Food Science Final Test Questions

When meat proteins are put into a phosphate solution, the proteins will

both of the above- increase net neg charge AND move further away from their ISO point

Which of the following has the narrowest plastic range? -butter -veg short -roll in margarine -palm kernel oil

butter

Homogenization modifies the following components of milk:

fat particle size & protein state (native v. denatured)

All fats and oils are mixtures of

fatty acids

1 out of 1 points The candies are all non-crystalline (amorphous) candies except: -fudge -lollipops -candy canes -caramel -toffee

fudge

Albumins are classified as the following type of protein:

globular

Building blocks of cornstarch is ___________. The starting material for glucose corn syrup is _______________________.

glucose ; cornstarch

When the fresh meat is exposed to air, the meat pigment binds with oxygen, the muscle tissue turns to a bright pink-red color. At this stage, what is the meat pigment called?

oxymyglobin

High acid food is defined as food with ______.

pH 4.6 or lower

Which instrument will I use to measure the pH of lemonade?

pH meter

All the cell wall components remain intact when heated, except ______.

pectin substances -polysaccharides + starches break down to sol form

What is invert sugar?

Fructose and glucose in equal amounts

Which fat is more likely to spontaneously undergo hydrolytic rancidity? -safflower oil -margarine -olive oil peanut oil

margarine b/c of water content

All organic molecules contain which type of bond?

(C)ovalent

Chemical change in food:

*Roasting of coffee beans* possible Answers: Roasting of coffee beans Grinding of peanuts Whipping of eggs All of the above None of the above

A thickened starch mixture that no longer flows is called a:

Gel

What are examples of intramolecular polar covalent bonds?

H20 , CH4

When liquid water is heated to water vapor (gas), _____.

Its intermolecular H-bonds break (NOT the intramolec covalent bonds)

Calculate mg of sodium in one serving of pasta based on the information provided: Assume no water evaporation from the pot. Round to the nearest whole number. Ingredient Amounts: Water 3500 g Salt 45 g Dry pasta 950 g The final weight of the cooked pasta is 2010 g. One serving of pasta is 140 g.

3500 - 45 = 3,455 g water total 3455/3500 = 98.7% water ; 1.3% salt total weight: 4,495 g .013 * 2010= 26.13 g/ FW pasta; 14.36 serv 1.82 g per serving Correct Answer: 375 mg Sodium/serving

How many valence electrons are found in the species Na+?

8

All solid fats are:

A network of liquid oil droplets trapped in solid fat crystals

Retrogradation is

A reforming of hydrogen bonds into crystalline regions as the starch paste is held

Which scale would I use to measure 0.5 grams of oregano?

A scale with a readability of 0.01

The addition of baking soda to the cooking water of a vegetable such as green beans will result in _______.

A soft, bright-green vegetable -BS makes water more alkaline, alkaline causes chlorophyl to maintain it's color; whereas acid will hold the structure of the veg better but will cause chlorphyll to leech into water + take on more olive green hues

The storage form of fat is

A triglyceride made up of a glycerol molecule and three fatty acids

Acid is often added to a starch gel after gelatinization because

Acid breaks down starch into smaller molecules, causing the gel to thin

Which proteins are lean muscle fibers?

Actin & Myosin

What are the two fractions of starch that are inside every starch granule?

Amylose and amylopectin

Colloidal dispersions are stabilized by all the following except

Antioxidants

A preparation method where meat is soaked in a solution that results in the opening up of meat fibers and increasing the water holding capacity of the meat proteins.

Brine

How is it that butter has a lower final melting point than lard, yet lard has less saturated fatty acids?

Butter has shorter saturated fatty acid chains

Which of the following functional groups is hydrophobic? -CH3 -NH2 -SH -OH

CH3

Given everything else held steady, which of the following custards will be completely cooked (coagulated) first:

Caramel custard made with whole milk -more water/ less protein + fat in milk= lower temp to coag than high protein/fat concentrations

Which of the following plant pigments are not water-soluble?

Carotenoids

The two factors that influence the melting point of a fatty acid

Chain length and number of double bonds

Distinguish between climacteric and non-climacteric fruit and also give at least an example for each category

Climateric fruits ripen AFTER harvest, as their cellular respiration continues to increase. This includes fruits such as peaches, pears and bananas. Non-climacteric fruit ripen BEFORE harvest, as they do not have any increased respiration once harvested, instead they just begin to rot. This includes fruits such as grapes and citrus fruits.

