NUTR 320 Exam 1

Water function

* Heat transfer
* Solvent (can dissolve solutes)
* Chemical reactions (ionization, etc)
* Microbial growth (helps microbes survive – bad)

Carbohydrates function

* Saccharides: sweetness, solubility, crystallization, color, moisture absorption, texture, fermentation, preservation
* Starches: thickening agents, edible films, sweetener source (syrups)
* Fibers: thickeners, gelling, stabilizers, emulsification, add body, texture, and impart mouthfeel

Lipids/oils Function

* Heat transfer during food prep
* Add tenderness
* Emulsifier (brings oil and water together, no separation)
* Add texture, add flavor
* Noncooking feature: satiety

Proteins Function

* Hydration
* Denaturation/coagulation
* Enzymatic reactions
* Buffering
* Browning

Vitamins/Minerals Function

* Sodium: add flavor and perspective
* Improve shelf life (antioxidants)

What are processed foods and what are the positives and negatives of them?

Any food that has been intentionally modified in some way before eating

* Positives: add flavor and nutrients, convenience, and increased shelf-life
* Negatives: loss of essential nutrients in some processed foods, the addition of less healthy nutrients

5 categories of processed food and example for each

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1. Minimally processed (example: cut broccoli)
2. Processed for preservation (example: canned green beans)
3. Mixtures of ingredients (foods with ingredients added for flavor and texture)
4. Ready-to-eat foods (example: cereal)
5. Convenience foods (pre-made meals – example: frozen pizza)

What are food additives

Any substance the intended use of which results or may reasonably be expected to result, directly or indirectly in it becoming a component of otherwise affecting the character of the food

Positives of food additives

* Maintain or improve safety and freshness
* Improve or maintain nutritional value
* Improve taste, texture, and appearance
* Extend storage life

Natural definition

What questions do the USDA ask?

* Has no official definition in the US except when it is used to describe meat, poultry, and eggs monitored by USDA

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1. Does the product have artificial or synthetic ingredients?
2. Are the product and ingredients only minimally processed?

FASTER ACT

* food allergy safety, treatment, and education and research act
* Law requires food manufacturers to specify ingredients that are major food allergens on the labels of packaged foods and beverages
* FDA enforces regulations that require food manufacturers to prevent allergen cross-contact

How many allergens are required on food labels and what are they

1. milk
2. eggs
3. fish
4. Crustacean shellfish
5. tree nuts
6. peanuts
7. wheat
8. soybeans
9. sesame

What are added sugars

Sugars that are added during the processing of foods, or are packaged as such and include sugar (free, mono, and disaccharides), sugars from syrups and honey, and sugars from concentrated fruit or vegetable juices that are in excess of what would be expected from the same volume of 100% fruit or vegetable juice of the same type

Solution

Colloidal dispersion

Coarse dispersion

Dissolves (

Solution definition

* The maximum amount of a solute that can dissolve in a solvent or liquid at a given temperature
* Solutions are a solute that is equally dispersed in a solvent

Solute different level of saturation

1. Unsaturated solution: not everything is mixed (example: iced tea with sugar sinks to the bottom)
2. Saturated solution:\*
3. Supersaturated solution\*

Saturation and temperature relationship

* The saturation of a solution depends on the temperature
* The higher temperature, the more of the solute can be mixed

What is a colloidal dispersion

Two-phase system containing at least one colloid 

What is a coarse dispersion and examples

A mixture of substances with particles larger than a “colloid”

Examples: oatmeal flakes in water, an uncooked starch mixture

Heat energy and it’s units

A mixture of substances with particles larger than a “colloid”

Unit: Calorie or Kilocalorie

Kilocalorie

Amount of energy needed to raise 1 kg of H2O by 1 degree Celsius

How is water moved between it’s three states

Energy is added or removed

What is the physical state of water (liquid)

* Range of temperatures
* What are the molecules like
* Specific heat

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* 39 - 212 degrees Fahrenheit
* Water molecules bounce around (covalent bonds joining and breaking)

The rate of joining and breaking of hydrogen and water molecules depends on the temperature
* High specific heat: 1 (takes a lot of energy to move water into its different states)

Freezing point

temperature at which a liquid becomes a solid

* 0 degrees Celsius/21 degrees Fahrenheit

Question #1: When water goes from free water to ice.  Energy is:

A.    Added

B.    Removed

B. Removed (use 80 calories)

Question #2: When water goes from ice to free water.  Energy is:

A.    Added

B.    Removed  

A.    Added (add 80 calories)

Boiling Point and what is the temperature of boiling point at sea level

the temperature at which a heated liquid begins to boil and changes into a gas

* 212 degrees Fahrenheit and 100 degrees Celsius

What happens to the “heat” (or energy) as water turns into steam?

