Modules 7-12, Culinary Chemistry Exam 2!!

Hydrogenation

- Adds hydrogens across the double bond, transforming an unsaturated fatty acid to a saturated one - NOT truly saturated, forms trans fats that are very firm and can cause health problems

Herve This

- Began molecular gastronomy - Physical chemist who had a souffle disaster in his kitchen

Metabolizing alcohol

- Broken down in the stomach and liver - Women generally retain alcohol more than men - Genetics plays affect to alcohol handling

Maillard reaction

- Browning reaction - Carbohydrate and amino acid form unstable intermediate, then hundreds of by-products result - Due to amino acids in proteins

Spherification

- Calcium chloride ions cause the alginate polymers to become cross linked, creating a gel

Properties of alcohols

- Clear liquid at room temperature - Less dense than water - Boils at a lower temperature than water - Dissolves in water - Flammable

Supersaturated

- Contain more dissolved sugar than it could normally at this temperature - The smallest disturbance will induce sugar crystals to form and grow

Sous Vide cooking

- Cooking through air that is set at constant temperature - Repeatable, and can leave food in appliance and it won't overcook

Best material to use for cooking

- Copper - Excellent heat conductor - Highly reactive with acidic or basic foods, usually lined with tin or stainless steel to make it non reactive

Conduction

- Direct transfer of heat - Heat conducts in food towards the center - Food behaves more like an insulator than a conductor

Ethanol

- Drinking alcohol, CH3CH2OH - All other alcohols are toxic including methanol (CH3OH) which causes blindness

Flash Freezing

- Food exposed to extremely low temperatures - Causes outside to become frozen with liquid center - Liquid nitrogen

Distillation

- Goes from liquid to vapor to liquid again - Purifies and separates liquids

Radiation

- Heat in the form of waves - Considered thermal radiation, does not require contact between food and heat source

Convection

- Heat transfer through fluids - Can be water, oil, or air - Combines conduction and mixing

Induction

- Heat transfer through magnetism - Alternating current causes rapidly changing electromagnetic field - Most efficient way to convert energy to heat on a cooktop

Free Radicals

- Highly reactive compounds - Formed naturally and are important for normal cellular processes; however cause cell damage in high concentrations - Contain a single electron

Health benefits of alcohol

- Lower chance of death from heart disease or stroke - Helps limit blood clots and high colestorol - Antioxidant source (red wine) - Lowers the chances of arthritis and certain cancers

Cooking with alcohol

- Marinating proteins in wine help lock in moisture - Alcohol contributes distinct flavors - Hydrophobic ends dissolve compounds water cannot

Rancidity

- Saturated fats are more stable and slower to become rancid than unsaturated fats - This is because the double bond on a carbon opens up a small space for molecules such as oxygen to invade and break the chain

Saturated vs Unsaturated

- Saturated means it is filled to the capacity with hydrogen bonds, meaning there are no double bonds - Unsaturated compounds have one or more double bonds between carbons

Carmelization of Sugar

- Simplest browning reaction - When sucrose (sugar) is heated - Will deepen to dark brown because of sour organic acids and brown-colored polymers

Vegetable Texture

- Sodium and Potassium ions give rise to softer veggies - Calcium and Magnesium cross link with pectin molecules to produce firmer veggies

Cold water test

- Test used before thermometers - Thin syrups will form a thread in the air - Concentrated syrups form a soft, malleable ball - As the concentration increases, the cooled ball becomes harder

Searing meats

- The sizzle comes from a droplet of water making contact with a very hot metal - Searing meats actually causes the meats to lose more moisture than not searing - The moisture comes from the meat

Vegetable Carbohydrate sources

- beans, peas, corn, and potatoes - Veggies in general are a good source of fiber, minerals, and vitamins

Antioxidants

- neutralize free radicals by donating an electron - Come from vitamins

Specific heat capacity

- the amount of energy needed to raise the temperature of one gram of a substance one Kelving - Cheese > Sauce > Crust

Yeasts

- unicellular fungi - Convert sugar into alcohol, CO2, and other flavors

You consume an antioxidant capacity of 1967 when eating a red delicious apple. How much of the apple did you consume?

