Food Flavors Flashcards
1
Q
What is a Food Flavour
A
Sensations produced by a food in the mouth and the nose
2
Q
What are the components of Food Flavours
A
- Taste
- Odor or Smell
- Mouthfeel
3
Q
How is taste received and what are the types of taste?
A
♣ we receive on the taste buds called the papillae ϖ Sweet ϖ Sour ϖ Salty ϖ Bitter ϖ Umami
4
Q
Odor or Smell
Name 5
A
ϖ Ethereal ϖ Pungent ϖ Putrid ϖ Floral ϖ Minty ϖ Musky ϖ Camphoraceous
5
Q
Mouthfeel
What are the 3 components
A
ϖ Temperature
ϖ Pain
ϖ Tactical sensations
6
Q
How is Flavour perceived
A
smell signal from the nose + taste signal from the tongue + mouthfeel from teeth, jaws, tongue –> flavour perceived in the brain
7
Q
What makes something Sweet Taste? What are the 3 types of sweetness?
A
o Due to electronegative elements of organic molecules (e.g., O & N):-
♣ alcohols (e.g., glycerol, xylitol) – OH
♣ aldehydes (e.g., cinnamaldehyde) – OH
♣ certain amino acids (e.g., D-Histidine) – N
8
Q
Relative Sweetness of Sugars
A
Reference is sucrose = 1
DECREASING ORDER:
aspartame fructose SUCROSE glycerol mannitol glucose galactose sorbitol maltose lactose
9
Q
Taste of Asp-NH3 (aa) isomers
A
L isomer –> tasteless
D isomer –> sweet
10
Q
Taste of Glu (aa) isomers
A
L isomer –> meaty
D isomer –> tasteless
11
Q
Taste of His (aa) isomers
A
L isomer –> tasteless to bitter
D isomer –> sweet
12
Q
Taste of Ile (aa) isomers
A
L isomer –> bitter
D isomer –> sweet
13
Q
Taste of Try (aa) isomers
A
L isomer –> bitter
D isomer –> very sweet
14
Q
What are traditional sweeteners? Name 5
A
o sugar(sucrose) o invert sugar o conventional corn syrup o high fructose corn syrup o maltodextrin
15
Q
Food Used as Sweeteners
Name 3
A
Honey
Maple Sugar
Molasses
16
Q
What is honey and what is its composition?
A
sweet, syrupy liquid made by honey bees; it is a mixture of fructose (33-40%) & glucose (32-42%) with 15-
20% H2O, & significant content of phenolics.
17
Q
What is maple sugar and what is its composition?
A
mixture of glucose, fructose, and sucrose
- obtained by boiling the sap of the sugar maple tree.
18
Q
What is molasses and what is its composition?
A
the dark syrupy liquid left after recovery of sugar from either sugar cane or sugar beet. Has variable composition.
19
Q
How is molasses made?
A
♣ Sugar cane –> crushing –> juice –> heated sugar crystals or syrup –> sugar crystals and syrup (cane molasses-blackstrap molasses)
♣ As you process more the intensity in the color and the viscosity increases.
♣ Blackstrap molasses in rich in vitamins and minerals such as vitamin B, potassium, iron, calcium, magnesium.
20
Q
Blackstrap molasses is rich in vitamins and minerals such as
A
vitamin B potassium iron calcium magnesium
21
Q
Today’s challenge with sweet taste is ___
A
to provide good tasting sugar-free products (low calorie, non- cariogenic sweeteners)
22
Q
Name Low Calorie, Non-cariogenic sweeteners
A
polyols (xylitol, mannitol, sorbitol, maltitol, lactitol); polydextrose, fruit juices.
23
Q
The 8 Criteria for selecting alternate sweeteners
A
o cariogenicity o sweetness equivalent o solubility o hygroscopicity o heatofsolution o viscosity o laxativeeffect o cost
24
Q
What is Cariogenicity
A
depends on susceptibility to fermentation by oral microorganisms
- Generally, polyols are resistant to fermentation or not fermented appreciably. Thus formation of cavity causing fermentation plaque acids is minimal.
25
Sweetness Equivalent: consumers generally concerned with:
o sweetness
o quality of that sweetness
The alternate sweetener must provide the same sweet taste the consumer associates with sugar, without any objectionable aftertaste.
