Lecture 1 : Intro Flashcards
What are functional flavours? Give examples
.
Functional flavours are flavours that perform a specific function, such as flavour masking / enhancing / taste modifying ; or containing functional substances
<br></br>
Functional substances examples
- artifical sweeteners for calorie reduction / sugar replacement
- metal chlorides (e.g. KCl) for salt reduction
Functional flavors are ingredients that enhance the taste of food and drinks while also providing health benefits.
What is the difference between off flavours and off taints?
Off-flavours are undesirable taste / smells arising from the detioriation of the food product, while flavour tants are undesirable taste / smells caused by contamination by an external environmental source.
What are the 2 values that describes the potency of flavour compounds (odourants, tastants) and what are their equations?
- Odour activity value = [odourant] / detection threshold (conc)
- Taste activity value = [tastant] / detection threshold (conc)
Both activity values are ratios
What are the 5 basic tastes?
And the 6th and 7th basic taste?
- 5 basic taste : sweet, sour, salty, umami, bitter
- 6th basic taste : kokumi
- 7th basic taste : fat taste
Saltiness and sour taste is perceived through the activation of ____ on taste receptors.
Ion channels
sodium ions (Na+) entering the cell through channels primarily mediate salty taste, while hydrogen ions (H+) from acids entering through channels like ASICs (acid-sensing ion channels) trigger the perception of sourness
Sweetness and bitterness are perceived by ____ on taste receptors
Surface proteins
Kokumi is perceived by what receptors ?
What groups of compounds give rise to kokumi? [3]
G-protein coupled receptors;;
Compounds that give rise to kokumi : 1. Peptides & amino acids
2. Sulfur-containing compounds (in garlic, onion)
3. Lactones -> contribute to creaminess and mouthfeel (found in dairy / fatty foods)
Sweetness is most commonly associated with what group of compounds?
Simple sugars
- monosaccharides
- dissacharides
Other than simple sugars, what other classes of natural sweeteners are there? [3]
- Sugar alcohols (cooling sensation) - replace aldehyde grp of sugars with -OH
- Sweet proteins
- Glycosides -> sugar molecules that are bonded to other functional groups through glycosidic bonds
All sweet substances (steviol glycosides) produced from the stevia plant has the same sweetness and taste. True or False?
False. It depends on the number of glucose molecules present in the glycoside and location of glycosidic linkages, which can affect sweetness and bitter aftertaste.
- In general, more sugar units = sweeter and less bitter
Sugar alcohols have higher sweetness activity than sucrose (1.0). True or False?
False.
Which sugar alcohol has the sweetness closest to sucrose (1.0)?
Xylitol
All sweet proteins (100-3000) are inherently sweet. True or False?
False, sweet proteins such as Miraculin don’t have a sweet taste, but they conduct flavour modification by turning sourness into sweetness, thus increasing perception of sweetness
**Miraculin itself is not sweet. It binds to sweet taste receptors when acids are present.
This causes sour-tasting foods, like citrus, to be perceived as sweet. **
Artificial sweetners have ____ sweetness intensity than sucrose (1.0). state the values too.
Higher
- 200 - 20,000
What are some key differences between artificial sweeteners and natural sweetners, orther than sweetness activity? [4]
Artifical sweetners …
1. Lower in calories
2. Lower GI (as they are not digested)
3. Have a different mouthfeel
4. Have undesirable bitter aftertaste
List some examples of artifical sweetners. [6]
1.Cyclamate
2. Acesulfame potassium (Ace K)
3. Aspartame
4. Neotame
5. Saccharin
6. Sucralose
CAANSS
Sour taste is usually associated with what class of compounds?
Organic aicds
Which organic acid is the gold standard for sourness in the food industry?
Citric acid
Phosphoric acid is used as an acidulant in what applications?
Beverages (soft drinks)
Saltiness is usually associated with what compound?
- Sodium (sodium chloride)
What other substitutes can be used as salt (NaCl) replacers? [2,4]
- Metal chlorides (KCl, CaCl2)
- Metal sulfates (Na+, K+, Mg2+, Ca2+)
What is the advantage and disadvantages of using KCl as a salt subsititue?
Advantage : reduce sodium intake, and increase potassium intake, in which many people are lacking. (reduced sodium also means reduced risk of hypertension)
Disadvantages :
1. lower saltiness (0.6)
2. bitter aftertaste
Bitter substances are associated with what kind of compounds? [3]
- bitter AA / peptides (hydrophobic)
- Polyphenols (tannin)
- Alkaloid (caffeine)
Umami / savoury substances are associated with what types of compounds? [3]. Give examples where applicable
- Peptides
- Amino acids (glutamate, MSG)
- Nucleotides : Guanosine monophosphate (GMP), inosine monophosphate (IMP)
Note : glutathione is a kokumi peptide, nit umami!
Trigeminal sensations: 1. Astringency 2. Cooling sensation 3. Hot / pungent / spicy / tingling
