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Food Chemistry

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Name two fermentation sources of chymosin.
kluyveromyces marxianus variety lactis and e. coli
TWEEN belongs to what groups of food additives?
Emulsifiers
The two polysaccharides that comprise starch are _________ and _______________
amylose and amylopectin
Name 3 ways one could reduce the occurrence of Maillard browning.
decreasing moisture to very low levels, increasing moisture to very high levels, lowering pH or temperature, removing one of the substances (typically sugar)
The two chemical components of a triacylglycerol are what?
glycerol and fatty acids
The wavelength of which color in the visible spectrum is closest to the x-rays?
Violet (Purple not acceptable)
What happens to lipids in deep frying?
Hydrolytic oxidation and color change
What enzyme causes browning in apples?
polyphenol oxidase
What compound in chocolate stimulates the central nervous system and makes dogs sick?
Theobromine
What is the spontaneous loss of fluid from a food gel is called?
syneresis
What is the driving force of osmosis?
chemical potential
What is the food dye carmine made from?
Insects
What is measured on the basis of the dipole moment of a single molecule?
dielectric constant
The oxidation of the iron in myoglobin to the ferric state results in the brown pigment called...
metmyoglobin
What is poising capacity?
apparent resistance to change in redox potential
What is latent heat of fusion?
the constant temperature where a solid turns to a liquid.
An example of a "saturated" fatty acid is the 16 carbon molecule called ____________?
palmitic acid
Name 3 non-nutritive sweeteners approved for use in the USA?
Saccharin, Aspartame, Acesulfame-K, stevia, sucralose, neotame
What is the pH range of the indicator, phenolphthalein?
8-9.6
What 2 antibiotics are legal food additives?
nisin & natamycin
Which of the following is not a major mineral? Ca, Fe, K, S, Na
Sulphur
What are the two types of bloom in chocolate?
sugar bloom and fat bloom
What are the precursors of apocarotenoids?
carotenoids
Glucuronic acid is an example of: fructose metabolite, sugar acid, sugar alcohol, glucose metabolite
Sugar acid
Which compounds found in grapefruit act to inhibit Cytochrome P450 Enzyme and cause potentially dangerous drug interactions?
Furanocoumarins interfere with blood settings so they can be dangerous.
What are the common names for the saturated fatty acids with the following chain length 4, 6, 8,12,16,20 carbons.
Butyric acid, caproic acid (6), caprylic acid, lauric acid, palmitic acid, arachidic acid
An enzyme that catalyzes formation of hydroperoxide from fatty acids is what?
lipoxygenase
What would you do to change a temperature reading from Farenheit to degree Rankine?
add 459.67
What is the bond angle of the H-O-H bond?
105 degrees
Potassium sorbate is primarily used as a food preservative. Why is it used more than its acid form, sorbic acid?
Because the salt is more soluble in foods than the acid.
What does PER stand for?
Protein efficiency ratio
Which tannins can tan? hydrolysable, condensed tannins, phyto, non-condensed
Condensed tannins
The n-acetylmuramidase enzyme found in egg whites that hydrolyzes the cell walls of gram positive bacteria has the common name.
lysozyme
Name 5 antimicrobial spices.
cinnamon, cloves, mustard, allspice, horseradish, onion, garlic, oregano, thyme, cumin, rosemary, ginger, basil, fennel, coriander, black pepper
What are the Standards of Identity for high, medium, and low fat contents in chocolate/cocoa?
High fat (breakfast cocoa) – not less than 22% cocoa fat, Medium fat - less than 22% cocoa fat and not less than 10%, Low fat - less than 10% cocoa fat
There are 3 saturated sugar solutions: fructose, glucose, sucrose. List the order in which sugars would crystallize.
sucrose(doesn't mutarotae), glucose, fructose
Rank the relative sweetness of the following polyhydric alcohols: sorbitol, glycerol, xylitol, mannitol
most sweet: xylitol, glycerol, mannitol, sorbitol
Name the four classes of proteolytic enzymes based on active site.
Serine, metallo, aspartyl, cysteine
Why do chelating agents increase the efficiency of antioxidants?
they bind trace minerals that catalyze fat oxidation
For the following saturated fatty acids, give the systematic name or molecular formula: Palmitic acid, Stearic acid and acetic acid
palmitic: n-hexadecanoic, C16 H32 O2; stearic, acetic acid: Ethanoic acid C2 H4 O2; Stearic acid: Octadecanoic acid, C18 H36 O2
What is a peptide bond?
covalent bond between 2 amino acid molecules.
Why do carrots not lose their orange color during cooking?
carotenoids are heat stable and fat soluble
What is the isoelectric point?
The pH where the sum of charges (+ and -) is equal to zero for an amino acid/protein
What is glucono delta lactone?
GdL (glucono-delta-lactone) is a widely used acidulant in meat products, especially for dry cured sausages. It is used when a slow release of acid is required. In the presence of water it reverts to gluconic acid. The lowering of the pH inhibits growth of bacteria and accelerates the drying
What kind of an emulsion is mayonnaise?
Oil in water
Which general class of tannins contain catechin or epicatechin as its monomeric units?
hydrolyzable tannins, condensed tannins, Non condensed tannins, phytotannins
Shortening is defined as any ______ used in baked products.
fat or oil
In the SI system what are the units that are applied to the following five dimensions or measurements; length, mass, time, electric current, thermodyanamic temperature?
length = meter Mass = kilogram Time = second Electric current = ampere Thermodynamic temp = degree kelvin
What is the desired crystallization type for tempering chocolate?
Type 5
What is the Henderson-Hasselbach equation?
pH = pKa + log [salt]/[acid]
Name two PUFA commonly in foods.
Linoleic, Linolenic
What are the substrates for soy sauce?
soybean, water, salt, wheat
When material naturally absorbs water?
Hygroscopy
What two factors determine the melting range of a lipid?
unsaturation (or saturation) and carbon chain length
What sweeteners are used in Coke Zero?
Asparatame and acesulfame potassium
What is the main class of color compounds found in raspberries?
anthocyanins
Mercene, Limonene, and Pinene all belong to what family of hydrocarbons?
Terpenes
What are the smallest and largest amino acids by MW?
glycine and tryptophan
Pomegranate peel can be used as a natural dye. What color does it produce?
Yellow
Why should olive oil be stored in a dark environment?
prevent photooxidation of PUFAs
This sweetener has about 150-250 times the sweetness power of sucrose and is a dipeptide of aspartic acid and phenylalanine 1-methyl ester
Aspartame
In which year did belgian chemist ernest solvay patented his method for the industrial production of sodium carbonate?
1882
What main compound is responsible for the smell of lavender?
linalool or linalyl acetate
The HLB value is a number from 1 to 18 used to describe effectiveness of what?
emulsifying agents
Polar groups form hydration shells in water by what type of interactions?
dipole-dipole or H-bridges
Which fatty acid would be expected to have the highest iodine value: linoleic, oleic, or linolenic?
linolenic (18:3) more unsaturation
What are the three steps of fat autoxidation?
Initiation, Propagation, termination
Name the fatty acid that contains 18 carbons and three double bonds?
Linolenic acid
Bitter compounds in coffee after roasting?