1/3 of the apple

Veggie pH

5-5.6

Calculate the antioxidant capacity of a salad made from ½ cup cranberries and ¼ oz pecans.

5765

Gay-Lussac's Law

As temperature increases, pressure increases

Charle's law

As temperature increases, volume increases

Other than fruits, vegetables, and nuts, what are some other sources of antioxidants?

Coffee, Green tea, Red wine, Dark chocolate, Certain spices

When one substance is evenly dispersed in another substance, you have a:

Colloid

Water, ammonia, and salt are all ______________ that are combined in definite proportions

Compounds

When grilling, what types of heat transfer can occur?

Convection and radiant

Interfering agents

Corn syrup also provides body and chewiness, is less sweet than sugars, and has the advantage for manufacturers of being less expensive than crystalline sugar

Conduction Cooking Style

Correct match:direct contact with heat

Order each of the following from strongest intermolecular force to weakest Strongest

Covalent Ionic Hydrogen bonding Van der Waals

Cause of free radicals

Environmental toxins such as cigarette smoke, radiation, pollution Also produced from oxidation

Discoloration Cause

Enzyme activity

Radiation

Heat in the form of waves

Conduction

Heat is transferred through direct contact with the heat source

Induction

Heat is transferred through magnetism

Convection

Heat is transferred through the movement of fluids

Vitamin C

Helps build connective tissue

Heat vs Temp

Temperature measures the average energy of each atom; heat is the total for all the atoms Average income of US household vs. total wages in the US

Since fats melt at a higher temperature than oils, what do you know about the total strength of the bonds in fats vs. oils?

The bonds are stronger between fat molecules than between oil molecules.

Sugar concentration vs boiling point

The higher the sugar concentration, the higher the boiling point

Sugar concentration vs texture

The lower the sugar concentration, the softer the final product will be

Resonance

The movement of electrons in double bonds to stabilize free radicals

Sweetness vs alcohol content

The sweeter the wine, the lower the alcohol content This is because the sugar from the grape converts itself to alcohol

Smoke point

The temperature at which a fat breaks down into visible gaseous products

All of the following is true about the bonds that hold fats together except:

These types of bonds are always weak, no matter how many there are

All of the following is true about the bonds that hold fats together except:

These types of bonds are always weak, no matter how many there are.

What properties do antioxidants have? Choose all that apply.

They have multiple double bonds, They can come from nuts, They are stable when in the radical form due to resonance.

A confectioner can boil a sugar syrup solution until a desired temperature is reached, which indicates the concentration of the syrup.

True

Acids are added to carbonated beverages to help keep CO2 in solution.

True

All candies are essentially a mixture of two ingredients: sugar and water.

True

Although ceramics are poor conductors, they are a versatile type of cookware.

True

Antioxidant free radicals are more stable than the radical that formed them.

True

Antioxidants donate an electron to make an unhealthy cell healthy again.

True

As a water boils (goes from liquid to gas) the temperature does not change.

True

Based on Henry's law, the higher the pressure of the gas above a solution, the higher the concentration of gas in solution.

True

Boiling foods occurs at a temperature lower than needed for browning reactions to occur.

True

Brittles are different than other hard candies because they contain butter and milk solids

True

Candies can be coated in a pan-hard panning-by spraying a sucrose syrup on the candy and allowing the water to evaporate.

True

Candy canes have bubbles and sugar to give them a crisp texture.

True

Candy texture is influenced by the concentration of the sugar in the syrup.

True

Cast iron materials work great in high temperature cooking.

True

Ceramics are poor conductors; both carbon steel and cast iron are reactive with acid and basic foods; copper provides the best conductor, while stainless steel is unreactive.

True

Certain foods have additives that behave as antioxidants, keeping the food fresher longer.

True

Certain types of cooking, such as boiling, do not allow browning reactions to occur because they do not get hot enough.

True

Complex disperse systems are simply mixtures of more than two phases.

True

Convection occurs between any type of fluid: water, oil, air, smoke.

True

Cooking a material through the use of a fluid is called convection.

