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What milk is Koumis made of?
Horse or mare's milk
What is the enzyme added to milk that hydrolyzes the glycosidic bond in lactose, making it easier to digest for lactose-intolerant individuals?
Lactase
Legally, cheese must be aged for at least how many days if produced using raw milk?
60 days
A gritty texture in ice cream is due to what?
Lactose crystallization
What is rennin?
Proteolytic enzyme from the stomach of suckling calves.
What is the concentration of casein in human milk compared to cow milk?
Lower concentration
What animal's milk is commonly used to produce Roquefort cheese?
Lacaune sheep
What is the major fatty acid found in milk?
Palmitic acid, Oleic acid
What makes cow's milk appear white?
Casein micelles and fat, which scatter light
You wanted Penicillium camemberti to grow on the surface of your Brie cheese, but Penicillium nalgiovense grew instead. What color is the surface of your cheese?
Pinkish-white
By volume, what is the most consumed dairy product around the world?
Milk
List two methods for making cheese.
Rennin (enzyme) and adding acid (lowering pH)
What food product is B-lactoglobulin and alpha-lactalbumin found in?
Milk
What process involves forcing milk through a small orifice at high pressure to break down fat globules, preventing cream separation?
Homogenization
Name three mold ripened cheeses.
Roquefort: Penicillium roqueforti (Blue mold) Brie: Penicillium camemberti (White mold) Camembert: Penicillium camemberti (White mold) Gorgonzola: Penicillium roqueforti (Blue mold) Stilton: Penicillium roqueforti (Blue mold) Fourme d'Ambert: Penicillium roqueforti (Blue mold) Cabrales: Penicillium roqueforti (Blue mold) Danablu: : Penicillium roqueforti (Blue mold)
Under what major enzyme classification does the enzyme chymosin (used in the manufacture of rennet coagulated cheeses) fall?
Hydrolase/protease; chymosin is an acid protease like pepsin, it breaks peptide bonds through hydrolysis reaction
What is the white color and yellow color of milk due to?
Whiteness is due to scattering of light by casein micelles and fat globules; yellow is due to fat-soluble pigments such as carotenoids.
Sour cream is caused by a denaturation of what protein in milk?
Casein
Name three alternate names for clotted cream.
Devonshire, Cornish, Scalded
With regards to dairy products, RBSA stands for?
Recombinant bovine serum albumin
The lactic acid in cheese is made from what compound?
Lactose, through bacterial fermentation
What is the name of milk containing between 10.5%-18% milk fat?
Half and Half
What manufacturing process is responsible for the loss of vitamin A when skim milk is made?
Centrifugation, or separation (of cream)
Differentiate between evaporated and condensed milks.
Condensed milk is processed similarly to evaporated milk except it may be homogenized and/or vitamin D fortified; it is not subjected to further heat treatment.
what 2 microorganisms are the principal acid producers in the manufacture of sour cream?
Lactococcus lactis spp cremoris and Lactococcus lactis ssp lactis
Define titratable acidity of milk and milk products.
Titratable acidity refers to the total amount of acid present in milk, both free hydrogen ions and those bound in weak acids, measured by titration with a standard alkali (usually NaOH). It indicates the freshness and microbial activity in the milk. It is expressed in degrees Dornic (°D), Thorner (°T), or as a percentage of lactic acid (e.g., 0.14–0.17% for fresh milk). This test is used to determine milk quality and to monitor fermentation of cheeses.
Rice and Almond milk are good sources of protein, similar to the amount of protein in dairy milk.
False
Stirred yogurt and fruit at the bottom are the two common types of yogurts. In which type does fermentation take place in the container?
Fruit at the bottom
On average how much casein is in sheep’s milk?
4-5%
Mozzarella cheese is now commonly made with cow's milk. Traditionally, mozzarella was made from what type of milk and in what country?
Water buffalo's milk in Italy
What is the name of milk containing between 30%-36% milk fat?