540 calories of energy are added

How much energy is added to convert water to steam?

A.    80 calories

B.    212 calories

C.    540 calories

D. 850 calories

C.    540 calories (so high due to gravity)

Factors that Effect Freezing Point

* Solutes alter the temperature at water freezes and the time it takes a substance (e.g., foods) to freeze.
* Salt: decreases the freezing point of water
* 32 degrees Fahrenheit to -21 degrees Fahrenheit
* Frozen desserts: sugar and fats interfere with ice crystal formation

Factors that Alter Boiling Point (BP)

Air pressure

Altitude

How does a pressure cooker work

Increases temperature in which foods are cooked, hard seal prevents steam from moving (temperature ends up higher than boiling)

True or false:

Cooking food at a higher altitude take longer

True

True or false:

Boiling points are not affected by addition of solutes

False

Functions of water in food preparation

Heat transfer & Freezing

Solvent

* Dispersions

Chemical reactions

* Ionization
* Salt formation
* Hydrolysis
* Carbon dioxide release
* Changes in pH
* Water activity

Ionization

* what is it
* example

* Solute/ Neutral molecule separates into two electrically charged molecules: Table salt: NaCl → Na+ + Cl-
* Salt is added to different foods to dissolve and change product

Salt formation

* example

* As a solvent, water allows neutrally charged and positively charged particles to join
* Electrolytes, metals, acids, and bases

Acids

* PH range
* proton donors or acceptors
* taste
* example
* what kind of pan can change their flavor and color

* Less than 7
* Proton donors (H+)
* Sour taste due to excess hydrogen ions
* Examples: lemon juice, lime juice
* Copper pan

Bases

* PH range
* proton donors or acceptors
* taste
* example

* greater than 7
* Accept protons (OH-)
* Bitter or soapy taste
* Examples: old eggs, baking soda

Is the water from a tap more basic or acidic?

basic

Examples of food/drink changed to be more basic

* Coffee with distilled water makes it more neutral
* Kombucha used distilled water for more neutral, helps with fermentation

Hydrolysis

* examples

* Breakdown large molecules into smaller ones due to the addition of water
* cornstarch in corn syrups, protein into hydrolysates, foaming abilities, create new sugars used for candy making, smaller compounds add flavor to food

Carbon Dioxide Release

* where is it seen
* examples

* Seen in baked goods that need rise
* Examples: Yeast bread (fermentation produced CO2), Quick bread (muffins, pancakes - addition of chemical leavening agents with water produces CO2)

Water activity (aw)

* what is it
* what does it determine
* how to lower water activity

* The measure of free water
* Determines a food’s perishability
* drying, freezing, adding salt or sugar, adding additional preservatives

Heat transfer

* How energy is transferred from the source (gas, electric, wood, charcoal) to the food
* Heat source → Molecules vibrate rapidly → transfer new energy to a new system

Radiation

* what is it
* example

* direct transmission of energy in the form of electromagnetic (non-ionizing) waves
* microwaves

Induction

* what pans work
* what does it lessen

* electromagnetism to transfer heat to a neighboring material
* only cast iron or those made of stainless steel
* Lessens hot spots

Conduction

* examples

* direct transfer of energy of molecules from one system to the molecules in another system that it is contacting
* Examples:
* Heat in the metal of a pan/pot → liquid in the pan or food in contact with the pan
* Heat in the metal of a grill → food in contact with the grill
* Heat in the liquid → food in contact with the liquid
* Heat on the outside of a food moving → inside of the food

Convection

* examples

* movement of currents of hot air or liquid (water/oil) in a circular motion
* oven, simmering/boiling, steaming, deep frying

Air frying

* Use convection to rapidly circulate hot air to cook food at high temperatures
* The outside becomes crispy – like frying does
* Machine Shapes: small pods or square/rectangular-shaped
* Convection toaster ovens are “air-fryers”

What does cooking do to food

Alters molecular interactions & speeds chemical reactions

* Foods become more palatable
* Preserve food
* Irreversible

Cooking temperatures

•   32°F – freezing point

•   140°F – Maillard reaction can occur

•   145°F – Medium-rare steak

•   150°F – Medium well steak

•   160°F to 180°F – Egg proteins fully coagulate

•   212°F – boiling point of water

•   230°F to 400°F – Caramelization (depending on the sugar) 

