Food flavors - Salt, bitter, umami + extra Flashcards
- salty taste due to what? (3 ex)
- salty taste depends on what? –> how?
- salt ions! (Na+, K+, Cl-)
- depends on size of ions –> smaller sized ions are salty vs larger sized ions tend to be bitter
are these salt: sweet, salty, sour, bitter, umami?
- Pb acetate and Be acetate
- MgSO4
- monosodium glutamate
- KCl and LiCl
- K-bitartrate
- KI and CsCl
- LiBr
- Pb acetate and Be acetate: sweet
- MgSO4: bitter
- monosodium glutamate: umami
- KCl and LiCl: salty
- K-bitartrate: sour
- KI and CsCl: bitter
- LiBr: salty
salts have been used for centuries for 3 functions
- impart salty taste –> impart flavor to foods
- preserve foodstuff –> curtail microbial growth and proliferation
- salts can stimulate digestion and enhance appetite –> digestive stimulant!
what is the max threshold for salt concentration?
2-2.5% salt (as NaCl) –> above this concentration, NaCl may render the resulting product indigestible or nauseating
use of salt (NaCl) has become a major health issue with general public
- link with what? how?
- with hypertension/high blood pressure
- Na+ = intracellular ion in body required to achieve chemical/electrical balance –> increase [Na+] in cell –> osmosis: cell will absorb water –> water exerts pressure on cell wall = increase blood pressure
4 approaches to reduce NaCl levels
- without doing what?
- without compromising salty taste
1. addition of spices: dry mustard, marjoram, onion, garlic, sage, paprika, mushroom, curry, bay leaves, lemon juice
2. mineral-based salt substitutes (salts of K+ and NH4+ ions)
3. vegetized salt substitutes: salt(NaCl) + powdered dehydrated vegetables (onion, garlic, celery) as base
4. Na compounds may also be replaced with compounds of other cations in food products (ie: replace baking powder (NaHCO3) in baking by KHCO3)
- bitter taste in foods is due to various _______ and ________ compounds
- bitter taste is ________ –> but in ___________ with other taste sensations, it contributes significantly to consumer ________ of various products + we have come to accept taste with some products
- examples of foods that tend to be bitter
- organic and inorganic compounds
- unpleasant –> but in combination… consumer acceptance
- kale, bitter melon, broccoli, eggplant, coffee, tea, some cheeses
bitter compounds are mostly of _______ origins
- 3 classes of organic compounds responsible for bitterness in foods are ?
- plant
- alkaloids, glycosides, certain amino acids/peptides
ALKALOIDS:
- _________ compounds widely distributed in plants as _______ with 2 types of acids
- 3 examples
- nitrogenous –> as salts with acetic acid or carboxylic acid
- quinine, caffeine, theobromine
QUININE:
- what color?
- ______ powder
- soluble in water?
- very bitter?
- used in what?
- used to treat what?
- white
- amorphous/shapeless powder
- limited solubility in water although sulfate and hydrochloride salts are H2O soluble
- one of the most bitter substances known
- in beverages
- used to treat malaria
CAFFEINE:
- __________ _______ derivative found in (3)
- solubility in water is 1:50 OR 1:2 depending on what? –> solubility increases with what?
- powerful ________ with GRAS status
THEOBROMINE
- related to ____A___ and found together with it in (2)
- difference to ___A______
- crystalline purine derivative found in coffee beans (1.5%), tea leaves (5%) and cola nuts (2.5%)
- depends on temperature! increase temp = increase solubility
- powerful stimulant!
THEOBROMINE: - related to coffee and often found together in various plants (cocoa beans and cola nuts)
- lacks 1 methyl group attached to N in purine ring
GLYCOSIDES:
- are _______ esterified with various ________
- 4 examples
- what has to be there to elicit bitter taste?
- aglycones esterified with various sugars
- naringin, hesperidin, coniferin, sinigrin
- sugar has to be there! if only aglycone –> bland taste
- these are types of what?
NARINGIN: - found in (2)
- bitter?