26
How does Solubility affect Sweeteners
o Solubility can influence mouthfeel, texture & onset of sweetness perception of the product;
o Thus, it is desirable for the alternate sweetener to have similar solubility profile as traditional sugar;
o Alternate sweeteners with low solubility result in products with a chalky mouthfeel
27
Viscosity in Sweeteners
| Give examples
o The viscosity of the alternate sweetener can influence products’ characteristics
e.g., xylitol is less viscous than sugar (or maltitol) and can yield a poor bodying effect;
polydextrose has higher viscosity than sucrose.
Combinations of xylitol with polydextrose help to produce desired products.
28
What is Hygroscopicity in Sweeteners?
- Give examples
- How is the shelf-life of hygroscopic sweeteners and how does that affect the packaging?
is the phenomenon of attracting and holding water molecules from the surrounding environment, which is usually at normal or room temperature.
o Hygroscopicity can affect shelf-stability of a product;
o Mannitol & isomalt are non-hygroscopic, while the remaining polyols are fairly hygroscopic;
o Shelf-life of products from high hygroscopic materials is relatively short; the products may even require individual wrapping.
29
Heat of Solution or Cooling Effects in Sweeteners
- Which sweeteners have the most cooling effect?
- What are the advantages of cooling effects?
ϖ when crystalline polyols dissolve, the relatively lower heat of solution (versus sugar) produces a pleasant cooling effect in the mouth, and gives them a “taste edge” over sugar in many applications
- e.g., mint flavors
ϖ xylitol has the most cooling effect; mannitol and sorbitol also produce significant cooling effects
ϖ isomalt produces marginal cooling effect
ϖ the cooling effect due to sucrose is very limited and similar to that of maltitol
ϖ Some applications that take advantage of the cooling effects are:- chewing gum, tablets, mints, lozenges, coatings, fondants, hard candies & certain chocolates.
30
Laxative effects of sweeteners
Which sweeteners have laxative effect?
What is the concern?
o Polyols and polydextrose have laxative effect– because they are incompletely digested and slowly absorbed;
o Food which provide>50g sorbitol/day or >20g mannitol /day are required to pose a label warning statement concerning the potential laxative effect. It is the same with foods providing >15 g polydextrose/day.
31
Cost considerations in using Sweeteners
| - Which sweeteners are more expensive than the others?
o Cost is a major factor in selecting alternate sweetners;
o On a dry solids basis, maltitol is about 5x more expensive than corn syrup, sorbitol is about 2 to 3 times as expensive as sugar;
o Mannitol, xylitol, isomalt, and maltitol are even much more expensive.
32
Relative sweetness of selected alternate sweeteners:
```
xylitol
polydextrose
mannitol
maltitol
isomalt
sorbitol
```
xylitol > maltitol > mannitol > sorbitol > isomalt > polydextrose
33
Xylitol vs Sucrose
Xylitol is isosweet with sucrose (less viscous than sucrose in solution)
34
Sweetness synergism occurs between sweeteners for formulation benefits examples:
e. g.,
3: 2 ratio of xylitol to sorbitol in chewing gum;
4: 1 ratio of maltitol & xylitol in chocolate produce sugar-free products.
35
True/False
Sorbitol is more viscous than sucrose in solution
True
sorbitol or polydextrose are more viscous than sucrose in solution.
36
What is synergistic effect of sweeteners
♣ by using blends of the polyols, we can have combination that are similar to sucrose in sweetness and viscosity – SYNERGISTIC EFFECT
♣ Synergistic effect produced by blending,
37
Xylitol
- compare its sweetness to other sugars
- is isosweet to ____
- name one pro and one con
o sweetest of the polyols
o is isosweet to sugar
o without discernible after taste;
* Xylitol is metabolized independently of insulin - thus, is a useful ingredient in diabetic foods;
* It is resistant to fermentation by oral bacteria (e.g., Streptococcus mutans). Thus, does not cause pH decline (as with sucrose) to demineralize tooth enamel and cause decay.
38
Some Technical Characteristics of Xylitol
```
o high thermal stability;
o high microbiological stability;
o inhibits many food - spoilage organisms;
o does not react with amino acids;
o moderate hygroscopicity.
