Food Flavor

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Food Flavor

• Chapter 11 in your textbook

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Flavor Chemistry Flavor is a combination of
taste and aroma Taste - sweet, sour, bitter,
salty - only what can be sensed on the tongue -
nerve sensations for metallic and
astringent Aroma - volatiles are released in
mouth and then sensed in the nasal cavity
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Food flavors Mixtures of natural and/or
artificial aromatic compounds designed to impart
a flavor, modify a flavor, or mask an
undesirable flavor Natural versus
Artificial Natural - concentrated flavoring
constituents derived from plant or animal
sources Artificial - substances used to impart
flavor that are not derived from plant or animal
sources
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• Most natural flavors are concentrated from
  botanicals
• plants, trees, fruits, and vegetables
• Most artificial flavors are synthesized with high
  purity
• - pharmaceutical flavors

Isolation techniques - Steam distillation - mint
and herbal oils - Solvent extraction - vanilla
oleoresins - Expression - citrus oils -
Supercritical fluid extraction targeted
extractions
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Natural flavors can also be enzymatically or
chemically produced - Fermentation reactions -
Microbial enzymes Saccharomyces
Sp. Lactobacillus Sp. Bacillus Sp. Molds
Maillard flavor compounds Glucose
Glutamic acid chicken Glucose
Lysine burnt or fried potato Glucose
Methionine cabbage Glucose
Phenylalanine caramel Fructose
Glutamic acid chicken Fructose
Lysine fried potato Fructose
Methionine bean soup Fructose
Phenylalanine wet dog
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Artificial Flavors Typically are esters Esters
have pleasant fruity aromas, derived from
acids a condensation reaction ACID
ALCOHOL --gt ESTER WATER Most
artificial flavors are simple mixtures of
esters i.e. Isobutyl formate isobutyl
acetate raspberry
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FERMENTATION and FLAVOR O O
Diacetyl (CH3 C - C CH3 ) is a compound
produced by Yeasts via fermentation of
carbohydrates Major compound in the flavor of
cultured dairy products Butter and butter-like
flavor
Compounds potentially used for diacetyl
formation Lactic acid Oxalacetic
acid Pyruvic acid acetyl lactic
acid Acetaldehyde Citric acid
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Flavor stabalization - Need to protect from
light, heat, oxygen, water - Liquid flavors are
typically dissolved in solvents Partially
hydrogenated oil or brominated vegetable
oil Ethanol, propylene glycol, glycerin
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• Dry flavors are typically encapsulated
• - Spray drying
• - Use of excipients
• Plating - coat flavor onto sugar or salt
• Extrusion - glassy sugar film
• Inclusion complex - beta cyclodextrins
• Secondary coatings - high melting temperature fat

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Flavor interactions pH, tartness of acids
dependent on acid Acidulant, the type of acid
used influences intensity of other
flavors Carbohydrates, can bind flavor
compounds, so less flavor may be needed at low
sugar levels Sweeteners, sweetness can impact
flavor intensity Lipids, flavors partition, fat
helps flavor impact Protein, selective binding
of flavor compounds
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• Flavors complex mixtures of many compounds
• -Amyl, butyl, ethyl esters
• - Amyl acetate sweet fruity/ banana/ pear
• - Amyl caproate sharp fruity/ pineapple
• - Amyl formate sweet/ fruity
• Organic acids containing aldehydes , aromatic
  esters,
• alcohols, ketones
• - Acetic acid vinegary
• - Propionic acid sour milk
• - Butyric acid buttery

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- Green flavors - cis 3-hexenol green leafy -
trans 2-hexenal green apple - Citrus flavors
are mixtures of - Aldehydes - Aromatic
esters - Terpenes - Alcohols - Terpenes -
Limonene sweet citrus/ orange peel - Alpha
pinene warm resinous/ pine-like - Dipentene
fresh citrus/ lemon like
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- Floral aldehydes - Citral floral/ sweet/
lemon (pledge) - Octanol floral/ fatty/
orange-like - Dairy flavors - chemical and
enzymatic -Short chain fatty acids Aliphatic
alcohols - propyl, butyl, octyl -Lactonones -
large chain delta lactones -Aliphatic
aldehydes -acetyldehyde, butyraldehyde
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- Sulfides - dimethyl, butyl, dimethyl
sulfides -Aliphatic esters - butyrates,
laurates, valerates - Di-keytones - diacetyl,
acetylpropionyl - Lactones - undecalactone (C11)
peach/ sweet - octalactone (C8) cooked
coconut/ sweet
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• Brown flavors
• - Caramelized, roasted or burnt character
• Bread-yeast, caramel, chocolate, coffee, maple,
  peanut
• - Sweet brown compounds
• Vanillin sweet/ chocolate-like
• Maltol sweet/ malty/ brown
• Di-hydrocoumarin sweet/ caramel/ nutlike
• - Non-sweet brown compounds
• - Dimethyl pyrazine nutty/roasted
• - 2,3,5 trimethyl pyrazine chocolate/ roasted

