6 flavor
TRANSCRIPT
Food Flavor
Chapter 11 in your textbook
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Intermolecular Copigmentation
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OCyanidin-3-ß-D-glucoside Cyanidin-3-(6-O-p-coumaroyl-
ß-D-glucoside
Copigment “Stacking”
=
Hyperchromic shiftBathochromic shift
Pigment
Co-Factor
Co-Factor
Anthocyanin Color
The poor stability of anthocyanins creates the need to modify stability or find new sources Increase color and oxidative stability
Result: More red color at higher pH levels Greater application range in foods Enhanced antioxidant capacity; health benefits
AbsAbs
nmnm
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
Sensory Impressions Visual impression
Color, size, shape, luster
Odor Volatile, odor-active compounds
Taste Sweet, sour, bitter, salty
Somato-sensory Pain, burning, cold, warmth, astringent, fizzy
Trigeminal nerve response
Texture, resistance, elasticity Sounds
Modern “Flavor” Chemistry Savory
Roast, Pan Dripping, Seared , Grilled , Braised, Au jus Diary
Milk, cream, dairy, cheese, butter, sweet brown flavors, and dairly masking agents
Fruit Natural, synthetic, WONF, enhancers, mimics, green,
citrus, floral, tropical, exotic, complimentary Beverages
Nutritionally enhanced/fortified, soy milks, tea, coffee, liqueurs, energy, fortified waters, dry drink bases, syrups
Sweet
Molecular Basis of Sweetness
-OH groups Acree and Shallenberger AH/B concept
Acree and Shallenberger… “…(Shallenberger & Acree) published a paper entitled the
"Molecular Theory of Sweet Taste" in Nature [1969]. The model developed in that paper for sweetness was based on
a structure-activity relationship between the simplest sweet tasting compounds and their structural features of the stimulants and has become known as the AH-B theory.
The theory described with considerable success the structural features necessary for sweetness but it was not sufficient to predict sweetness.
That is, not all compounds that satisfied the theory tasted sweet nor was the theory able to predict potency level especially for the very high potency sweetners subsequently synthesized.
However, all sweet compounds seemed to have an identifiable AH-B feature.
AH/B Model
AH – Weak acid, B - electronegative group
The perception of sweetnessis proposed to be due to achemical interaction that takes place on the tongueBetween a tastant moleculetastant moleculeand tongue receptor proteintongue receptor protein
THE AH/B THEORY OF SWEETNESSA sweet tastant molecule (i.e. glucose) is called the AH+/B- “glycophoreglycophore”.
It binds to the receptor B-/AH+ site through mechanisms that include H-bondingH-bonding. Intermolecular, anti-parallel hydrogen-bonding interaction
AH
B
B
AH
Glycophore
γ
γ
Tongue receptor protein molecule
Hydrophobic interaction
For sweetness to be perceived, a molecule needs to have certain requirements. It must be solublesoluble in the chemical environment of the receptor site on the tongue. It must also have a certain molecular shapeshape that will allow it to bond to the receptor protein.
Lastly, the sugar must have the proper electronic distribution. This electronic distribution is often referred to as the AH, B system. The present theory of sweetness is AH-B-X (or gamma). There are three basic components to a sweetener, and the three sites are often represented as a triangle.
AH+ / B-
Gamma (γ) sites are relatively hydrophobichydrophobic functional groups such as benzene rings, multiple CH2 groups, and CH3
Identifying the AH+ and B- regions of two sweet tastantmolecules: glucose and saccharin.
Saccharin Sweet’n Low, The 1st artificial sweetener Accidentally found in 1879 by Remsen and Fahlberg Saccharin use increased during wars due to sugar
rationing By 1917, common table-top sweetener in America Banned in 1977 due to safety issue 1991, withdrew ban, but with warning label 2000, removed warning label Intensely sweet, but slight bitter aftertaste
Aspartame Nutrasweet, Equal Discovered in 1965 by J. Schlatter Composed of aspartic acid and phenylalanine 4 kcal/g, but 200 times sweeter Approved in 1981 for table-top sweetener and
powdered mixes Safety debating 1996, approved for use in all foods and beverage Short shelf life, not stable at high temperature
Sucralose Splenda 1998, approved for table-top sweetener and use
in various foods Approved already in UK, Canada before US Only one “made from sugar”
There was a law suit last year of this claim Splenda lost….not a natural compound….a bit of a
deceptive marketing.
Clean, sweet taste and no undesirable off-flavor
Acesulfame K Sunette, Sweet One Discovered in 1967 by Hoechst 1992, approved for gum and dry foods 1998, approved for liquid use Blending with Aspartame due to synergistic effect Stable at high temperature and long shelf life (3-4
years) Bitter aftertaste
Neotame Brand new approved sweetener (Jan. 2000) 7,000 ~ 13,000 times sweeter than sugar Dipeptide methyl ester derivative; structurally
similar to Aspartame Enhance sweetness and flavor Baked goods, non-alcoholic beverages
(including soft drinks), chewing gum, confections and frostings, frozen desserts, processed fruits and fruit juices, toppings and syrups.