```
39
Some Applications of Xylitol
o in chewing gum and other confectionery;
o in pharmaceuticals (e.g., syrups, chewable tablets);
o in oral hygiene products (toothpaste, mouthwash)
o in diabetic foods.
40
High Intensity Natural Sweeteners
| - Name 4 main and others
```
Amino acids
Miraculin
Thaumatin
Stevia
Others are: monellin, brazellin, neoculin (all from plants found in tropical rainforests) & mabinlin (China).
```
41
Amino acids as high intensity natural sweeteners
- Give examples (be specific)
- Which isomer is sweeter? D or L? Prove
e.g., D-His; D-Leu; D-Try; D-Tyr & Gly). In general, the D-amino acids tend to be sweet & the L-
isomers are bitter; some exceptions are D-Ala which has an insipid taste and L-Ala which is sweet
• D-Try~35x sweeter than sucrose; its synthetic derivative 6-chloro-D-Try is ~1000x sweeter than sucrose.
42
Miraculin
- what is it?
- what is its major property?
high intensity natural sweetener
a glycoprotein from berries found in West Africa. The fruit of this plant is commonly referred to as the miracle fruit. Has the unusual property of tasting intensely sweet only in the presence of acids.
43
Thaumatin
- what is it?
- where is it found?
- What is its relative sweetness?
high intensity natural sweetener
a mixture of sweet-tasting proteins found in the African fruit known as katemfe. It is about 1,500- 2,500x sweeter than sucrose.
44
Stevia
- what is it?
- where is it found?
- what is the active compound?
high intensity natural sweetener
a shrub found in the tropical and sub-tropical zones of the Americas.
Active compound is steviol glycoside
45
Miracle Fruit
| - what is its major characteristic?
miraculin
Has the unusual property of tasting intensely sweet only in the presence of acids.
46
High Intensity Synthetic Sweeteners
| - Name 6
```
Saccharin
Cyclamates
Aspartame
Acesulfame K
Sucralose
Alitame
```
47
Saccharin
- What is it?
- What is its relative sweetness?
- what is its nickname?
(Na or Ca salts - ~200-400x sweeter than sucrose); a.k.a. Sweet ‘N Low
48
True/False
L- amino acids are generally sweeter than the D-forms (might have insipid or bitter tastes)
false
D- amino acids are generally sweeter than the L-forms (might have insipid or bitter tastes)
49
In synthetic sweeteners, what are the tastes perceived from L and D isomers
ϖ D-insipid
| ϖ L-sweeter
50
Cyclamates
- what is it?
- what is its relative sweetness?
- what is its disadvantage?
- what is its nickname?
Na or Ca salts - ~30-40x sweeter than sucrose).
* Converted to cyclohexylamine - a carcinogen, by intestinal bacteria in certain individuals);
a. k.a. Sugar Twin
51
Aspartame
- what is its chemical composition?
- what is its relative sweetness?
- how is it used?
- what is its nickname?
the methyl ester of the dipeptide, L-aspartyl- L-phenylalanine;
about 200x sweeter than sugar;
approved in early 1980’s for use as table-top sweetener, in dry beverage mixes, and in foods that are not heat processed;
a.k.a. Equal / NutraSweet
52
Acesulfame K
- what is it chemical compound?
- what is its relative sweetness?
- what is it key characteristic?
- what is its nickname?
tisK-saltofmethyl-oxathiazine- dioxide;
about 200x sweeter than sugar;
more stable than other synthetic sweeteners;
and sweet taste is clean and does not linger;
a.k.a. Ace-K, Sunett, Sweet One.
53
Sucralose
- what is it chemical compound?
- what is its relative sweetness?
- what is it key characteristic?
- what is its nickname?
trichloro derivative of glucose-fructose;
~600x sweeter than sucrose.
More stable than sugar, and appears to be very suitable for several food uses;
a.k.a. Splenda
54
Alitame
- what is it chemical compound?
- what is its relative sweetness?
- what is it key characteristic?
- what is its nickname?
a derivative of the dipeptide L-α- aspartyl-alaninamide.
It is about 2,000-3,000x sweeter than sucrose;
a.k.a. Aclame
Alitame is stable to heat, which is a definite advantage over aspartame in some food applications.
55
Alitame vs Aspartame
Alitame is stable to heat, which is a definite advantage over aspartame in some food applications.
