety of tree   Growing location Growing location   Fermentation Fermentation   (Winnowing) (Winnowing)   (Grinding) (Grinding)   Additional ingredients Additional ingredients   Fermentation Fermentation   Drying Drying   Roasting Roasting   Additional ingredients Additional ingredients   Conching Conching   (Tempering) (Tempering)   Roasting Roasting   Alkalinization Alkalinization (opt) (opt)   (Tempering) (Tempering)

Chocolate is considered an Chocolate is considered an h d b h d b aphrodisiac because: aphrodisiac because:   a) Montezuma II was known for the size a) Montezuma II was known for the size   a) Montezuma II was known for the size a) Montezuma II was known for the size of his harem of his harem   b) Casanova ate large amounts of b) Casanova ate large amounts of   b) Casanova ate large amounts of b) Casanova ate large amounts of chocolate chocolate ) Th Bi h f Chi M i f b d ) Th Bi h f Chi M i f b d   c) The Bishop of Chiapas, Mexico forbade c) The Bishop of Chiapas, Mexico forbade the drinking of chocolate the drinking of chocolate   d) Serotonin and d) Serotonin and phenylethylamine phenylethylamine in in chocolate produce a feeling like falling in chocolate produce a feeling like falling in love love

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