True

Cooling with help preserve the freshness of most vegetables.

True

Copper is an excellent conductor and is non-reactive with food only when coated with tin or stainless steel.

True

Disrupting the tubulars of potatoes can cause discoloration due to enzyme activity.

True

Distillation is the separation of liquids based on the differences in boiling point.

True

Electrons are loosely held in metals, allowing them to conduct heat.

True

Even though radiation occurs in all types of cooking, only radiation at high temperatures is a useful type of heat transfer.

True

Free radicals attack healthy, living cells.

True

Free radicals represent a single electron and are formed from breaking weak bonds.

True

French fries are vegetables!

True

Fudge is a more complex crystalline candy because they syrup also carries milk solids and fat droplets.

True

Gases readily mix together regardless of the composition of the gas.

True

If the amount of gas increases the volume of gas increases.

True

Maillard reactions occur between a carbohydrate and an amino acid.

True

Microwaves cause water molecules to move faster, heating up the food.

True

Nonmetallic solids are great insulators, but are not good conductors.

True

Oxidative stress is caused by the cascading of free radical formation.

True

Pan frying works best with leafy green vegetables.

True

Pan-frying allows for browning reactions to occur due to the high temperature cooking.

True

Pressure cookers increase the pressure, allowing food to cook at a higher temperature.

True

Radicals are more stable if they have more carbon groups attached to them.

True

Rancid fats come from the decomposition of fatty acid chains of triglycerides.

True

Resonance is the movement of electrons in double bonds and it helps stabilize unstable free radicals.

True

Rock candies are made by slowly growing crystals out of a supersaturated solution

True

Saturate fats and hydrocarbons that are saturated with hydrogens.

True

Solutions can be created by mixing gas in to a liquid.

True

Spherification is used to create liquid spheres that "explode in your mouth."

True

Sugar molecules will bond together in orderly arrays.

True

Temperature and pressure are directly related.

True

The "hardness" of your cooking water can effect the flavor, texture and color of your vegetables.

True

The fruit in wine is concentrated when cooking to provide more flavor to the dish.

True

The main difference between beer and wine is what the yeast consumes to produce the alcohol.

True

The smoke point of oils can limit the temperature at which foods can be cook in certain fats and oils.

True

The solubility of gases in liquids increases as the temperature decreases.

True

Trans fatty acids are double bonds that have the chains extending from either side of the double bond, forming a "z" type shape.

True

Unsaturated fats contain at least one multi (double or triple) bond.

True

Vegetables are a better source of vitamins and minerals then fruit.

True

Vegetables cook right after harvest have more flavor then store bought vegetables.

True

Water hardness is the presence of Mg, Ca and other metal ions in your water.

True

When a free radical is produced, it causes the production of other free radicals due to the instability of the radical.

True

When alcohols are distilled, they turn into a vapor, then condense into another container.

True

When something boils at a lower temperature, it takes longer for the food to cook completely.

True

When sugar is caramelized, the taste, smell, and color changes.

True

While non-stick aluminum is both conductive and non-reactive with food, it can only be used up to certain temperatures.

True

Wooden spoons can help prevent premature crystallization.

True

How to prevent crystallizatoin

Use wooden spoons, avoid agitating the syrup once it is finished cooking and is cooling, remove dry spatter from walls of pot with a moist brush

Equipment for a molecular gastronomist

Vacuum machine, hypodermic syringe, liquid nitrogen, anti-griddle, and the gastrovac

Strength of bonds

Van der Waals< hydrogen bonds< ionic bonds< covalent bonds

What influences the texture of candy

Varying the proportions of water and sugar and how the candy is cooled

Steak sizzle

Water and proteins coming out of the meat and hitting the pan

Omnipresent steam

Water vapor coming off a steak

Beer ingredients

Yeast, barley, hops, and water - Barley is the seed of grain - hops are a pine-cone like flower, a member of the hemp family

How alcohol is made

Yielded from microscopic yeasts Sugars break down into alcohol molecules

Milk proteins are added to candies: to thicken the candy body, to add a rich flavor

a and b

Antioxidants do the following to free radicals: Stopping the cascading of free radical formation, become a radical themselves

a and c

All of the following is true about cooking food except:

all cooking uses the same kind of heat transfer

Boyle's law

as volume decreases, pressure increases

Properties of metals

conductors, loose flow of electrons, heat up and cool down quickly

A saturated solution:

contains all the solute the solvent can handle

In regards to heating food to an edible temperature:

continuously cook food until the desired temperature is reached

Folic Acid

creates the amino acid methionine to help maintain healthy blood vessels witch reduces the chances of stroke or heart disease.