56
Sweet ‘N Low
Saccharin
57
Sugar Twin
Cyclamates
58
Equal / NutraSweet
Aspartame
59
Ace-K, Sunett, Sweet One.
Acesulfame K
60
Splenda
Sucralose
61
Aclame
Alitame
62
```
Sour Taste (or tartness)
- how is it perceived?
```
o Due to H+ ions from acids (e.g., lactate, pyruvate, acetate, malate, etc.)
o [H+] determines degree of sourness, not the total acidity
o Other contributory factors - nature of acidic group, buffering capacity, presence of other
compounds.
63
Organic acids used in food are ______
| majority of the acids used in food industry
name 8 of them
```
acetic acid,
citric acid,
fumaric acid,
lactic acid,
tartaric acid,
malic acid,
benzoic acid,
sorbic acid
```
64
Inorganic acids used in foods are _____
H3PO4 (phosphoric acid)
HCl (hydrochloric acid)
65
Acidulants are used for various reasons
| name 6
o Optimum acidity in desserts, sugar confectionery, fruit-flavored beverages enhances flavor of product;
o curtails microbial activity / metabolism and prevents spoilage;
o slows down or even stops the action of several enzymes - thus, preventing food spoilage by autolysis;
o Acids enhance the action of natural anti-oxidants;
o Important to have the right acidic pH during wine
processing to obtain stable products;
o In pectin-based jams and jellies, gel strength depends on the use of the correct acidity
66
High concentrations of [H+] --->
| Low concentrations of [H+] --->
more sour
| less sour
67
Acetic Acid
- what is its formula?
- how is it obtained?
- what is its generic name?
- what is it used for?
CH3COOH
o It is a clear, colourless liquid, prepared commercially by oxidation of ***acetaldehyde or ***butane;
o Used in industry as vinegar - to preserve pickles, sauces, relishes, and also imparts sharp piquancy & aromatic flavour to foods;
o Vinegar produced by yeast fermentation of fruit juices, sucrose, glucose, malt, etc.
68
Acidic Acid
- what is its chemical formula?
- what is it and how is it produced?
- what is its solubility like?
- what is it classified as and for what property?
(CH2)4(COOH)2
o It is an odorless, white crystalline powder produced on a commercial scale by oxidation of cyclohexanol;
o Has limited solubility in H2O, but is very soluble in alcohol and acetone;
o Classified as GRAS; a general purpose acidulant - as buffering and neutralizing agent.
69
Citric Acid
- what is its formula?
- compare it with all other acids
- how is it produced
- what is its solubility like
- what is its general purpose?
C6H807
o It is the most widely distributed of the natural acids-in fruits & vegetables;
o Produced commercially from pineapple waste;
o Highly soluble in H2O & alcohol;
o Classified as GRAS; has been used as general purpose acidulant for decades.
70
Fumaric Acid
- what is its formula?
- how is it produced
- what is its solubility like
- what is its general purpose? Where is it used?
HO2CCH=CHCO2H
o It is an odorless, white granular or crystalline powder produced during fermentation of glucose or molasses by Rhizopus species;
o Sparingly soluble in H2O, soluble in ethanol (EtOH);
o Widely used in dry powdered food products where solubility is not a significant quality factor - but where its preservative / antioxidant properties are of more value (e.g., in rice, mushroom, gelatin).
71
Lactic Acid
- what is its formula?
- what is its physical characteristics
- how is it produced?
- what is its general purpose? Where is it used?
C3H6O3
o It is a viscous, colorless to pale yellow, non-volatile liquid with distinct odor (PUNGENT);
o Produced commercially by controlled fermentation of sucrose, potato starch, molasses, etc.;
o Commonly used acidulant in fermented and dairy products.
72
Malic Acid
- what is its formula?
- how is it produced
- what is its solubility like
- What is the commercial product composed of?
- what is its general purpose? Where is it used?
HO2CCH2CHOHCO2H
o It is an odorless, white crystalline powder; soluble in H2O and EtOH;
o The commercial product is a racemic mixture of the D- & L- isomers;
o Used in non-alcoholic beverages, canned tomatoes, fruit products, and fruit pie fillings.
73
Propionic Acid
- what is its formula?
- what are its physical characteristics like?
- what is its solubility like
- what is its general purpose? Where is it used?