Chlorogenic acid, phenyl indane
What is the name of compounds that can act as either an acid or a base?
Amphoteric
Cheeses from highest to lowest protein content. Cheddar, swiss, cottage, feta.
Swiss>Cheddar>Feta>Cottage
Caffeine belongs to what class of compounds?
methylxanthine
Name the sulfur containing essential amino acids.
methionine
What are the five types of bonds found in proteins?
Peptide, Ionic, disulfide, Hydrogen, hydrophobic interactions
What is the main water soluble component of coffee?
caffeine
Name 3 factors that affect enzyme catalyzed reactions.
ph, temp, [substrate], [enzyme], ionic strength, activators, inhibitors
The best Vitamin A precursor that occurs in food is called
B-carotene
What is the graph of water activity vs. water content called?
moisture sorption isotherm (MSI)
What is the acid present in fish oil?
Arachidonic acid
Name 5 proteins with good foaming properties.
egg white proteins, the globin part of hemoglobin, bovine serum albumin, gelatin, whey proteins, casein micelles, B-casein, wheat proteins, soy proteins
What is the difference between accuracy and precision
accuracy is how close the experimental value is to the true value, precision is how close experimental values are to themselves
Higher alcohols esterified with fatty acids are called?
Waxes
What are isotonic solutions?
solutions which have the same osmotic pressure at the same temperature
What are sequestrants?
Metal chelator
What are surfactants?
Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.
What is invert sugar?
hydrolysis of sucrose to glucose and fructose
Besides extending shelf life and preventing microbial growth, what is another benefit of reducing the water activity of a food?
a lower water content means a lower product volume, making the product easier and cheaper to transport
Gelato’s texture is due to its density as it is denser than ice cream. How much of gelato is air (%)?
30%, ice cream is 50%
Which vitamins can also be used as antioxidants?
vitamins C and E
Which of the following is a non-reducing sugar? A. Lactose, B. glucose, C. sucrose, D. maltose
C. sucrose
Name 3 factors that influence the rate of lipid oxidation in foods.
fatty acid composition, free fatty acid content versus the corresponding glycerols, oxygen concentration, temperature, surface area, moisture, pro-oxidants, antioxidants
What is a brine of salt, water, and sugar cure?
sweet pickle
True or false: As a result of exposure to heat, most carotenoids undergo isomerization from trans to cis isomers
True
What is the scientific name of the honeybee?
Apis mellifera
In a solution with a pH of 5, what is the charge of chitosan?
positive (pKa at 6.5)
What has more saturated fat: lard, coconut oil or corn oil?
coconut oil then lard then corn oil (when compared to the same weight (not by serving size)
In sucralose, some hydroxyl groups are replaced with which element?
Chlorine
What are the class of food pigments which have similar structure and properties to anthocyanins, but are yellow in color called?
Flavonoids
how many carbon atoms and how many double bonds are in arachidonic acid?
20 carbons and 4 double bonds
What is the fundamental driving electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
What is a chemical leavening system, and what are the two essential components of a chemical leavening system?
A Chemical leavening system is a system of controlled carbon dioxide release to give rise to baked products, the two components are a leavening agent. sodium bicarbonate) and acidic agent
What is the aroma of diacetyl?
Buttery
Name 3 physical agents capable of denaturing proteins.
Heat, cold mechanical treatments, hydrostatic pressure, irradiation, interfaces
If oxygen attacks an unsaturated fatty acid at the double bond what is the resultant product?
aldehydes (2 aldehydes)
What is the subunit of pectin?
D-galacturonic acid
Bromate is added to flour for what purpose?
Oxidizing agent
What is the pungent compound in mustard seed, cabbage and horseradish?
sinigrin
In food irradiation, what does URP stand for?
Unique Radiolytic products
What is the artificial color number of Sunset Yellow?
Yellow No. 6
What is the building block structural component of carotenoids called?
Isoprene or isoprenoid units
Name 3 anti caking agents.
Ca Al silicate, Tri Ca phosphate, Ca silicate, Cellulose, Silicon dioxide, etc.
What is the color of carmine cochneal extract?
Red
What is struvite?
Magnesium ammonium phosphate crystals which look like glass and are sometimes found in canned tuna fish
In directed interesterification, higher melting and least soluble TG molecules in the mixture crystallize. This is achieved by _________________.
lowering the reaction temperature
What enzyme is responsible for the development of garlic aroma upon cutting or cellular damage?
Allinase
What are the major antioxidants found in Rosemary extract?
Rosmarinic acid, carnosol and carnosic acid
The ester of which 2 compounds compose chlorogenic acid?
quinic acid and caffeic acid
Name three functions of enzymes used as food additives.
speed up reaction; lower viscosity; improve extractions; enhance separations; improve their flavor, texture, digestibility, and nutritional value, enhancing product yield, improve preservation
What is the toluene distillation used for?
moisture content determination
Trans fatty acids occur naturally in what type of animal?
Ruminant animals
What are colligative properties?
physical properties of a solution that depend entirely on the number of solute molecules present in a solution and not upon the chemical nature of the solute ie vapor pressure, osmotic pressure, boiling point
What are the 2 main starting products of the Maillard reaction?
reducing sugars, free amino acids
What does the % overrun measure in whipping cream and ice cream?
The amount of incorporated air into the product.
Which chemical bond has functional groups on opposite sides of the chain?
Trans-bond
The bitter glucoside in olives is called ______________
Oleuropein
Give an example of fats/oils classed as Oleic-Linoleic Acid fats.
Peanut, sunflower, safflower, olive, sesame, soybean
What are the three main classes of carrageenan?
Iota, Kappa, Lambda
Give the Henderson Hasselbach equation and define each term.
ph=pKa + log[A/HA] ph = -log[H+] pKa = ionization constant A = concentration of dissociated (-ion) HA = concentration of undissociated ions
Name two components of the SNF portion of milk
lactose, casein, and whey
What happens to the properties of a vegetable oil when it is hydrogenated?
increases the melting point
What happened when there is a white coating on the surface of choclate?
Fat/sugar bloom
The wavelength of which color in the visible spectrum is closest to the x-rays?
Violet (Purple not acceptable)
What happens to French fries that are made from potatoes stored in the refrigerator?
they will brown unevenly due to sugar content
Describe the mechanism by which CaCl2 firms plant tissues.
divalent Ca++ binds the carboxyl groups of adjacent pectin polymers forming bridges and tightening the structure
What is the temperature scale that follows Fahrenheit, but gives you absolute temperature?
Rankin
What is the acid in onions that results in tears when the onion is cut?
sulfenic acid
Cleavage of K-casein gives
para kappa casein, glycomacropeptide
Why is baking soda used in making pretzels?
Raises the pH, hence allows browning to occur more readily
The main lipid class in lean or low fat fish is ____________?
Phospholipids
What salt causes coagulation in tofu?
Ca sulphate or MgCl2
What is the difference between a "dextrin" and a "dextran"?
Both are intermediate length carbohydrate chains composed of glucose units. Dextrins are formed by acid or enzymatic hydrolysis of starch; dextrans are synthesized by microorganisms
What are the harmful compounds formed during hydrogenation of fatty acids
trans fatty acids
What is the definition of pH?
