Flavor and Texture Flashcards
Recognize characteristics of and factors that affect food flavors
1) Includes: taste and aroma
2) Very subjective – taste and smell affect individuals taste experience
3) Influenced by
- Bacteria, yeasts, molds
- Enzymes
- Temperature
- Moisture
- Light
- Time – flavor compounds can deteriorate over time
- Additives
4) Substances that produce taste are water soluble
- Taste is just one component of flavor
Distinguish between the 6 different tastes and identify substances contributing to those tastes
1) Sweet – sugars, alternative sweeteners (aspartame, sucralose, saccharin, etc.), sugar alcohols
- Preference for sweet taste is innate (we are born with it) > could be because sweet foods have calories versus sour does not
2) Sour – acids (i.e. lactic acid)
3) Salty – NaCl (sodium chloride), KCl (potassium chloride)
4) Bitter – alkaloids (nitrogen containing compounds) like quinine, caffeine
5) Astringent – polyphenols (in fruits and vegetables), tannins (in tea and coffee and wine)
- More of a sensation than a taste
6) Umami – dinucleotides and glutamate (amino acid) that gives food the umami taste
- Mushrooms, broths, things with MSG
Describe pungency and identify substances that contribute to pungent foods
1) Pungency
- warming or hot sensation in mouth and lips
- pungent foods cause release of endorphins
- capsaicin - chilli peppers
- gingerol
- piperine - black pepper
- Isothiocyanates - horseradish and mustard
- sulfur-containing compounds - onions and garlic
- potency measured in Scoville heat units or with HPLC
- Scoville - more for capsaicin content (subjective test)
- HPLC (high pressure liquid chromatography) - objective; measures amount of these compounds in parts per million
Substances that contribute to cooling sensations
1) Menthol (mint)
- baked goods
- gum
- candy
- frozen desserts
- beverages
2) sugar alcohols
- found in sugar free gum, sugar free mints, diet beverages (cooling sensation in addition to being a sugar replacer)
Explain the chemical reactions that produce flavors and the conditions under which they produce flavors
1) Duration and temperature of thermal processing affect flavor
2) Chemical reactions produce flavor
3) Nonenzymatic browning (produce color AND flavor changes)
- Maillard reaction – pyrazines (these compounds produce flavors)
»> Pyrazines – created in second step of maillard. Contribute to aroma and flavor
- Caramelization - diacetyl, esters, lactones, furans, maltol (nutty, butterscotch, rum, toasted flavors from these compounds)
4) Fermentation - sugar alcohols and acids (makes more sour i.e. sourdough bread)
- Typically less sweet and more sour compared to what it was before fermentation
5) Meat flavor - maillard reaction, fat, sulfur containing compounds
6) Enzyme-produced flavors
- From yeast, micro bacteria, molds
- Flavors vary based on enzymes
Describe the processes that produce flavors and the flavors they produce
1) Producing flavors (things that are used to flavor foods)
- Natural and artificial flavors
- Essential oils (plants or herbs) (lipid soluble)»_space;> Very similar to oleoresin
- Extracts (uses alcohol as solvent to extract flavor) (water soluble)»_space;> Vanilla and almond extract are sweet without a sugar
- Oleoresin – oil soluble compound obtained from spices or herbs. Paprika one most used, used more for coloring (lipid soluble)»_space;> Very similar to essential oils
2) Process flavors – generated by heating mixture of ingredients (one containing nitrogen and another a reducing sugar)
3) Reaction flavors – produced by reactions under controlled conditions
- pH
- Water activity
- Temp
Recognize substances that enhance flavors
1) Protein hydrolysates
- Ie whey (also soy, and casein)
- Also add protein, increase nutritional content, improve flavor
2) Flavor encapsulation – stability and timed release
- Flavors in an encapsulated form > enhances flavor and provides stability
- Coating composed of maltodextrin, modified starch or gums
- Barrier to heat, acid, oxygen, and moisture
3) Taint: results from external contamination
Substances that produce off-flavors
Off-flavor: (produced intrinsically > something internal going on)
1) Aldehydes, ketones, alcohols – rancid smell and taste (when an unsat FA is oxidized)
2) SCFAs – rancid flavor (butter); beany flavor (soybean)
- Butter > due to hydrolytic rancidity
3) Maillard intermediates – cooked
4) Phospholipids –warmed over flavor (WOF) > in meats; it’s the flavor that is produced when meat is reheated