Sugar decreases the viscosity of starch gels by

Competing for water, thus decreasing swelling

You've made a blonde-roux béchamel with potato starch that has a Bostwick reading of 4 cm/30 sec. You feel it's too thick, and it has a bland taste; it's lacking in the nutty flavor you were going for. What could you do the next time to make it thinner with an even nuttier flavor?

Cook the roux longer

Which type of bond is creating the sponginess of coagulated egg proteins?

Disulfide bridges in tertiary structure -b/c of polar and non polar pattern, creates space between folds (sponginess)

Starch is mainly located in______ of wheat kernels?

Endosperm

What type of linkage connects the fatty acid to the glycerol backbone?

Ester linkage

An electrostatic attraction between two atomic species or functional groups of opposite charge. One species must be a partially-positive Hydrogen:

Hydrogen Bond

Which is the main source of trans fatty acids in foods?

Hydrogenated fats

Another name for an alcohol group:

Hydroxyl

The justification and purpose of an experiment are usually found in the

Introduction

What type of bond is holding together the atoms in MgCl2?

Ionic

Brownian movement

Is one of the three factors responsible for stabilizing colloidal dispersions.

When making a quick cheese, if you add salt before heating the milk

It will require more acid to coagulate the proteins

Cocoa bean roasting is a process that creates:

Maillard Browning

Where is most pectin found in plant structure?

Middle lamella

Rock candy must

Not contain interfering agents

What is the main monounsaturated fatty acid in milk fat?

Oleic acid

Odor is perceived through:

Olfactory cells

Which type of rancidity creates free radicals?

Oxidative -breaks glyc backbone from chains and free radicals are formed--> release esters which cause rancidity

What is the substrate of the enzyme proteases?

Proteins

Denaturation of proteins by heat occurs as protein molecules _____.

Relax from their tertiary structure and form secondary bonds between molecules

A measure of the amount of solid fat in a fat at any given temperature:

Solid Fat Index

TEST 2

TEST 2

TEST 3

TEST 3

The browning reaction that occurs gradually when sweetened condensed milk is heated is

The Maillard reaction

Which sensory attribute is received via chemo-receptors?

a. Taste b. Aroma c. Feeling factors d. **All three**** e. a and b

What type of force or attraction holds one oil molecule to another without forming a true bond?

Van Der Waals

Caramelization creates flavors:

When glucose and fructose break down into small fragments in the presence of high heat.

When you add ACID (H+) to MILK it becomes less-soluble in water. Why?

You REDUCE the net negative charge

An Ion is:

an atom that has donated or accepted electrons

To maintain high quality, potatoes should be stored

at room temp

Hydrolytic rancidity is promoted by

heat and/or lipase

A high free fatty acid content is an indication of

hydrolytic rancidity

Acid ______________ sucrose, breaking it into its two subunit sugars

hydrolyzes

an attraction b/w ions of opposite charge

ionic bond

C18:0 is an example of which type of fatty acid:

long chain saturated

When acid is added to milk, the whey proteins

remain in the solution

A polar molecule is a molecule that contains polar covalent bonds that:

share electrons between two atoms unequally

Which fat would likely undergo oxidative rancidity the fastest? -Soybean Oil -Coconut Oil -Butter

soy bean oil

____________________ is the major digestible carbohydrate in our diets.

starch

Powdered sugar is a form of:

sucrose

Examples of pure substances

sugar, water, salt, all of above ALL OF ABOVE

Starch slurry is considered as a ______. Starch in a sol is the _______.

suspension dispersed

Lean muscle fibers influence water holding capacity of meat because

they are primarily made of polar amino acids

What is the starting material for fat hydrogenation?

vegetable oil

What are the requirements in order for starch to undergo gelatinization?

water and heat

All molecules that promote the sense of 'taste' must be:

water-soluble

In traditional cheese making, which protein requires heat to precipitate out of solution?

whey protein ~b/c water-sol, only way to leave solution would be evaporation

The most abundant proteins in milk curd are

αs-casein, β-casein, and κ-casein