PH stands for Hydrogen potentials. It refers to the concentration of the hydrogen ions in a solution in logarithmic scale
Name 6 fatty acids in chocolate.
Capric, caprylic, lauric, myristic, palmitic, oleic
Which lipoprotein transports triglycerides from the liver to adipose tissue?
VLDL
The dispersion of one liquid in another immiscible liquid is called what?
Emulsion
What is the definition of a gel?
a liquid dispersed in a solid.
Name 2 reasons why pectin is used in the processing of fruit juice.
To increase clarity and yield
In kJ per mol, what is the bond dissociation energy of the O-H bond in a water molecule?
25
Why is "Japanese" or "short grain" rice more sticky than "indian" or "long grain" rice after cooking?
waxy variety (high amylopectin). Long grain rice has more amylose, and gives off less starch than short grain, high amylopectin rice.
What are the main classes of flavonoids?
Neoflavonoids, isoflavonoids, bioflavonoids
Regular orange extract contains 250 flavor compounds. How many are found in artificial orange?
6
What are the 2 classes of food colorants?
certified and noncertified
What are the two types of certified food colorants?
lakes (water and oil soluble) and dyes (water soluble)
What is the coordination number of stable ice-I?
4
A substance that reduces molecular damage due to Oxygen, such as free radical damage to cellular tissue is called what?
Antioxidant
Name two types of rancidity.
Hydrolytic and oxidative
What is the term that describes polymeric crosslinking that entraps the solvents between junction zones?
Gelation
Name an enzyme involved in fruit softening.
pectin esterase, polygalacturonase, pectin layase
What is the latent heat of fusion?
temperature remains constant as solid turns to liquid
The artificial sweetener which is also a dipeptide?
Aspartame
Arrange them according to saturated fat percentage: butter, coconut, pork fat, olive oil
coconut (90), Butter (63), pork fat (37.5), olive oil (14)
Furfural mercaptan is a volatile largely found in what food?
Fresh roasted coffee
How many percentage of sugar is in semi-bitter chocolate? a. 15%, b. 30%, c. 45%, d. 70%
b. 30%
Why does water have a high dielectric constant?
large network of water molecules extending over several H-bonds, water molecules associate through H-bridges and proton transport takes place along H-bridges
What is an emulsion?
a system containing 2 immiscible liquids
How does high moisture content of foods affect browning?
causes browning to happen more slowly
The safety of seafood is influenced by the presence of the biologically active amine, histamine. How is it formed?
it is formed in spoiling fish by decarboxylation of the amino acid histidine
What is the percent of non-fat solids found in whole milk?
8.25
In maillard browning, reducing sugar reacts with which amino acid and destroys its nutritional value
Lysine
What compound is formed when glycerol is heated?
acrolein
What is the most abundant unit that makes up the structure of pectin?
galacturonic acid
Which fruit can be added without destroying the gel: pineapple, papaya, kiwi, strawberry, fig
Strawberry (no proteolytic enzyme)
What milk protein is a cofactor for the synthesis of lactose?
alpha lactalbumin
What is activation energy?
energy required to start a chemical/enzymatic reaction
What are the toxic glycosides present in lima beans and cassava?
cyanogenic glycosides
What term describes the ability of fat to exist in different crystalline forms?
Polymorphism
What color of anthocyanin pigment predominates at an acidic pH?
Red
Anions form hydration shells in water by what type of interaction?
ion-dipole
Name 3 specific enzymes that act on pectic substances.
pectin methylesterase, polygalacturonase, pectin lyase
What is the major color compound in tomatoes?
Lycopenes
What are two fats/oils in the class known as Lauric Acid fats because it has high content of Lauric Acid (Dodecanoic 12:0).
Coconut oil and palm kernel oil
Name two compounds that result in mushroom aroma.
2-octanol, 1-octan-3-one
What class of chemical compounds are responsible for the brilliant red color in paprika?
Carotenoids
Which is the Sweetner developed by Cargill?
Eversweet
List 3 in vitro assays for determing alternative oxidase(AOX) activity.
ORAC, FRAP, DPPH radical, TEAC, CUPRAC, B-carotene-linolenic acid, PCL, TRAP, PSC
What are the uncontrolled fat crystallizations which give chocolate an impaired texture and a grey surface called?
Fat bloom
The carboxy end of the fatty acid is called the _____ position.
alpha
What causes the haze defect in iced tea?
Polyphenols tend to interact with proteins, caffeine, and metal cations to form colloidal suspensions of haze and ‘tea cream’, which are detrimental to product appearance and taste.4 While haze formation can affect color and impair aesthetic appeal, it can also diminish both the shelf-life and the health-promoting properties of the tea.
What causes the pH to drop during the aging of eggs?
loss of carbon dioxide through the egg shell
Rank the following fatty acids from lowest to highest melting point: oleic, elaidic, lauric, linolenic.
linolenic, oleic, lauric, elaidic
Enzymes that catalyze transphosphorylation are called:
Kinases
What is the most commonly used proteolytic enzyme, an extract from the papaya plant?
Papain
What is the alkaloid in irish potatoes?
solanine
Name the strongest biochemical bond and the weakest biochemical bond.
strongest=covalent, weakest=hydrophobic
What is Allose?
D-Allose is a rare monosaccharide, which rarely appears in the natural environment. D-Allose has an 80% sweetness relative to table sugar but is ultra-low calorie and non-toxic and is thus an ideal candidate to take the place of table sugar in food products.
What color are anthocyanins at acidic pH?
Acidic = red
What is the active ingredient in sichuan pepper that induces a tingling sensation?
Hydroxyl-alpha-sanshool
What is petroleum ether?
Mixture of low molecular weight hydrocarbons
What is the strongest biochemical bond?
Covalent
What is the cheapest thickener in the U.S. and what is the most expensive?
Cheapest - unmodified corn starch ($0.18/gk) expensive - agar ($26-31/kg)
What is pH?
the negative log of the concentration of hydrogen ions in a solution.
Give three classes of enzymes relevant to foods.
Oxidoreductases; Hydrolases; Lyases; Isomerases
What mineral is best known as an antioxidant?
Selenium
The animal fat which is characterized by containing appreciable amounts of shorter chain fatty acids (C4 – C12) is
Milk fat
What happens to the melting point of a lipid/oil when its overall level of saturation is increased?
melting point increases
What amino acids comprise aspartame?
Phenyl alanine and aspartic acid.
Name the four categories the plant pigments are classified in.
Carotenoids, anthocyanins, Betalains, chlorophylls
What is the difference between single and double acting baking powder?
Single has 1 acid whereas double has 2 acids; single acting reacts once it is exposed to moisture, double acting reacts when it is exposed to moisture and reacts again when it is exposed to heat
What is the common name for potassium bitartrate and how was it originally sourced?
Cream of tartare, byproduct of wine making
How does ultraviolet light effect fat oxidation?
it speeds it up.
What is the isoelectric point?
the pH where the sum of the charges (+ and -) is equal to zero for an amino acid/protein
How is cocoa butter different from other types of fats?
It doesn’t go rancid and therefore has a long shelf/storage life.
EDTA and citric acid are examples of what group of additives used in foods?
metal chelators - prevent oxidation
What is the name of a 18 carbon unsaturated fatty acid with the double bond at the 12-13 position?