•   250 to 300°F – temperature see Maillard reactions at faster rate

Taste

relies on signals to the brain that relay the sensations of sweet, bitter, sour, salty, and umami

Flavor

The combined sense of taste, odor, and mouth feel

* Includes many compounds, most are aromatic compounds

 

Taste buds

* location
* amount
* do they change with age

* Taste buds found on the tongue, mouth palates, and the pharynx
* 9k to 10k taste buds
* Atrophy with age

Where are taste buds located on the tongue

* fungiform papillae
* foliate papillae
* vallate papillae

Sweet taste

* organic or inorganic compounds
* name all 4 and examples

* organic compounds


1. Saccharides
2. Specific amino acids 

* Glycine, alanine, some other
* Combined: example - phenylamine and aspartate


3. Sugar Alcohols

* Xylitol, sorbitol, mannitol


* OH group replaced (=O+)


4. Aldehydes

* Cinnamaldehyde

Sour taste

* what does the degree of acidity depend on
* examples

* depends on the hydrogen ion concentration, molecule weight, size, and polarity
* Examples:


1. Lime/lemon juice (citric acid)
2. Vinegar
3. Most fruits have organic acids (citric, malic, tartaric)

Salty taste

* what causes it
* difference between NaCl and KCl

* presence of cations and anions


* NaCl - Sodium Chloride (table salt)
* KCl - Potassium chloride (salt substitutes) (little bitterness)

Umami taste

* what nucleotide causes the flavor-enhancing
* examples
* what salt causing the flavor enhancing

* Flavor-enhancing nucleotide: glutamates
• Naturally in seaweed, fish, meat, mushrooms, tomatoes, carrots, potatoes, cabbage, aged cheese (parm)
* Flavor enhancing salts
• MSG (Monosodium L-Glutamate)

Bitter taste

* what causes it
* examples

* alkaloids in foods
* examples:

•       Caffeine

•       Quinine

•       Theobromine

•       Nicotine

•       Humulone (hops) - beer

•       Polyphenols/Flavonoids  - wine, tea

Odor

* what is it dependent on
* what does heat cause
* what kind of molecules are more volatile and example

* Odor is dependent on molecule volatility
* Heating causes volatile molecules in the food to be released
* Smaller, lighter molecules are more volatile (hot coffee vs. iced coffee – smell hot coffee much more)

Mouthfeel

* examples

Textural qualities of a food or beverage perceived in the mouth

* Moistness or dryness
* Softness or crispiness/crunchiness or toughness
* Viscosity (thick/thin)
* Astringency
* Temperature (hot, cold, spicy, cooling)
* Grittiness, stickiness, hardness, tingling

Factors that Influence Taste (and flavor)

* The preconceived idea of what the taste should be
* Previous unpleasant experience
* Exposure to foods
* Absence or diminished smell
* Hot and Cold

\- Temperature: ideal range 68-86 degrees Fahrenheit

\- Burning sensation (spice level)

\- Cooling: menthol, camphor, sugar alcohols (xylitol and erythritol)

Taste Sensitivity (Perception)

Minimum concentration at which an individual can detect a taste or flavor

Threshold Concentration

The concentration of a taste compound at a barely detectable level

Subthreshold Concentration

Taste compounds are below threshold concentrations, but they influence other taste perceptions

Acid effect on taste perception

Enhances saltiness perception

Reduces sweet perception

Salt effect on taste perception

Enhances acidic and bitter perception Enhances the sweetness perception

 Sugar effect on taste perception

Reduces bitter, salty, acidic, and spicy perception

 Fat effect on taste perception

Reduces acidic perception

Factors that influence taste sensitivity

* Time given given to “tasting” a substance
* The concentration of the substance generating the taste
* Genetics: Individuals’ ability to detect various tastes


1. The number of taste buds and trigeminal nerve endings a person has
2. The sensory capacities of those taste buds and trigeminal nerve endings
3. The response of the brain to signals from taste buds and trigeminal nerve endings

Ways to test sensitivity threshold

* Genetics of sensory thresholds:  Phenyl Thio Carbamide (PTCB)
* Number and shape of fungiform papillae

How a nutrition professional thinks about food

* Nutrient content
* Weight management
* Disease prevention and management
* Inflammation
* Microbiome
* Athletic performance
* Food allergies

How a consumer thinks about food

* Taste
* Price
* Healthfulness (Weight Management/Dz prevention) 
* Convenience
* Environmental Sustainability

Basic principles of building flavor profiles

* Consider appearance, aroma, taste/flavor, and mouthfeel
* Every ingredient should have a purpose
* Ingredients can work together by harmonizing or contrasting
* When using contrasting ingredients, make sure they balance  
* Consider other items served with the dish you are preparing

Cooking Aromatics

* what are they
* examples
* how it it cooked

* Vegetables that deliver flavor and aroma when heated or crushed and serve as the foundation for recipes.
* Examples: onions, garlic, chilies, celery, leeks, bell peppers, carrots, ginger, etc.
* Typically heated in oil or butter (fat)as the first step.