CH3CH2COOH
o It is an oily liquid with as light pungent/rancid odour. On dilution, resembles butyric acid;
o Completely miscible with H2O & EtOH;
o Used more in baking to suppress mold growth.
74
Sorbic Acid
- what is its formula?
- what are its physical characteristics like?
- what is its solubility like
- what is its general purpose? Where is it used?
C6H8O2
o It is an almost odourless, white crystalline substance with a slight acidic taste;
o Limited solubility in H2O & EtOH. K, Na, and Ca salts soluble in H2O, and release free acid in low pH media;
o Salt forms used more for their anti-fungal and preservative properties.
75
Succinic Acid
- what is its formula?
- what are its physical characteristics like?
- what is its solubility like
- what is its general purpose? Where is it used?
HOOC-(CH2)2-COOH
o It is an odourless, white crystalline solid with a sharp acidic as well as a slight bitter taste;
o Soluble in both H2O and EtOH;
o A general purpose GRAS status acidulant.
76
Succinic Anhydride
- what is its formula?
- what are its physical characteristics like?
- what is its solubility like
- what is specific about it in food industry?
- what is its general purpose? Where is it used?
C4H4O3
o It is a white crystalline powder - stable when dry, but converted to succinic acid when dissolved in H2O;
o It is the only anhydride permitted for commercial use in foods;
o Mostly used as a leavening agent in baked goods.
77
Tartaric Acid
- what is its formula?
- what are its physical characteristics like?
- what is its solubility like?
- where does it occur?
- what is its general purpose? Where is it used?
C4H6O6
o It is a colourless, translucent crystalline powder;
o It is odourless, but has strong acidic taste and very soluble
in H2O & EtOH;
o Occurs in many fruits, especially grapes, and is obtained as the K or Ca salt during wine fermentation;
o GRAS status general purpose acidulant.
78
Phosphoric Acid - Inorganic Acid
- what is its formula?
- what are its physical characteristics like?
- what is its taste like?
- what is its general purpose? Where is it used?
(H3PO4)
o it is a colourless, crystalline solid; but commonly used in the form of a clear, syrupy liquid with conc. ranging from 75-85%;
o Has flat taste which enables it to blend very well with non-fruit flavors;
o Used in formulating cola drinks, and in cheese making / brewing for pH control.
79
Salty Taste
- how is it perceived
- what does it depend on
o The salty taste is due to salt ions (e.g.,Na+,K+,Cl-,etc);
o Salty taste dependent on size of ions (the smaller sized
ions are salty; the larger sized ions tend to be bitter).
80
Examples of Salts and their taste
LiCl ; LiBr ; NaNO ;, NaCl ; KCl --> SALTY
CsCl; KI ; MgSO4 --> BITTER
PbAc ; BeAc --> SWEET
81
LiCl ; LiBr ; NaNO ;, NaCl ; KCl
SALTY
82
CsCl; KI ; MgSO4
BITTER
83
PbAc ; BeAc
SWEET
84
NaCl
- what are the major 3 functions in food
- how does it affect digestion
- how can we tolerate and what happens when we go over the limit
- what are the health affects in excessive use
- how are enzymes affected by presence of salt
o Sodium chloride has been used for centuries to impart salty taste (flavor) to foods, and/or to preserve foodstuffs; - decrease water activity
o Other functions of NaCl: as a digestive stimulant, and as a flavor enhancer. Salt enhances the production of stomach acid HCl – increases digestion --> Lipases need to be in the hydrophobic environment
o Most individuals can tolerate up to 2% salt (as NaCl) in their diets. Beyond this concentration, NaCl may render the resulting product indigestible or nauseating – electrolytes
o The use of salt (as NaCl) has become a major health issue with the general public - because of perceived link of Na ions with hypertension or high blood pressure in certain individuals.
o Most enzymes lose activity in presence of a lot of salt. The conformation of the enzyme gets distorted. Not all enzymes are like this.