Oleic acid
What is "double acting" baking powder?
The first acid reacts by creating gases when mixed with the liquid in the recipe. The second type reacts by creating gases when the batter is exposed to oven heat.
Percentage of chocolate in milk, sweet, bittersweet chocolate?
Sweet 3, Milk 10, bittersweet 35
What is Capsaicin and where is it found?
Pungent flavor of hot peppers
What is oleostearin?
the solid portion of beef fat after removal of oleo oil
An emulsified with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in water
Lactose is composed of
glucose and galactose
What are the dispersed and continuous phases of each of the following: Foam, aerosol, emulsion?
Dispersed: gas, liquid or solid, liquid;Continuous:liquid or solid, gas, liquid
What is the characteristic fruit flavor compound of cherry?
benzaldehyde
How does altitude affect boiling point?
the air pressure decreases so the boiling point lowers.
List the 6 major classes of enzymes
oxidoreductases, transferase, ligase, lyase, isomerase, hydrolase
What is the Henderson-Hasselbalch equation?
The equation to estimate the pH of a buffer solution containing given concentrations of an acid and its conjugate base
What are the two general types of adulteration of foods?
economic adulteration; addition of foreign material
What sweeteners are used in Coca Cola zero sugar?
Aspartame and acesulfame K
What is the name of the degradation compound of chlorophyll?
Pheophytin
What is the geometric configuration of double bonds in most natural fatty acids?
Cis
What are the hydrogenation products of the following sugars: glucose, fructose, galactose, xylose?
sorbitol, mannitol, galactitol, xylitol
What does AOAC stand for?
Association of Official Agricultural Chemists
Primary product of fat oxidation?
Acetyl CoA
An element found in proteins but not in carbohydrates is what?
Nitrogen
What is the scale for water activity?
0 – 1.0
When two particles merge and don't retain their properties
coalescence
HLB values for oil in water emulsion.
High value (8 to 16)
Polymorphic forms of lipids in chocolate?
5
What is the enzyme responsible for browning in lettuce?
Polyphenol oxidase
What are the major pigments in yellow peppers?
Carotenoids
What compound is responsible for the distinct flavor of horseradish?
Sinigrin
Which of the following oils would become rancid fastest? Canola, soybean, or olive
Canola
Name the microbial gum used in salad dressings.
Xanthan gum
waxes are composed of what two basic chemical entities?
fatty acid (ester linked) to fatty alcohol
What British dessert shares name with atomic model?
Plum pudding
What is the chemical nomenclature for caffeine?
1,3,7-trimethylxanthine
What is the eutectic point?
the lowest point on the freezing point depression curve
The step in which fatty acids of higher melting point are separated by cooling during edible oil manufacturer is called?
winterization
Define and differentiate between the terms “thermoset” (thermally reversible) and “thermoplastic” (thermally irreversible) with regard to protein gel formation and give an example of each.
Thermoset gels form irreversible cross-links and cannot revert back to initial state like muscle proteins(myosin), egg white proteins (ovalbumin). Thermoplastic gels form gels on cooling after heating, and can revert fully or partially back to solution upon reheating like collagen (gelatin)
S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds in what foodstuff?
onions or leeks
Inulin is a polysaccharide found in some plants. What is the monosaccharide that makes up this polymer?
Fructose
Name 5 ways to lower the water activity of a food.
Dehydrate, add sugar, add salt, freeze, drying, combination of any of these methods
If the temperature of a solution is -40 F, what will it temperature be in degrees Celsius?
-40 deg C (-40 is the equivalence point for the 2 temp scales)
What is the molar concentration of disassociated H+ in pure water at 25°C?
1 x 10^7
Why store olive oil in dark?
to prevent from photooxidation
How many amino acids are found in one turn of an alpha helix in DNA?
3.6
What two common compounds are used together as an antioxidative systems in foods?
ascorbic acid and citric acid
The acidulant responsible for the "flat" sourness in cola drinks is what?
phosphoric acid
Name the significance of importance of the following enzymes. Rennet, papain, lactase, alkaline phosphatase
rennet – curdle milk, papain – tenderize meat, lactase – converts lactose to monosaccharides, alkaline phosphatase – indicates milk pasteurization
What is the initiation step in crystal formation?
Nucleation
At what pH can a food be called an acid food?
a pH less than 4.6
Why should you store olive oil in a dark environment?
light oxidation
What is common chemical intermediate in fat, protein, and carbohydrate metabolism?
Acetyl CoA
What happens to a catalyst in a reaction?
Concentration remains same (ideally)
A saturated fat has how many double bonds?
None
What are surfactants?
organic molecules that exhibit both hydrophilic and hydrophobic properties due to the presence of poplar and nonpolar groups.
Fresh lime juice to protein solubility.
increase or decrease solubility
The Fehlings test uses CuO, which reacts with aldehydes. In glucose presence, what is the color of the precipitate formed?
Red
What isomer is less expensive than Vitamin C?
Erythorbic acid
What type of structure is whipped cream?
Foam
Define absolute zero and provide the kelvin, Celsius, and Fahrenheit temperatures for this point.
temperature at which particle motion stops (is minimal), 0 kelvin, -273.15 Celsius, -459.67 Fahrenheit.
What is the most widely grown red wine grape variety in the world?
Grenache
Withering, rolling, fermenting and firing are all processes associated with the production of which beverage?
Tea
Name 8 essential amino acids.
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine (HIL PVT LMT)
Classify these candies as crystalline or non-crystalline: caramel, toffee, rock candy
Crystalline: Rock candy Non-crystalline: Caramel, toffee
The HLB value is a number from 1 to 18 used to describe the solubility of effectiveness of what?
An emulsifying agent
SAP is used as a buffer, leavening agent, and emulsifier. What is SAP?
sodium acid pyrophosphate
What are the 2 most common statistical measures of dispersion for a sampled population?
Variance & standard deviation
Classify each emulsion types: margarine, mayonnaise, milk
Margarine: water in oil; mayonnaise and milk: oil in water
What are the compounds responsible for pungency in the black pepper, chilli peppers, mustard and ginger?
black pepper – piperine, chili pepper – capsaicin, ginger – gingerol, mustard allyl isothiocyanate
Mouthfeel of fat is most influenced by
solid fat content
Name the four types of chemical bonding that occur during bread dough mixing and kneading.
disulfide interchange, hydrogen bonding, hydrophobic interactions, and ionic interactions
Hydrolytic rancidity is caused by what enzyme?
Lipase
What does HLB stand for?
Hydrophilic-lipophilic balance
What protein structure is formed by linear proteins folding into complex?
tertiary
Chlorophyll would be an initiator of what type of oxidation pathway? Enzymatic, photosynthesized, autoxidation, hydrolytic
Photosynthesized
In cooking what is the function of arrowroot powder?
It is a thickening agent
What is Pasteur effect?
the rate of glycolysis under anaerobic conditions is higher than the rate under aerobic conditions. Aerobic: citric acid cycle follows glycolysis; anaerobic: fermentation occurs
What is syneresis?
the contraction of a gel when the liquid separates out.
How many times more acidic is something with a pH of 2 than a substance with a pH of 5?