5) Putrescene – putrid, rotting
6) Trimethylamine – fishy
- Trimethylamine oxide is converting trimethylamine when fish is captured
7) Sulfur compounds – burssel sprouts, broccoli egg yolks > can put off an off-flavor when not cooked well
Recognize the causes of warmed-over flavor (WOF) and ways to minimize WOF
1) Stale taste in reheated meats
2) Iron-catalyzed oxidation (in meats that contain myoglobin)
3) Meats with high phospholipid or unsaturated fatty acid content
- Oxidation of phospholipids and unsaturated fatty acids
- i.e. Red meats contain most myoglobin; but beef and lamb are less susceptible to WOF because less unsat fatty acids, but pork has more unsat fatty acids and is more susceptible
4) Minimizing WOF
- Nitrates
- Antioxidants (ascorbic acid helps prevent oxidation) > because it is an
- Wrap tightly
- Eat asap and reheat quickly > quick reheating oxidative process
»> sooner you eat the leftovers, the better
»> The oxidation process starts right when you cook and so the oxidation process will continue the longer you keep in the fridge
5) Mostly in pork and dark meat poultry (because has more unsat FA in comparison
to beef and lamb)
8) Describe food texture and how it is evaluated
1) Physical property
2) Perception of food structure when touched, pushed by tongue or chewed by teeth
3) Determined by microstructure of plant and animal tissue
4) Influenced by texturizing ingredients
5) Evaluated by
- Sensory perception (subjective)
- Mechanical testing (objective)
6) Mouthfeel (subjective)
Define mouthfeel, rheology and viscosity
1) Texture measurement determines
- Food structure
- Resistance to shear force (cutting force) or applied force (change in shape, indentation > deform the food but not cut through it)
2) Mouthfeel - Not same as texture but used to describe texture – includes initial sensation when food enters mouth and when swallow (texture more how feels when moves around in mouth and when is chewed)
3) Rheology – study of flow of matter in response to force
- How a fluid will pour
- How a fluid will be sensed by tongue
- How long it takes for fluid to be cleared from palate
4) Viscosity – resistance to flow
- The more viscous it is (the more thick it is) the more resistant it is to flow
- Affected by temp > heating decreases viscosity
- Heating something makes it less viscous
Identify mechanical characteristics of solid and semisolid foods
1) Cohesiveness (ability to stay together) and chewiness – tender, chewy, tough
2) Fracturability – force at which solid food split (shear force)
3) Hardness – soft, firm, hard
4) Elasticity – returns to shape when force removed
5) Plasticity – force produces impression that doesn’t spring back
11) Recognize the influence of moisture, water activity and fat crystallization on food texture
*Water-based systems
1) Moisture and water activity influence texture
2) Hard texture – low moisture and low water activity, associated with
bound water
3) Firm texture – low moisture, higher water activity, associated with adsorbed water
4) Soft texture – high moisture and high water activity, associated with free
water
- Fat-based systems
1) Consistency of fat is due to organized 3D network of solid fat crystals embedded in oil
2) Soft texture depends on: - Size, shape, and stability of the fat crystals > all of these can affect texture
- (Crystal network of fat in foods can effect texture)
Describe the functions of texturizing agents
1) Promote viscosity (make fluid more resistant to flow)
- Typically the ones that promote viscosity typically don’t form
gelation
2) Increase firmness
3) Cause gelation
- The ones good at forming gels are not good as thickeners
Describe the chemical and functional properties of carbohydrate- and protein-based texturizing agents: Sugars and polysaccharides
- Sugars - firm texture, viscosity > because sugar adsorbs water
- Sugars inhibit gelatinization and gelation (contribute to viscosity) > sugars
compete with starch for water and starch is what you need to gelatinize
objects > sugars work well with acting as thickeners
- Polysaccharides – viscosity or gelation, mouthfeel
1) High amylose starches are better for gelation > amylose leaks out of cell and reorganizes
2) High amylopectin starches are better for viscosity
3) i.e. high inulin is good for gelation, low inulin good for viscosity
4) Gums, cellulose derivatives gels > can be used as fat replacers because
they mimic the mouthfeel of fat