Convection occurs because:

energetic particles collide, transferring energy to the surface of the food

Convection occurs because:

energetic particles collide, transferring energy to the surface of the food The most common example of convection is cooking in your oven. Food in your oven is cooked by energetic molecules circulating around the oven, and coming into contact with your food, transferring the energy. There is no direct contact with the heat source (like on your stove); the energy transferred to the foods through the walls of the oven is a radiant heat; energy transferred within food is heat transfer through conduction.

Water _______________ the boiling syrup solution, __________________ the concentration of sugar and __________________ the boiling point.

evaporates from; increasing; increasing

When boiling:

food is cooked at a constant temperature

Radiation

heat in the form of waves

Radiation Cooking style

heat in the form of waves

Convection

heat is transferred by the movement of currents within a fluid

conduction

heat is transferred through direct contact with the heat source

Induction

heat is transferred through magnetism

Convection Cooking style

heat transfer through fluid

Induction cooking style

heat transfer through magnetism

Interfering agents:

help with the preparation of non-crystalline candies

Browning reactions:

include Maillard reactions develop new flavors occur during the heating of sugar all of the above******

Will the solubility of the solute increase or decrease if sucrose is dissolved in water at 95 °C instead of 20 °C?

increase

Mark all of the true statements about metals below:

metals will heat up and cool down quickly, metals are good conductors, metals have loose electrons that behave as a fluid

All of the following is true about oxidation except:

oxidation produces lone pairs

Maillard reactions:

produce complex flavors due to amino acids in the proteins

Lycopene

reduces DNA damage (ie helps prevent cancer)

How can premature sugar crystallization be avoided?

remove dried spatter from the pan walls with a moist brush

Brown pan

residues from proteins and sugars released from the meat during cooking

What kind of fatty acids are the most stable?

saturated lipids

Cotton candy:

solidifies into threads when exposed to air

When cooking with alcohol: (choose all that apply)

some of the alcohol is left behind, no matter the cooking method, acidity, sweetness, and savoriness are added to the dish, moisture loss can be reduced if alcohol was used as a marinate

What type of cooking material gets "the closest" to being both chemically unreactive and a good conductor?

stainless steel with a copper plate

In candies such as fudge, it is important to:

stir the mixture continuously in order to have finer sugar crystals

Candy ingredients

sugar and water

All of the following is true about the cold water test except:

the higher the concentration of syrup, the softer the ball

Carryover Cooking

the phenomenon in which food continues to cook after it has been removed from the heat source as the heat is distributed more evenly from the outer to the inner portion of the food

What is true about how our bodies metabolize alcohol? Choose all that apply.

the stomach and liver break down alcohol, women are more affected by alcohol than men because they can't break down as much of the alcohol before it passes to the bloodstream, the amount of muscle and body fat a person has affects how their bodies metabolize alcohol

In a solution, the solvent is:

the substance in the greatest amount

In a solution, the solute is:

the substance that is dissolved

Caramelized sugar has all of the following characteristics except:

the sugar is now sweet and odorless

Since yeasts feed on the sugars to convert them into alcohol, what can you assume about the sweetness versus alcohol content in wines?

the sweeter the wine, the lower the alcohol content

The smoke point is:

the temperature at which fats boil.

All of the following is true about heat and temperature except:

the terms can be used interchangeably in cooking

Compounds have different melting and boiling points based on the forces holding the molecules together. Different forces are present that give water and fats vastly different melting and boiling points. What forces hold molecules of fat together?

van der Waals interactions

The specific heat capacity:

varies between materials is the energy needed to heat 1 g of substance 1 K ***all of the above*** explains why melted cheese on pizza can burn your mouth but the crust will not

Juices on Plate

Juices leaking out of the steak after being cooked while the meat "rests"

All of the following are ways to prevent you carbonated beverage from going flat. (Check all that apply.)