1000x more
What three amino acids correspond to I, F, T?
Isoleucine, phenylalanine, threonine
Enzyme pills available over the counter can be added to milk to predigest lactose to glucose and galactose. The name of the enzyme is ....
Lactase (b-galactosidase) or Lactase
Name 3 practiced chemical modifications of maize starch in the US.
derivitization (monostarch substitution and cross linking), acid thinning, dextrinization, oxidation, hydrolysis
A high molecular weight polyester deposited in the waxy cuticle of some plant epidermal cells is called what?
cutin
What is the color pigment in turmeric?
Brilliant yellow
When the coordination number decreases during the transition from water to ice, what happens to the density?
density decreases
An enzyme the removes methanol from pectin is called what?
Pectin methylesterase
Name the acids that are present in the following: oranges, grapes, apples, and yogurt
orange: citric, grapes: tartaric, apples: malic, yogurt: lactic
In a water molecule, what are the H-bond acceptor sites?
unshared oxygen electrons
What is the common name for 9,12,cis-cis-octadienoic acid?
Linoleic acid
What is the pigment that is responsible for the green color in cooked broccoli?
Pheophytin
What graphs the relationship betwee water content and water activity?
sorption isotherm
What are enantiomers?
compounds that have the same molecular formula but different structures. They are mirror images of each other and refract light differently
What is the major nutraceutical compound found in red wine and grape skins?
reservatrol
Rank these sweeteners from highest to lowest sweetening power. Sucrose maltose, aspartame, sucralose, stevioside.
Sucralose, Stevioside, Aspartame, Sucrose, Maltose
In milk, what does lactose react with to cause maillard browning?
Lactose reacts with the free amino acid side chain of milk protein (Mainly e-amino group of lysine residue)
What is piperine and where is it found?
An alkaloid that is responsible for the strong peppery kick in black and white pepper
How does rennin act to destabilize the casein micelle?
it divides k-casein into para-k-casein and glycomacropeptide
Name the compound responsible for pungency in mustard, horse radish, wasabi, radish.
Alloisothiocynate
Which food additive did Morton Salt add to their product that allows them to say "When it rains, it pours"?
calcium silicate
What chemical compound is responsible for the fishy smell?
Trimethylamine
What chemical compound is determined as an indicator of maillard browning?
hydroxymethylfurfural
Peptide bond formation results in the formation of what secondary compound?
Water
Name 5 chelating agents used in food.
EDTA, vitamin C, lactic acid, citric acid, acetic acid, malic acid, oxalic acid, pyrophosphate, proteins
What is a component of garlic that has antioxidant properties?
allicin
What is a strecker degradation?
part of a browning reaction, where an amino acid and a dicarbonyl produce CO2 and flavorful aldehydes
TF high density polyethylene is made up of carbon chains that are highly branched.
False
Waxes are composed of what 2 basic chemical entities?
Fatty acid and fatty alcohol
In a water molcule, what are the H-bond acceptor sites?
H-O bonds
What does the process of blanching do?
used to inactivate enzymes and set color
Identify the organic acids in the following products: grapefruit, oranges, grapes, vinegar
citric, citric, tartaric, acetic
What is the equation for the Ideal gas Law?
PV = nRT
What is the major whey protein in milk?
beta lactoglobulin (about 65%)
What is the scale to measure percent sugar?
Brix
What is the term for when electrons occupy free orbitals of cations in a salt/water solution?
aqua complex
Tonka beans have a high concentration of which dangerous compound?
coumarin
Relative sweetness of sugars (low to high): galactose, maltose, glucose, trehalose, sucrose, lactose, mannitol, sorbitol, xylitol, sucrose, fructose
lactose, galactose, maltose = trehalose, mannitol=sorbitol, glucose, xylitol = sucrose, fructose
Name the two synthetic antioxidants and two natural antioxidants.
synthetic: BHA, BHT, PG, TBHQ; natural:alpha-tocopherol, ascorbic acid, ferulic? Acid, sesamol
How many molecules are in a mole?
6.022 x 10^23
At what pH can a food be called a low acid food?
a pH greater than 4.6
Why are linoleic, linolenic and arachidonic acid considered essential fatty acids?
they are n-6 and n-3 fatty acids that cannot be synthesized in vivo
Name four molecular characteristics of proteins desirable for film and foam formation.
soluble; large; amphipathic; flexible domains; interactive regions; disposition of charged groups; retention of structure; and polar residues
Lecithins are structurally like fats but contain what?
Phosphoric acid
Name 2 carotenoid pigments.
beta carotene, xanthophylls
What happens to both the coordination number and distance between nearest neighbor molecules during the transtion from ice to water?
both increase
What are three applications of lactase?
hydrolyzes lactose to glucose and galactose, prevent sandiness in ice cream, lactose intolerance
If 2 M NaOH solution contains 80 g of NaOH, how much NaOH does a 1 M solution contain?
40 g
Which fatty acid has the longest hydrocarbon chain?
Hexadecanoic acid, tetracosinoic acid, octadecanoic acid, Triacontanoic acid (30C)
What is the function of erythromycin?
Antibiotics
What is the difference between a nanoparticle and a colloid?
Size, nano particles are smaller than colloids. Nanoparticles are 1-100nm, colloids range from a nanometer to micrometers.
Another name for triacylglycerol is?
Triglycerides
What color is phenolphthalein under acidic conditions?
colorless
Name 2 natural surfactants.
lecithin, whey protein
For water, the effect of increasing coordination number is most noticeable at what temperature range?
0-4 degrees celsius
What causes the yellow – green pigment of skim milk and whey?
Riboflavin (vitamin B2)
What is the main pigment found in beets?
Betalain
Give two amino acids which contain two ammonium and related groups.
arginine, lysine, asparagine, glutamine
What is gingerol and where is it found?
Characteristic ginger flavor from the ginger root
True or False: Yeast contains glutamic acid.
True, 8-10% of whole yeast
What is the molarity of pure HCL in a pH 7 solution?
10-7 molar
The endosperm of wheat consists of starch granules embedded in a what?
protein matrix
What does MSG stand for?
monosodium glutamate
What is the flavor that is created from the two chemicals of S – (1- propenyl) – L – cysteine sulfoxide and thiopropanol – S oxide ?
Onions
How many times higher is the mobility of proton in ice over water?
100
Categorize each product as suspensions, foam, or an emulsion; cream, fondant, bread, beer, Italian dressing, crab bisque, milk
Suspension – bisque, fondant Foam – beer, bread Emulsion – Italian dressing, milk
What is the name of the alternate liquid crystalline forms of the same fat?
Mesomorphs
Name one of the three amino acids that can not be cleaved by carboxylpeptidase A at the free carboxyl end.
lysine, arginine, proline
Which of the following oils can be used as a lubricant?
rapeseed oil
Define the primary, secondary, tertiary and quaternary structures of proteins?
Primary=amino acid sequence, secondary=alpha-helix, beta sheet. Tertiary=one complete protein chain with cross bonds linking it together. Quaternary= four separate protein chains assembled as one.
Name the type of rancidity, which occurs by the hydrolysis of an ester bond and produces free fatty acids.