- hydrolysis yields (2)
HESPERIDIN:
- found in (2)
- hydrolysis yields (2) –> what confers bitter taste?
- types of glycosides! –> bitter taste!
NARINGIN: - found predominantly in grapefruit and bitter orange
- one of most bitter substances known
- D-rhamnoglycose and aglycone naringenin (if only naringenin = bland)
HESPERIDIN: - sweet orange and several other citrus fruit
- rutinose + aglycone hesperetin –> needs rutinose to taste bitter
- these are types of what?
CONIFERIN: - in what (1)?
- produces 2 on hydrolysis –> which may be subsequently be oxidized to ________
SINIGRIN: - found in what?
- yields what? on hydrolysis
- types of glycosides! –> bitter taste
CONIFERIN: - in conifer wood
- produces glucose and coniferyl alcohol –> vanilin
SINIGRIN: - black mustard seed
- yields glucose + allyl isothiocyanate
PEPTIDES/AMINO ACIDS –> can yield ______ taste
- hydrophilic or hydrophobic aa will impart this taste?
- examples of aa (3)
HE SHOULD SEND A SLIDE WITH MORE INFO!
- bitter!
- hydrophobic!
- proline, isoleucine, valine
UMAMI TASTE:
- describe using 7 words
- perceived in mouth from eating foods such as (3)
- taste due to interactions btw what and what?
- meaty, savory, brothy, pleasant, delicious, appetizing and salivating
- muscle foods, mushrooms, fermented products
- due to interactions of umami eliciting substances like glutamates (MSG), nucleotides (IMP, GMP) and their mixtures with specialized receptors in taste buds
- what is MSG formed from?
- does MSG impart umami taste? how can it do it?
- L-glutamic acid + sodium –> will hydrolyze in food products into glutamic acid
- NO! salt by itself will not give off particular taste! –> salt added to food product will help enhance flavors + bring out umami flavors
how can nucleotides impart umami taste?
specialized receptors in taste buds bind nucleotides –> sends signal to release saliva –> saliva contains digestive enzymes that will hydrolyze proteins –> aa impart umami flavor
how can fermentation impart umami taste?
fermentation (+ enzymatic and chemical modification) can break down compounds/proteins = umami taste
- ie broth, kimchi, soy sauce
- umami eliciting ingredients co-exist in ______ _____ materials –> they act ____________ to enhance sensation in all kinds of foods including (2)
- due to its increasing demand for food applications, it is produced on a ___________ scale using (3)
- agricultural raw materials –> act synergistically –> including ready-to-eat foods + convenient packaged foods
- commercial scale using fermentation, enzymatic hydrolysis and acid hydrolysis methods
Taste sensitivity
- 2 criteria?
- need to reach what
- solubility and concentration
- need to reach threshold values –> minimal amount for taste buds to taste
some compounds can alter taste elicited by other compounds
- ie: gymnenic acid –> does what?
- miracle fruit does what?
- gymnenic acid makes taste buds insensitive to sweet and bitter
- miracle fruit makes bitter and sour compounds taste sweet
what are the effects of colds or flu and inherited defects on taste inhibition/modification?
- ageusia vs hypogeusia vs dysgeusia
GENETICS DEFECTS:
- genetic defects can cause variations in genes that interact with receptors in tongue to elicit particular taste sensations
- Ageusia: variation in phenylthiocarbonate (PTC) gene –> makes taste buds insensitive to taste sensations
- hypogeusia: variations in genes elicit diminished capacity to perceive sensations
- Dysgeusia: gene variations may induce certain permanent unpleasant sensations in mouth such as metallic, rancid, salty taste
GEQ!! why do foods not taste the same when we have a cold?
NEED TO GOOGLE ANSWER!
How can there be food interactions?