Safe for human consumption
Reb-A (diterpene glucoside)
http://www.reb-a.com/
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 ArtificialNatural - concentrated flavoring constituents derived from plant or animal sources
Artificial - substances used to impart flavor that are not derived from plant or animal sources
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
Flavor Houses
Givaudan
IFF
Bell Flavors
Wild
Sensus Flavors
Virginia Dare
Blue Pacific
Natural flavors can also be enzymatically or chemically produced
- Fermentation reactions- Microbial enzymes
Saccharomyces Sp.Lactobacillus Sp. BacillusSp. Molds
Maillard flavor compounds
Glucose + Glutamic acid = chickenGlucose + Lysine = burnt or fried potatoGlucose + Methionine = cabbageGlucose + Phenylalanine = caramel
Fructose + Glutamic acid = chicken Fructose + Lysine = fried potato Fructose + Methionine = bean soup Fructose + Phenylalanine = wet dog
Artificial Flavors
Typically are esters
Esters have pleasant fruity aromas, derived from acids
a condensation reaction
ACID + ALCOHOL --> ESTER + WATER
Most artificial flavors are simple mixtures of esters
i.e.Isobutyl formate + isobutyl acetate = raspberry
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
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
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
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
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
- 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
- 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
- Sulfides - dimethyl, butyl, dimethyl sulfides-Aliphatic esters
- butyrates, laurates, valerates- Di-keytones
- diacetyl, acetylpropionyl- Lactones
- undecalactone (C11) = peach/ sweet- octalactone (C8) = cooked coconut/ sweet
Gamma-Octalactone
http://www.iff.com/Ingredients.nsf/FragIngredients!OpenForm
Brown flavors
- Caramelized, roasted or burnt character- Bread-yeast, caramel, chocolate, coffee, maple, peanut
- Sweet brown compoundsVanillin = sweet/ chocolate-likeMaltol = sweet/ malty/ brown (flavor enhancer)Di-hydrocoumarin = sweet/ caramel/ nutlike
- Non-sweet brown compounds- Dimethyl pyrazine = nutty/roasted- 2,3,5 trimethyl pyrazine = chocolate/ roasted
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
Furans ThiophenesPyrroles
Retroaldol ReactionH2S
NH3
Strecker degradation
Amino Acids
Hydroxyacetone HydroxyacetylaldehydeAcetoinAcetylaldehyde
Glyoxal Pyruvaldehyde Glycerolaldehyde
Strecker Aldehydes +
CO2 + -aminoketone
(Methional, NH3, H2S)
HeterocyclizaionPyrazinesPyridinesOxazoles
ThiazolesPyrroles
++
- Woody compounds- Alpha lonone = woody/balsamic/violet/red raspberry-Beta lonone = woody/balsamic/black raspberry
- Spicy compoundsCinnamic aldehyde = cinnamon
Eugenol = clovesThymol = thymeZingerone = ginger oilCapsicum = peppers
- Sulfur compounds- Diallyl disulfide = garlic onion- Methyl mercaptan = natural gas- Methyl thio butyrate = sour milk
Sour
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”
Bitter
BITTERNESS cqn be attributed to several inorganics and organics
KI CsCl MgSO4Certain 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)
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 (both 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:
Salty
“SALTY” depends on the nature of the cation and anionin 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
Trigeminal Response
“HOTNESS” (pungency) is characteristic of piperine in black pepper and capsicum in red pepper and gingerols in ginger
“Cool” is a characteristic of mentholPeppermint or mint oils
OH
OMe
OH
eugenol menthol
“Spicy” is a characteristic of eugenolClove, nutmeg, cinnamon, bay leaf
Aromas
Sources of Aromas in FoodNatural flavors
Herbs and spices (some enzymatic rxns) Fruits (biosynthesis during ripening)
Process flavors Browning and Maillard Lipid oxidation Fermentation
Artificial flavors Single compounds with character impact
Isoamyl acetate = bananna
Allium sp.(onions, garlic, shallots, leeks)
S-(1-propenyl)-L-cysteine sulfoxide
Allinase
1-propenyl sulfenic acid
Thiopropanal S-oxide
(Tear maker)
Chemical
rearrangement
Mercaptans (thios)Disulfides
Chemical
Rearrangement w/heat
Lipoxygenase Generated Flavors
COOH
O2
COHCOH
A B
lipoxygenase
hexenal nonadienal
“green” “melon, cucumber”
Vanilla- an extracted flavor
VanillinSeed pods of Planifolia
(a tropical orchid)
Sunlight Flavor
Sunlight will induce oxidized flavor and sunlight flavor and hay-like flavor.
Oxidized flavor Sunlight flavor: burnt and / or cabbage
Riboflavin (B2) Effect on Sunlight FlavorRiboflavin is a catalyst for production of the sunlight flavor.
1) Milk protein and riboflavin sunlight sunlight flavor
2) Riboflavin increase in milk will increase the sunlight flavor
3) Riboflavin removal prevent the sunlight flavor
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.
Riboflavin Effect on Sunlight Flavor
Riboflavin is a catalyst for production of the sunlight flavor.
1) Milk protein and riboflavin sunlight sunlight flavor
2) Riboflavin increase in milk will increase the sunlight flavor
3) Riboflavin removal prevent the sunlight flavor