Hydrolytic rancidity
What amino acids, with an aromatic side chain, have hydrophilic properties?
Tyrosine
What ingredient makes tonic water fluoresce?
quinine
Name the two primary fatty acids within coffee beans.
linoleic and palmitic acid
What are the three kinds of water in food?
Free water, loosely bound water, water of hydration
Categorize the following pigments in water or fat soluble and plant or animal source based: Carotenoid, myoglobin, anthocyanin, chlorophyll, melanin
Carotenoid: Fat, plant Myoglobin: Water, Animal Anthocyanin: water, Plant Chlorophyll: Fat, Plant Melanin: Water, plant & animal
Rank in increasing water activity: Honey, bread, condensed milk, peanut butter
Peanut butter, honey, condensed milk, bread
Please define water activity.
the ratio between the vapor pressure of the food itself and the vapor pressure of distilled water under identical conditions.
Give an example of a component of unsaponifiable matter
Sterols, cholesterol
What class of pigments has 2 cyclic aromatic rings, one with oxygen included?
flavonoids
What is another name for dihydrogen monoxide?
Water, H2O
What chemical name of the water-soluble pigment of the cochineal insect?
carmine or carminic acid
Eugenol is the active and pungent component of what spice?
Cloves
Definition of pH ?
-log[H+]
The preserving activity of vinegar has been known from ancient time. The active component is
Acetic Acid
What are the four primary classes of plant pigments and give a food example for each class?
Anthocynain – grapes, berries, Caratonids – carrots, tomatoes, Chlorophyll – anything green, beta lymphs – beets
The molecular structure that makes emulsifying agents effective is _____?
lipophilic (hydrophobic) part and hydrophilic part
What color are anthocyanins at acidic pH and basic pH?
acidic=red, basic=blue or yellow
What is the main components causing browning in bananas?
enzyme (ppo) and phenols
Name 5 spices that contain the flavor compound eugenol.
Cloves, cinnamon, Jamaica allspice, sage, sweet basil, bay leaves, sweet marjoram
What are covalent chemical bonds linking two consecutive amino acid monomers along a protein chain called?
peptide bonds
What is another name for phosphatidylcholine?
1,2-diacyl-:ussn:ueglycero-3-phosphocholine, Fosfatidilcolina, Lipodissolve, Lipolight, Lipolyse, Lipothérapie, Lipotherapy, Phosphatidyl Choline, Phospholipid, Phospholipide, Phospholipon, Polyenylphosphatidylcholine, Polyénylphosphatidylcholine, PtdCho.
Name 5 artificial sweeteners approved for use in the US.
Saccharin Apartame Acesulfame potassium (Ace-K) Sucralose Neotame Advantame Steviol glycosides Luo Han Guo fruit extracts
What is the name of the sweetener that does not participate in maillard browing?
xylitol
What are the described flavors of the following 6 compounds? Diacetyl, acetic acid, acetaldehyde, ethyl hexanoate, propionic acid, 1-octen-3-ol
Diacetyl – butter, acetic acid, vinegar, acetaldehyde – nutty or apple, ethyl hexanoate – fruity, 1-octen-3-ol – mushroom
What is the sweetest occurring substance known to man?
guanidine (discovered in 2016) however thaumatin is also acceptable as this is what is in the Guinness book of world records.
What are the usual components of baking powder?
A carbonate (usually sodium bicarbonate) and an acid.
Milk: Micelles contain protein and 6 – 8% of this salt.
Calcium phosphate
What protein structure refers to the spatial arrangement obtained when a linear protein chain with a secondary structure folds further into a compact three dimensional form?
Tertiary structure
With regard to chemical structure, what do seed gums (locust bean, guar, arabic, mesquite) all have in common?
They are galactomannans
Classify the following baking powders as fast or slow acting:
Tartrates: F; Na Al Phosphate: S; Na acid pyrophosphate: S;
Give the 3 main polymorphic forms of crystalline fat and their general characteristics.
alpha - lowest melting point, least dense, used in foams, lowest stability. Beta prime- median melting point, median density, smooth textures, creaming properties beta - highest melting point high density, highest stability
What pigment produces white color in vegetables?
Anthoxanthin
EPA and DHA number of unsaturation and carbon number and name.
EPA: Ecosapentanoic acid, C20H30O2, DHA: Docosahexanoic acid, C22H32O2, Both are w3
Name a commonly available food source of the isoflavones genistein and daidzein.
Soybeans
What is the isoelectric point of casein?
4.6
What are the minimum reactant requirements for Maillard browning?
amino-bearing compound (usually a protein) and a reducing sugar water
At what temperature does water have its maximum density?
3.92 or 4°C
The reaction of secondary amine with nitrous acid results in the formation of powerful carcinogens called
nitrosamines
In chemistry, what is a mixture of of two liquids with the same constant boiling point and composition throughout distillation called?
azeotrope
What happens to a catalyst in a chemical reaction?
a catalyst can increase the rate of a reaction but the catalyst itself remains unchanged
Name two diamines responsible for the odor in meats (spoiled)?
cadaverine, putrescine
Water soluble pigments occurring in fruits and vegetables whose hue depends on pH are called?
anthocyanins
Name 5 common chemical food additives for food preservation.
BHA, BHT, TBHQ, benzoates, calcium propionate (inhibits molds), sodium bisulfate, sodium nitrate, sodium nitrite
In horseradish what compound is responsible for the spicy or irritating flavor?
Allyl isothiocyanate (breakdown product of singirin)
What compound in black pepper stimulates a heat sensation?
piperine
When the double bonds of carotenoids change from trans to cis forms, what happens to the carotenoid color?
trans is orange/red and cis is lemon yellow
What is the difference between a foam and an aerosol dispersion system?
foam – inner phase is gaseous, outer phase is liquid Aerosol – inner phase is liquid or solid, outer phase is gaseous.
What is the enzyme responsible for browning apples and lettuce?
Polyphenol oxidase
Difference between gelato and ice cream.
Gelato is the Italian word for ice cream. It starts out with a similar custard base as ice cream, but has a higher proportion of milk and a lower proportion of cream and eggs (or no eggs at all). It is churned at a much slower rate, incorporating less air and leaving the gelato denser than ice cream.
Name 4 colorants that are exempt from FDA certification.
Annato extract, zinc oxide, caramel, paprika, riboflavin, titatnium dioxide, turmeric, carmine
The mash obtained in the fermentation of soy to produce soy sauce is called
miso
Name the principal organic acid in apples?
Malic
At what pH does phenolphthalein change color?
pH 8.5
What is the compound in red food coloring that is extracted from insects?
carmine
What effect does ascorbate have on curing with sodium nitrite?
Faster curing action by reducing nitrate to nitrite
The first digit of an enzyme's EC number assigned by the international union of biochemistry identifies ________________.
General reaction type that they catalyze.
You have 1 gram of each of the following sweeteners. Please list them from most sweet to less sweet. lactose, glucose, aspartame, sucralose, sucrose, saccharin
Sucralose, saccharin, aspartame, sucrose, glucose, lactose
Why do bubbles form in boiling but not during evaporation?
in evaporation bubbles do not form because the vapor pressure is less than the atmospheric pressure. Bubbles form in boiling because the vapor pressure overcomes atmospheric pressure
What is the act of debasing food using food additives?