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Flavor Compounds Formation by Maillard Reaction
Reducing Sugars and ?-amino acids
N-glycosylamine or N-fructosylamine
1-Amino-1-deoxy-2-ketose (Amadori intermediate)
or 2-Amino-2-deoxy-1-aldose (Heynes intermediate)
Reductones and Dehydroreductones
H2S NH3
Strecker degradation
Amino Acids


Retroaldol Reaction
Glyoxal Pyruvaldehyde Glycerolaldehyde
Strecker Aldehydes CO2 ?-aminoketone
(Methional, NH3, H2S)
Furans Thiophenes Pyrroles
Hydroxyacetone Hydroxyacetylaldehyde Acetoin Acet
ylaldehyde
Heterocyclizaion
Pyrazines Pyridines Oxazoles
Thiazoles Pyrroles
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• - Woody compounds
• - Alpha lonone woody/balsamic/violet/red
  raspberry
• Beta lonone woody/balsamic/black raspberry
• - Spicy compounds
• Cinnamic aldehyde cinnamon
• Eugenol cloves
• Thymol thyme
• Zingerone ginger oil
• Capsicum peppers
• - Sulfur compounds
• - Diallyl disulfide garlic onion
• - Methyl mercaptan natural gas
• - Methyl thio butyrate sour milk

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SOURNESS and sour taste is often thought of as
acid However there is not a simple
relationship between acid concentration (pH) and
sourness Organic acids differ in
sourness CITRIC ACID (0.05 N solution) fresh
taste sensation LACTIC ACID (0.05 N solution)
sour, tart PROPIONIC ACID (0.05 N solution)
sour, cheesy ACETIC ACID (0.05 N solution)
vinegar PHOSPHORIC ACID (0.05 N solution)
intense MALIC ACID (0.05 N solution)
green TARTARIC ACID (0.05 N solution) hard
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BITTERNESS cqn be attributed to several
inorganics and organics KI CsCl
MgSO4 Certain amino acids and peptides (dipeptide
leucine-leucine) Alkaloids derived from pyridine
(N-containing 6-membered ring) and purines
A caffeine (1, 3, 7 trimethylxanthine) B
theobromine (from cacao)
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GYCOSIDES are sugars that have been added to a
natural compound. Grapefruits generally have a
bitter taste to them. This is due to the
flavonoid compound Naringin. Naringin actually
has 2 sugars (bith glucose) as part of its
structure. Compound is still intensely
bitter. Removal of these sugars with
naringinase, will render the compound
tasteless. Naringin is then converted to
Naringinin. The de-bittering of grapefruit
juice can be done, if desired.
Where rutinoside is the sugar
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SALTY depends on the nature of the cation and
anion in the ionic salt crystal structure high
molecular weight salts may be bitter some
salts may even exhibit sweetness
Examples NaCl NaBr NaI KCl LiBr
NaNO3 salty KBr salty bitter Lead
acetate (toxic) sweet
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HOTNESS (pungency) is characteristic of
piperine in black pepper and capsicum in red
pepper and gingerols in ginger
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Sunlight Flavor
Sunlight will induce oxidized flavor and sunlight
flavor and hay-like flavor. Oxidized
flavor Sunlight flavor burnt and / or
cabbage
Riboflavin Effect on Sunlight Flavor

• Riboflavin is a catalyst for production of the
  sunlight flavor.
• Milk protein and riboflavin sunlight
  sunlight flavor
• 2) Riboflavin increase in milk will increase the
  sunlight flavor
• 3) Riboflavin removal prevent the sunlight flavor

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According to the TG Lee Website

• Studies at the Silliker Laboratories in Illinois,
  the University of Michigan and other leading labs
  and universities concluded that both sunlight and
  the fluorescent lighting in stores could decrease
  the freshness and flavor of milk and the potency
  of vital vitamins in it. But this research also
  showed that the majority of natural and
  artificial light could be blocked by containers
  that were yellow instead of white.

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Riboflavin Effect on Sunlight Flavor

• Riboflavin is a catalyst for production of the
  sunlight flavor.
• Milk protein and riboflavin sunlight
  sunlight flavor
• 2) Riboflavin increase in milk will increase the
  sunlight flavor
• 3) Riboflavin removal prevent the sunlight flavor