- subthreshold levels of ______ reduce sourness in foods
- subthreshold levels of ______ ENHANCES saltiness in foods
- subthreshold levels of ______ reduce saltiness in foods
foods = complex systems –> many many compounds coexist with each other –> can produce synergistic effects
- SALT reduces SOURNESS
- ACIDS enhance SALTINESS
- SUGARS reduces SALTINESS
3 compounds can improve/intensify flavor quality in foods (increase sensation of taste of certain food products
- monosodium glutamate: brings out umami flavors of veg and other foods
- nucleotides (IMP and GMP): increase sweetness of muscle foods
- maltol (3-hydroxyl-2-methyl-4-pyrone): nutty flavor –> enhances flavors of baked goods
- mouthfeel of foods sensed by (2)
- 3 different sensations + give examples
- sensed by teeth and jaw
1. pain: burning sensations in tongue –> ginger, hot chili peppers, wasabi
2. temperature: hot or cold
3. tactile sensations (sensed by both touching and sensations in mouth) –> texture, astringency and consistency
- pain in mouth desirable?
- pain caused by which compounds (2)
- slight pain can be pleasant VS too much = undesirable
- capsaicin and gingerbain –> bind to pain sensing receptors in mouth
why does melted ice cream taste sweeter than frozen?
- why do hot foods taste more intensely?
- frozen foods numb your taste receptors –> sensations are less well perceived
- hot foods dissolve faster –> more kinetic energy = interact more effectively with receptors –> sensations feel more intensely
GEQ: why can milk relieve pain sensations from capsaicin and not water?
- because capsaicin is fat soluble and will dissolve in fats contained in milk –> lowers concentration of capsaicin
- MOSTLY because casein proteins will act as a detergent and bind to capsaicin to make it more soluble –> caseins can also degrade capsaicin
GEQ: what are some differences in pain sensations due to hot chili peppers vs hot coffee?
GOOGLE ANSWER!
examples of how to describe:
- texture
- consistency
- astringency
- texture: hard, soft, brittle, crunchy, grainy
- consistency: smooth, lumpy, curdled, thick, thin
- astringency: dry sensations in cheeks/mouth due to precipitation of proteins in saliva in mouth
sensory evaluation used to verify what?
- 2 methods? + definition
- who can participate?
- verify consumer’s preferences/acceptance of food products
1. PREFERENCE testing: useful for new product development –> checks if consumers like it or not compared to existing products on market - anyone can participate!
2. DIFFERENCE testing: useful to assessing differences in sensory quality of foods - requires panel trained to be able to discern particular taste sensations and to discriminate levels of intensities to achieve useful results
3 methods commonly used for preference testing? + describe
- SIMPLE PAIRED COMPARISON TEST:
- A vs B compared for a particular attribute for which they like (ie A is saltier than B) - HEDONIC SCALE:
- describe taste material with various epithets
- most commonly used is 9 point scale from dislike extremely (1) to neither like or dislike (5) to like extremely (9) OR reversed - RANKING TEST:
- 2 or more test samples ranked against each other in terms of particular attribute (ie A is 1st and B is 2nd)
6 common methods for difference testing + explain
- SIMPLE PAIRED COMPARISON TESTING:
- A vs B - SCHEFFÉ PAIRED COMPARISON TEST: like #1 but quantify how much preference is (ie I prefer A 50% more than B)
- MULTIPLE COMPARISON TEST: 3 or more samples –> compare A & B, B & C, A & C
- TRIANGLE TEST: 3 samples: 2 identical + 1 different –> choose odd one out
- DUO-TRIO TEST: 3 samples: 1 = reference, pick the odd one out of the 2 others
- RANKING TEST: rank in order of intensity 2 or more samples for particular attribute (ie color, sweetness)
GEQ: which of triangle test or duo-trio test would achieve more reliable results? why?
- triangle test is harder bc duo-trio test gives you a reference (?)
- GOOGLE!
odor/smell = component of ________
- (#) of distinct odors due to what? (2)
- give examples
- component of flavor!
- 7 distinct odors –> due to shape and sizes of particular molecules
1. ehereal
2. camphoraceous
3. musky
4. floral
5. minty
6. pungent
7. putrid
*check slide for more details but prof said to not focus