Adulteration
What is aspartame made of?
aspartic acid and phenylalanine (acceptable to add “and methanol”)
What graph tracks the course of the drying process of a food, relative to water content and water activity?
desorption isotherm
Put these nuts in order from least fat content to greatest based on a 1 ounce serving. Pine nuts, cashews, macadamia, chestnuts, almonds
Chestnuts, cashews, almonds, pine nuts, macadamia
What are the additive primaries?
Red, green, and blue light
How many carbons are in lactose?
12
Name five polar amino acids.
serine, threonine, cysteine tyrosine, asparagine and glutamine.
For each of the following fatty acids, give an example of a food oil that contains high levels of each fatty acid. Lauric acid, oleic acid, linoleic acid, linolenic acid and erucic acid.
lauric acid – coconut, pal, kernel Oleic acid – ground nut, rapeseed Linoleic acid – sunflower, safflower, soybean, cottonseed, maize Linolenic acid – linseed Erucic acid – rapeseed, mustard seed
What carotenoid when bound to specific protein is responsible for lobster's distinct pink orange color after cooking?
Astaxanthin
Hydrolysis of glycerol molecules from the TAG is called?
saponification
In kJ per mol, what is the dissociation energy of the H3O+ ion?
100
T/F Chocolate prevents dental caries.
True
Goat stench or goaty flavor is due to which fatty acids (give name and number of carbons)?
Caproic (hexanoic 6:0); Caprylic (octanoic 8:0); capric (Decanoic 10:0)
What is responsible for warmed-over flavor?
fat oxidation
What AA comprises aspartame?
Aspartic acid and phenylalanine
What part of the banana is used to make banana oil?
no part - Banana oil is a synthetic compound made with amyl alcohol
What are the three steps of free radical auto oxidation?
initiation propagation and termination.
This spice consists of the stigmas of a crocus native to the eastern Mediterranean
Saffron
True or false: An oil in water emulsion is best achieved with an emulsifier having a low HLB value.
False. those are for w/o emulsions
Carotenoids are formed from multiple units of what five carbon compound?
isoprene
The chlorophyll reaction in food processing whereby the magnesium is lost by replacement with hydrogen results in the formation of what pigment and what is the color?
Pheophytin – dull olive – brown
Thiobarbituric acid number or value indicates what?
Thiobarbituric acid– lipid oxidation
Azo compounds such as Red No.40 contain this bond.
N=N (Nitrogen double bond)
What purpose Na pyrophosphate serve in foods?
alkaline cleaners
How many valence electrons does oxygen have, and what orbitals are they hybridized to?
6, 4 sp3 orbitals
What does IMF stand for and what is the range of water activity?
intermediate moisture foods, 0.6-0.9 water activity
What is the flavor/antimicrobial compound associated with Thyme?
Thymol
What is the major antioxidant in rosemary extract?
Diterpenes - carnosic acid
The organism that causes 'flat sours' in canned tomatoes is
bacillus stearothermophilus
The acetic acid in vinegar is derived from the bacteria oxidation of what substance?
Ethanol
Name the organic acids found in grapefruit, orange, grape, vinegar.
Grapefruit: citric, orange: citric, grape: tartaric, vinegar: acetic
What are 5 fatty acids found in vegetable oil?
stearic, linoleic, oleic, palmitic, and __________
How many hydrogen atoms benzene has?
6
Name three synthetic antioxidants commonly used in foodstuff.
BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), TBHQ (dl – t – butylhydroquinone)
Falling number measures the activity of which enzyme in cereals?
amylase
What proteolytic enzymes are located in lysosomes?
cathepsins
When does the maximum buffering capacity occur in a food product?
at the pKa, the point where equal amounts of the undissociated acid and weak base (salt) exist in the food matrix
In what two ways can a xanthan gum stabilize an emulsion?
Reduce surface activity, increase viscosity
What are two equations for water activity?
P/Po ( partial vapor pressure of food moisture at T divided by saturation vapor pressure of water at T) and ERH/100 (equilibrium relative humidity at T divided by 100)
What is the approximate number of flavorists in the world?
500
What is the irreversible first product produced during Maillard Browning?
Amadori rearrangement product
What is the major protein in milk?
Casein
What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectin
What is the main acid in lemon juice?
Citric acid
1-aminocyclopropane-1-carboxylic acid is the precursor of what plant hormone?
ethylene
What is the term associated with the oxidation of unsaturated oils?
Rancidity
What preservative is added to wine?
sulfites
List 5 types of bonds that important for the structure of proteins.
covalent, hydrogen, van der waals, disulfide, electrostatic
What are PCB and BCB?
polychlorobiphenyls, and dichloro-biphenyl
What is the name for the Maillard reaction intermediate containing an C=N bond between a sugar and an amine?
Schiff Base or glycosylamine
The molecular structure which makes emulsifying agents effective is _____
contain both a lipophilic part and a hydrophilic part
What is "unsaponifiable matter"?
Fat soluble matter remaining after saponification
Anthocyanins belong to what general class of chemical compounds (or structures)?
Flavonoids
What do we call the prolamines in corn?
zein
What are the 3 forms of water in food?
free water, adsorbed water (loosely bound), and water of hydration (tightly bound)
Name 5 hydrophobic surfactants.
DATEM Soy lecithin Calcium stearoyl lactylate Glycerol monoleate Sorbitan trioleate Oleic acid
What is the common name for a 10 carbon saturated fatty acid?
Capric
Give 3 factors that determine the stability of emulsions.
particle size, pH of phases, type of emulsifier, size of globules, viscosity, interfacial tension, temperature
Under what conditions is the formation of lysinoalanine favored in foods?
alkaline treatment of proteins
What is Raoult’s law?
vapor pressure of a solution = vapor pressure of the solvent x mole of solvent fraction
Smoke point comparisons of oils: canola, grapeseed, sunflower, safflower, olive
Safflower (510) Canola (460) Sunflower (450) Grapeseed (420) Olive (410)
What year was the Maillard reaction discovered?
1912
Depot fats and related animal fats are characterized by their high content of which fatty acids?
primarily C16 – C18 saturated, and C18:1 and C18:2
How many carbon atoms are in one molecule of beta-carotene?
40 (most carotenoids are made up of 8 isoprene units)
List four main functional properties of egg protein.
Solubility, emulsification, foaming, gelling
What are the described flavors of the following 3 compounds? Diacetyl, acetaldehyde, 1-octen-3-ol
Diacetyl – butter, acetaldehyde – nutty or apple, 1-octen-3-ol – mushroom
What does IUPAC stand for?
Int union of pure and applied chemists
What is a monosaccharide. A) polyalcohol b) poly acid c) polyether d) all of the above
A
What common enzyme can be used to modify lipids from their original triacylglycerol form?
Lipase
What is the enzyme that reacts with phospholipids?
Phospholipases
What is the bitter component of grapefruit called?
naringen
What is the smoke point temperature for fat?
442 deg F
Which fatty acid would be expected to have the highest iodine value - linoleic, oleic, or ricinoleic acid?
linoleic acid
Stability of eggs not dependent on: Protein conc, pH, H2O addition, presence of sugar
H2O addition
If you take 20 mL of a 0.1M NaOH salutation to titrate 40 mL of an HCL solution to the phenolphthalein end point. What is the molarity of the HCL solution?