85
Some Approaches Used to Reduce NaCl levels in Foods
| Give 4 options
o Addition of spices:- (e.g., dry mustard, marjoram, sage, thyme, bay leaves to beef; onion, garlic, sage to pork; paprika, mushroom, parsley to chicken; paprika, curry, bay leaves, lemon juice to fish);
o Salt Substitutes:
(a) Mineral-based substitutes - salts of ions other than Na+ (e.g., K+ & NH4+) to simulate NaCl in taste;
(b) Vegetized Salt Substitutes:- are common salt with powdered dehydrated vegetables (e.g., onion, garlic, celery) as base;
o Na compounds may also be replaced with compounds of other cations in food products (e.g., KHCO3 may be substituted for NaHCO3 in baking)
o Commercial salt substitutes include NH4Cl (from 4-50%), KCl (9- 95%), citric acid & citrates, starch (1-25%), glutamic acid & glutamates, etc.
86
Bitter Taste
o Bitter taste in foods due to various organic & inorganic compounds;
o Bitter taste is unpleasant; however, in combination with other taste sensations, it contributes significantly to consumer acceptance of various products.
87
Bitter compounds in foods are mostly of ______ origin
plant
88
Three classes of organic compounds responsible for bitterness in foods are_______
the alkaloids,
glycosides,
certain amino acids / peptides
89
Alkaloids
- what are they?
- give 3 examples
Nitrogenous compounds widely distributed in plants as salts with acetic acid, or a carboxylic acid
o Examples are quinine, caffeine and theobromine
90
Examples of Alkaloids
quinine
caffeine
theobromine
91
Quinine
- category
- physical characteristics
- solubility
- fun fact
- usage
Alkaloid
o a white amorphous powder with limited solubility in H2O, although the sulfate and hydrochloride salts are H2O-soluble;
o One of the most bitter substances known;
o Used in beverages.
92
Caffeine
- category
- physical characteristics
- solubility
- fun fact
- usage
Alkaloid
o a crystalline purine derivative found in coffee beans (1.5%), tea leaves (5%), & cola nuts (2.5%), etc.;
o Solubility in H2O is 1:50 (~25oC) or 1:2 (~65oC);
o A powerful stimulant with GRAS status.
93
Theobromine
- category
- physical characteristics
- usage
Alkaloid
o structurally related with caffeine, and often found together with caffeine in various plants,
o e.g., cocoa beans (~2%); cola nuts (~0.02%).
94
Glycosides
- what are they
- give 4 examples
are aglycones esterifed with various sugars,
e.g., are naringin, hesperidin, coniferin, and sinigrin.
95
Examples of Glycosides
naringin
hesperidin
coniferin
sinigrin
96
Naringin
- where is it found
- fun fact
- what is the outcome of its hydrolysis
found predominantly in grapefruit and bitter orange;
it is one of the most bitter substances known
o Hydrolysis yields D-rhamnoglucose, and the aglycone – naringenin.
97
Hesperidin
- where is it found
- what is the outcome of its hydrolysis
Found in sweet orange and several other citrus fruits;
yields rutinose and the aglycone hesperetin on hydrolysis.
98
What does narigin yield to when hydrolyzed?
D-rhamnoglucose and aglycone-naringenin
99
What does hesperidin yield to when hydrolyzed?
rutinose and aglycone-hesperetin
100
Coniferin
- where is it found
- what is the outcome of its hydrolysis
- what is the outcome if its oxidation
in conifer wood, it produces coniferyl alcohol on hydrolysis - which may subsequently be oxidized to vanillin;
101
What does coniferin yield to when hydrolyzed?
it produces coniferyl alcohol on hydrolysis
102
What does oxidation of coniferyl alcohol yield?
vanillin
103
Sinigrin
- what is it
- what is the outcome of its hydrolysis
in black mustard seed, it yields glucose and allyl isothiocyanate on hydrolysis
104
What does sinigrin yield to when hydrolyzed?
glucose and allyl isothiocyanate
105
Taste inhibition and/or modification concept
- what is it
- give example
- what are the factors that affect it
o Some compounds can alter the taste elicited by other compounds (e.g., gymnemic acid makes taste buds insensitive to sweet & bitter);
o “Miracle fruit” makes bitter and sour compounds taste sweet;
o Effects of colds or flu & inherited defects.