Keep it cool / refrigerated, Reduce the volume of air above the solution.

Combinations of substances that aren't held together chemically are called:

Mixtures

Strong bonds.. Weak bonds..

Need heat to change; harder to break Can change at room temperature

Will eicosapentaenoic acid dissolve in water (eicosapentaenoic acid)

No

Vegetable that is main source of starch

Potatoes

When baking: Food is cooked by the air, Food is cooked by the heat from the walls of the oven

Both a and b

When steaming food: water vapor condenses onto food, transferring energy, more conduction occurs within the food than in an oven.

Both a and b

When grilling, what types of heat transfer can occur? Radiant, Convection

Both of the above

Which ions tend to cross-link with pectin to provide firmer vegetables?

Calcium

Carbon steel is a great cooking material because it is both non-reactive and has great conducting power.

False

Cis fatty acids are more stable.

False

Deep frying uses the same type of heat transfer as pan-frying.

False

Even though foods cooked by varying methods have multiple forms of heat transfer, the predominant source of heat is always radiant.

False

Fat soluble minerals are easily leached from vegetables while cooking.

False

Food must be cooked for a certain time, and the temperature of the cooked food doesn't matter.

False

Foods prepared by molecular gastronomy methods should be consumed with caution.

False

Free radicals represent a pair of electrons and are formed from breaking weak bonds.

False

Gelatin and pectin are used to make hard candies.

False

Hydrogenation converts a saturated fat into an unsaturated fat.

False

If the volume of a gas goes down the temperature go up.

False

Induction occurs due to a steady electromagnetic field.

False

Marshmallows use an acid base reaction to produce the bubbles inside of them.

False

Nonmetallic solids are the best conductors.

False

Pressure and Volume are directly related.

False

Pressure cookers work because they lower the pressure, allowing food to cook at a higher temperature.

False

Pressure is area / force

False

Smokers use a direct heat source to cook food.

False

Sodium and potassium metals will give rise firmer vegetables.

False

Supersaturated solutions contain less dissolved solute than they can contain

False

The more often a gas collides with the boundary the lower the resulting pressure.

False

The only fluid that undergoes convection is air.

False

You can get all of the antioxidants you need from consuming just blueberries.

False

Smokers use a direct heat source to cook food.

False- Use indirect

The boiling point of a syrup _______________ with increasing concentration of sugar.

Increases

Mark all of the true statements about metals below:

-metals will heat up and cool down quickly -metals have loose electrons that behave as a fluid -metals are good conductors * Metals are good conductors; good conductors are usually not also good insulators. Metals have electrons that are held loosely, so they behave as a fluid to transfer energy. Good conductors will heat up fast, but will also cool down quickly.

When steaming food:

-water vapor condenses onto food, transferring energy -more conduction occurs within the food than in an oven

Vegetable Cooking Methods

-Baking: Using skin to contain heat; conduction -Boiling: Convection method - Steaming: Takes longer than boiling but holds more of the nutritional value - Pan fry: Cooked with steam from the water of the cut vegetables, best for leafy greens

Versatility of alcohol structure

-One end has a CH3, which resembles oils. This makes it able to mix with fatty substances - The other end has an -OH, making it able to mix with water

Pressure Cookers

-This speeds up cooking times by trapping the steam that escapes from boiling water, increasing the pressure on the liquid, thus increasing the boiling point to around 250 °F - With a higher boiling point of water, this cooks the food faster

Pan-frying:

-allows more flavor development with the addition of oil and browning reactions -requires a balance between cooking the inside of the food enough without burning the outside -allows uniform heat contact when an oil is used *****ALL OF THE ABOVE*****

When baking:

-food is cooked by the air -food is cooked by the heat from the walls of the oven

Mark all of the true statements about metals below:

-metals have loose electrons that behave as a fluid -metals are good conductors -metals will heat up and cool down quickly

Candies are rarely spoiled by the growth of bacteria due to: the high sugar content, the low moisture content.