0.05M HCL
What is the principle flavor compound in hazelnuts?
Filbertone
Name 5 chelating agents used in the food industry.
EDTA, citric acid, malic acid, tartaric acid, oxalic acid, succinic acid, adenosine triphosphate, pyrophosphate, porphyrins, and proteins
Three main polymorphic forms of fats.
Alpha, beta prime, beta
What are the holes in Swiss cheese caused by and what are they called?
Carbon dioxide and they are called eyes.
With regard to protein gelation, define thermally irreversible gel and thermally reversible gel. Give the predominant type of inter protein bonding and an example of food gels in each classification
A thermally reversible gel forms upon cooling after heating; hydrogen bonding is primary; gelatin is an example. A thermally irreversible gel forms during heating; covalent (disulfides) is primary bonding; examples include egg white, whey protein, soy protein, etc.
Name 2 nonenzymatic browning reactions.
Caramelization and Maillard
What kind of emulsion system is butter?
W/O
Which approved sweetener has the greatest sweetness relative to sugar?
Neotame (8000x ave.)
Hydrolysis of RNA with 5-phosphodiesterase yields 5-nucleotides that are used in the food industry as ______________________.
flavor enhancers, GMP, IMP
Common names of following fatty acids:
4: Butyric, 8: Caprylic, 12: Lauric, 16: Palmitic, 20: Arachadic
What is another name for yellow #5?
Tartrazine
Solanine found in bittersweet nightshade is a toxin belonging to what chemical compound family?
glycoalkaloids
How do sodium chloride and sucrose affect foam stability?
sodium chloride reduces foam stability and sucrose improves foam stability
What are four ways to inhibit enzymatic browning?
Decrease pH, HPP, addition of sulfites, addition of antioxidants, chelation of copper, prevent exposure to oxygen, MAP, freezing, dehydration
Name 5 primary functions of food thickeners.
Thickening, emulsion stabilization, suspending, gelation, crystallization, water binding, mouth feel, foam stabilization, flavor fixation, film formation
What is the common name of a 16:0 saturated fatty acid?
Palmitic
The temperature at which water boils_______ as elevation increases?
Decreases
What are five functions of surfactants in foods?
emulsification, aeration and foam stabilization, prevention of starch complexing, protein interaction and fat crystal modification
What does TBHQ stand for and what is its function in food?
Tertiary butylhydroquinone, it is used as an antioxidant in fats and oils
Name 3 components that effect water activity in a food product.
Solute concentration, moisture concentration, temperature
How many water molcules can one water molecule bind to?
4
What is the primary alkaloid found in cocoa and chocolate?
Theobromine
The products of superoxide ion O2-dismutation are ___________
3 O2 and H2O2
What is the difference between a high-methoxyl pectin and low methoxyl pectin?
High-methoxyl pectin requires a significant amount of sugar to gel properly, but low-methoxyl pectin requires less.
Name 5 non-caloric sweeteners with the chemical name and common name.
cyclamate = Sucaryl Saccharin – Sweet n Low, E954 Acesulfame-Potassium = Ace-K, E950, Sunett, Sweet One Aspartame = Nutrasweet, Equal Sucralose = Splenda Rebaudioside A = Stevias, Reb-A, Pure Via, Truvia Monkfruit sweetener (mogrosides) = Nectresse
What does the acronym EDTA stand for?
ethylenediaminetetraacetate
What is the 1st chemical preservative approved for use by the US food and drug administration?
sodium benzoate
What is the difference between rennet and rennin?
rennet - the commercial extract from cleaned, frozen, and dried 4th stomach of calves, kids, or lamb. Rennin - the actual enzyme (known as chymosin)
What kind of an emulsion is mayonnaise?
oil in water (o/w)
Why do O-H covalent bonds have partial ionic character?
because the oxygen molecule is highly electronegative
The combination of wintergreen, vanilla, and cassis (cinnamon) make up this commonly recognized flavor
Bubblegum
What is the major fatty acid in soybeans?
linoleic acid
As temperature increases, what happens to the density of a solution?
Decrease
What is the common name for sodium chloride?
Salt
What is FAD?
Flavin adenine dinucleotide
Name the 3 positively charged amino acids.
lysine, arginine, and histidine
What is the name of the reaction when an acid and base react to give water?
Neutralization
Name four bonds involved in tertiary structure of protein.
Hydrophobic, ionic, hydrogen, disulfide
Which is an mg determinant of cellulose fermentation in gut? a. ratio of cellulose:hemicellulose, b. ratio of lignan:cellulose, c. ratio of cellulose:resistant, d. ratio of mixing on inoculation
b. ratio of lignan:cellulose
What are two examples of natural antioxidants?
vitamin C, vitamin E, beta carotene
Name the fatty acid commonly associated with butter?
Butyric acid
For the D configuration of sugars, the reference hydroxyl group is on the _________ side in fischer projection formulas.
right
What is syneresis?
the extraction or expulsion of a liquid from a gel.
What flavor compound in amaretto?
Benzaldehyde
This recently approved (1996) non-caloric fat substitute is a mixture of hexa, hepta, and octa esters formed from the reaction of sucrose with long chain fatty acids
Olestra
Thermal treatment of Ginger will give
Shogaol and gingerone
What is the first law of thermodynamics?
the total energy of a system and its surroundings must remain constant, although it may be changed from one form to another.
What does the iodine value tell you about fat and what physical state is most likely for a lipid with a high iodine number at room temperature?
iodine value refers to the degree of unsaturated fatty acids in a lipid or the number of grams of iodine absorbed by 100g of fat. A high iodine value is associated with an unsaturated fat, which is typically liquid at room temp.
What are the coenzyme forms of niacin?
NAD, NADP
What substance is formed when collagen is heated in the presence in water?
gelatin
What is the most effective synthetic antioxidant?
TBHQ
What are the six colors of teas?
White, black, green, yellow, bluegreen, another type of yellow
t/f an oil in water emulsion is best achieved with an emulsifier having a low HLB value.
False
What organic acids are associated with the following fruits? Apples, grapes and oranges
apples – malic acid, grapes – tartaric acid, oranges – citric acid
What is one of the most bitter natural compounds known?
Amarogentin
Combustion of 10 g of food in a bomb calorimeter increases the temperature of 1 kg of water by 5°C. How many calories are present in 100 g of this food?
50 (kcal)
What percent of the O-H bond in a water molecule is ionic character?
0.4
Name three anticaking agents.
Tricalcium phosphate, Mg silicate, silicon dioxide, magnesium carbonate and iron ammonium citrate
Name 2 straight chain polyhydric alcohols used as food additives
sorbitol - modifying agent, humectant, flavor, and crystal modifier; mannitol - flavor modifier, inert base
Name 3 enzymes that work on pectin.
Polygalacturonase, Pectin lyase, Pectin methyl easterase
The pigment found in some plants which is characterized by the ligand structure known as a porphyrin with magnesium at the center is
Chlorophyll
When does buffering occur in foods?
when a weak acid and a salt (its conjugate base) are present in the same food
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