106
Taste Sensitivity
- criteria
- threshold
- example for threshold
o Criteria - solubility and concentration; - saliva
o Concept of “threshold values” – minimum amount that needs to be dissolved in order to sense the taste.
o Taste has a higher threshold value
o Ex. Pineapple smell in the air can be easily sensed by the nose but more volatile acids are needed to taste it, we need to cut the fruit and eat it in order to taste it
107
Which one has a lower threshold value? Taste or smell
Smell
o Ex. Pineapple smell in the air can be easily sensed by the nose but more volatile acids are needed to taste it, we need to cut the fruit and eat it in order to taste it
108
Taste Interaction
- define
- examples
o Effects of various taste-producing compounds on others;
o Sub-threshold levels of salt reduces sourness in foods;
o Sub-threshold levels of acids enhances saltiness in foods;
o Sub-threshold levels of sugars reduces saltiness in foods.
109
Salt + Sour
salt reduces the sourness
110
Acid + Salt
acid enhances saltiness
111
Sugar + Salt
sugar reduces saltiness
112
Flavour Enhancers
- define
- give 3 examples
o Compounds that improve or intensify flavour quality in foods;
```
o Monosodium Glutamate (MSG);
o Nucleotides (e.g., IMP & GMP);
o Maltol (3-hydroxy-2-methyl-4-pyrone).
```
113
Why is it important to have acids in foods? Acids used for preservation
1. By lowering the pH. microorganisms don’t grow and enzymes don’t function well
2. Enhance the activity of antioxidants, the molecule (acid) is stable, if you have acids that have the –COOH group,
114
Give examples for adjectives that describe texture
firm/soft
grainy/smooth
brittle/musky
115
Give examples for adjectives that consistency
♣ Thin/thick
♣ Smooth/curdled
♣ Lumpy
116
What is astringency
Dry sensation in the mouth
117
What is sensory evaluation?
Analysis of food for its sensory properties
118
What are the 2 sensory evaluation methods?
o Preference Testing
| o Difference Testing
119
Preference testing is more useful in ____
new food product development, where large segment of population is used to verify product acceptability.
120
Three methods commonly used in preference testing:
o the paired comparison test;
o the hedonic scale;
o the ranking test.
121
What is Simple Paired Comparison Test in preference testing?
A pair of samples is provided to panel who are asked to select the one they prefer in terms of a particular attribute
122
What is the Hedonic Scale
```
♣ 9 point systems used to verify degree of likeness or dislikeness of a product
i. like extremely
ii. like very much
iii. like moderately
iv. like slightly
v. neither like or dislike
vi. dislike slightly
vii. dislike moderately
viii. dislike very much
dislike extremely
```
123
What is ranking testing?
♣ panel is provided with more than 2 samples and asked to rank them in order of preference
♣ e.g. 1st, 2nd, 3rd, 4th, …
124
What is difference testing? (DT)
Useful for assessing differences in sensory quality of foods
125
What are the 6 methods of difference testing?
```
o Simple paired comparison test;
o Scheffé paired comparison test;
o Multiple comparison test;
o Triangle test;
o The duo-trio test;
o Ranking test.
```
126
Scheffe Paired Comparison Test
Similar to the simple paired comparison test, except that panel is asked to indicate or quantify degree of difference.
127
Multiple Comparison Test
♣ 3 or more samples are compared against one another A, B, C, D
A-B, A-C, A-D, B-C, B-D, C-D
128
Triangle Test
♣ In this test the panel is presented with 3 samples and told that two of them are identical, and required to pick the odd one
♣ A, B, C
♣ Probability of guessing the right answer is lower
129
The Duo-Trio Test
♣ Panel is presented with 3 samples but given but one of them as reference
♣ e.g. if C is given as reference panel is asked to pick which one among A, B is similar to C
less challenging
130
Seven primary odors, namely
```
o Ethereal (thin rod-shaped molecules)
o Camphoraceous (hemispherical-shaped
molecules; ~7A in diameter)
o Musky(flat disk shaped; ~10A in diameter)
o Floral (shaped as keyholes)
o Minty (wedge-shaped molecules)
o Pungent (negatively charged molecules)
o Putrid (positively charged molecules)
```
131
Ethereal smell molecule shape
thin rod-shaped molecules
132
Camphoraceous smell molecule shape
hemispherical-shaped
| molecules; ~7A in diameter
133
Musky smell molecule shape
flat disk shaped; ~10A in diameter
134
Floral smell molecule shape
shaped as keyholes
135
Minty smell molecule shape
wedge-shaped molecules
136
Pungent smell molecule shape
negatively charged molecules
137
Putrid smell molecule shape
positively charged molecules