Seasoning

* Examples

Any compound that enhances the flavor already found naturally in food

Examples:

* Onions, garlic, shallots
* Herbs and Spices
* Salt and salt substitutes
* Pepper
* Condiments (ex. Worcestershire sauce)
* Grated lemon/orange rinds
* Vinegars/juices (lemon/lime)
* Prepared mustard
* Wine/Brandy/Bourbon (others)

Flavoring

* Examples

Any substance that adds a new flavor to food

Examples:

* Wine/brandy/bourbon
* Flavor enhancers
* Oil extracts
* Marinades
* Rubs and pastes

What is the difference between an herb and spice?

Herb is from leaf/stem and spice is from root/bark/seed

Non-enzymatic browning

* what is it
* examples

Browning occurs without the need for enzymes

Examples:

* Millard reaction
* Caramelization

Enzymatic browning

Enzymes break down phenolic compounds in fruit/veg

Maillard Reaction

* foods that undergo this reaction

the browning reaction that occurs when sugar (free or bound in starch) and protein are heated or stored over a length of time (all sugars reduce but sucrose)

* potatoes, vegetables, turkey/beef, baked goods

Cooking techniques to create the Maillard Reaction

\-        Baking, roasting, grilling, pan-searing, frying, broiling

* browning meats: steak, roasted meat
* vegetables with protein: roasting, pan-frying, deep frying

 Acrylamides

carcinogenic compounds that occurs when heat is very high

Caramelization

* foods that undergo this

melting and oxidation of sugars at a high temperature resulting in a nutty, complex flavor and brown color (NO PROTEIN OR AMINO ACID NEEDED

* crème brulee

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* 300 – 400 degrees F
* Fructose: 230 degrees F
* Galactose/glucose: 320 degrees F
* Sucrose: 338 degrees F
* Maltose 356 degrees F
* Lactose 397 degrees F

Caramelization Reaction

* Cooking techniques to create this reaction

At high heat, sugars dehydrate, break apart & polymerize into various aromatic compounds

* high heat application in baking, pan-frying, roasting, pan-searing

Aromatic compound examples

* alcohol, acetaldehyde, acetic acid, diacetyl, ethyl acetate, furan, benzene, maltol

Foods that participate in both caramelization and Maillard reaction

* roasted carrots
* caramelized onion
* Presence of protein, sugar, and temperature determines which it is

Enzymatic oxidative browning

* examples

Enzymatic oxidative browning darkens vegetables and fruits exposed to oxygen

Examples:

* Avocado – phenols
* Apples – quinones
* Potato – melanins

Salt

* percent of sodium vs. chlorides
* how often it is used
* which salt is fortified
* what is it first used as

* 40% sodium, 60% chloride
* 2nd most frequently used food additive
* iodized salt is fortified
* first used as a preservative

Table salt

* amount of Na mg per 1/4tsp
* does it have iodine
* examples of when it is used

* 590 mg Na (1/4 tsp)


* yes
* Examples: Soups, stew, braising, baked goods (yeast bread)

Kosher salt

* amount of Na mg per 1/4tsp
* does it have iodine
* examples of when it is used

* 500mg Na (1/4 tsp)
* no iodine
* Cooking that uses minimal liquid: Rubs, marinades, pastes

Sea salt

* amount of Na mg per 1/4tsp
* does it have iodine
* examples of when it is used

* 400 - 500 mg Na (1/4tsp)
* Trace amounts of iodine, Mg++, K+, Ca++
* Finishing salt

Himalayan Salt

* amount of Na mg per 1/4tsp
* does it have iodine
* examples of when it is used

* \~400 mg Na (1/4 tsp)
* Trace amounts of iodine, Mg++, K+, Ca++
* Finishing salt

What do pepper berries color depend on?

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ripeness

What is the chemical in black pepper

piperine

Red Pepper (or Cayenne)

* what family
* what is the chemical in red pepper

* Same family as chiles, paprika, and bell peppers
* The chemical in red peppers is “capsaicin” which can cause a burning sensation of the hands