A and C

Juices on top of steak

After searing one side of the steak, while searing the other side, juice builds up on the surface of the meat.

Sugar bonds

Bond to eachother in orderly arrays and form dense, solid masses, or crystals Form saturated solutions

When Herve This started studying molecular gastronomy, he prepared rules for cooking food, wanted to develop a systematic study of food preparation, partnered with a physicist to launch the new discipline.

All of the about

Antioxidants: are large molecules, are molecules with multiple double bonds, come from a variety of foods

All of the above

Browning reactions: develop new flavors, occur during the heating of sugar, include Maillard reactions

All of the above

Free radicals: Are produced from environmental toxins, are highly reactive, cause damage to DNA

All of the above

Hard candies: have a very high sugar concentration, have corn syrup added to the syrup to prevent premature crystal formation, are non-crystalline candies.

All of the above

Sugar molecules have a tendency to: bond together in orderly arrays, form a dense mass, form crystals.

All of the above

The chewiness in caramels, toffees, and taffies is due to: the higher moisture content, corn syrup, milk casein proteins.

All of the above

The mixture for spherification: Creates a gel between alginate and calcium chloride, creates cross-linked polymers, is mixed with sodium alginate.

All of the above

The specific heat capacity: varies between materials, explains why melted cheese on pizza can burn your mouth but the crust will not, is the energy needed to heat 1g of substance 1 K

All of the above

What causes free radical formation? The sun, cigarette smoke, pollution

All of the above

Yeasts: convert sugars into alcohol, are single celled micoorganisms, produce carbon dioxide when breaking down sugars.

All of the above

Pan-frying: allows more flavor development with the addition of oil and browning reactions, allows uniform heat contact when an oil is used, requires a balance between cooking the inside of the food enough without burning the outside

All of the above.

Supersaturated solutions: contain more dissolved sugar that it normally could at that temperature, will induce crystal sugars with a small disturbance, are formed when a hot sugar solution begins to cool.

All of the above.

Veggie colors

Betalains- red-violet and yellow Clorophyll- Green Carotenoids- yellow, orange, and red fat soluble pigments Anthoaxnthins- Colorless in acid but yellow or white in basic Anthocyanins- Colorful pH indicator Fat soluble vitamins are A, D, E, and K

Why don't candies go bad

Candies have a low moisture content and concentrated sugars

All of the following are good methods of cooking vegetables EXCEPT:

Canning

Sugar syrup that is cooked at a lower temperature, have the most moisture, and are the softest of the non-crystalline candies usually produce:

Caramels

Carbon, hydrogen, and nitrogen are all ______________ that cannot be broken down into other substances.

Elements

Acidic ingredients are sometimes added to candies to balance the texture.

False

Adding additional water to your vegetables will help maintain the nutritional content especially for vitamin B and C.

False

Alcohol has a higher boiling point than water.

False

Alcohols are able to be distilled because they have a higher boiling point than water.

False

Anti-oxidation is the same as oxidation.

False

Antioxidant free radicals are less stable and more reactive than the radical that formed them.

False

Berries are not good sources for antioxidants.

False

Both healthy and unhealthy cells have pairs of electrons.

False

Broccoli is part of the lily family.

False

Brown residue on your pan is a sign that searing in juices of a steak is not all it cracked up to be.

False

Browning reactions occur under 100 F.

False

Browning reactions occur under 100 oF.

False

Browning reactions usually occur when food is boiled.

False

Vitamin A

Regulates the growth of cells and our eyes detect light

Temperature during phase change

Stays constant during phase change until all the substance has been converted

Which method is recommended for cooking vegetables to avoid loosing the vitamins and minerals?

Steaming

Are the individual bonds/interactions that hold water molecules together stronger or weaker than the individual bonds/interactions that hold molecules of fats together?

Stronger

__________ containing compound gives rise to strong flavor / odor vegetables.

Sulfur

Is the bond indicated bond 1 a cis or trans bond?

Trans

Which is more stable: a cis or trans fatty acid?

Trans