Whipping Cream
Roese-Gottlieb, Mojonnier, and Babcock tests are commonly used to determine what constituent of milk?
Fat
Pasteurization standards for milk were originally designed to destroy what and are currently designed to destroy what?
Mycobacterium tuberculosis Coxiella burnetii
Min fat % according to SOI: Butter, whole milk, cottage cheese, cream cheese
Butter: 80%, whole milk: 3.25%, cream cheese: 33%, cottage cheese: 4%
Give two examples of yeast-lactic fermented milk products.
Kefir and Koumis
What is the predominant protein found in Gouda cheese?
Caesin
Which organisms generally make up the lactic acid starter culture used in cottage cheese production?
Lactococcus lactis subsp. lactis Lactococcus lactis subsp. cremoris
What process sweetens Gouda?
Washing the curd
What is the Kjeldahl factor for dairy products?
6.38
The major action of proteolytic enzyme rennet on milk proteins is the cleavage of k-casein yielding glycomacropeptide and an insoluble portion called what?
Para-κ-casein
In the US, cultured butter is also known as what?
European-style Butter
What test is used to monitor changes in the acidity of cultured milk products?
Titratable acidity expressed as percent lactic acid
Which milk protein is primarily responsible for cheese curd formation?
Casein.
Cooked flavor of milk after thermal processing is because of?
Release of sulfur compounds
Which is not a form of casein found in milk: Beta, alpha, kappa, sigma, or gamma?
Sigma
What is the name of naturally occurring antimicrobial system in milk consisting of 3 components, 2 of which are thiocyanate and hydrogen peroxide?
Lactoperoxidase system (LP-System)
Cheese was the first made about 4000 years ago on what continent?
Asia
You are trying to pasteurize milk to reduce the amount of E. coli. If you are treating the milk for 15 seconds what temperature is needed?
161 deg F or 72 deg C
What is the primary whey protein that is denatured by heat during milk pasteurization and contributes to the cooked flavor?
beta-lactoglobulin
When whey proteins are heated, what three changes can be observed? What are three effects of high temperatures on whey proteins?
Coagulation, denaturation, maillard browning, and sulfide groups are released (cooked flavor development)
According to Codex Alimentarius, what is the minimum percentage of fat required in cream and prepared cream?
0.1
How is buttermilk made?
Cow's milk is inoculated with lactic acid bacteria (usually either Lactobacillus lactis or L. bulgaricus), or buttermilk can refer to the liquid leftover after making butter from cream
Name a fermented milk containing alcohol.
Kefir
Which cheese is made from the by-product of cheese production?
Ricotta Cheese
Cheese fruits commonly come from what type?
Pomes
What is the hormone responsible for milk let down in cows and from which gland is it secreted?
Oxytocin; pituitary gland
Butter gets its name from what compound found in rancid butter?
Butyric Acid
The eye of Swiss cheese is due to carbon dioxide.
True
Which dairy breed of cow averages the highest fat content of raw milk?: A.Holstein, B.Guernsey, C. Ayrshire, or D. Jersey
D. Jersey
According to the Pasteurized Milk Ordinance, what is the maximum number of microorganisms allowed in un-pooled raw, Grade A milk?
100,000 CFU/ml
What milk type is characterized as milk with 2% milk fat?
Reduced Fat Milk
What genus of lactic acid bacteria contains both homo- and heterofermentative species?
Lactobacillus sp.
What is the main fatty acid in butter?
Butyric acid
Coatings such as waxes in cheese and casings in sausages are used to prevent migration of which component?
Water
What are the three bacteria used in the production of Swiss cheese?
Streptococcus thermophilus, Lactobacillus helveticus, and Propionibacterium freudenreichii shermanii
What is the normal freezing point of milk?
-0.530°C (range from -0.512 to -0.550°C is acceptable)
What is the name of cream that has been fermented with lactic acid bacteria?
Sour cream or crème fraîche (depending on fat content and culture)
What does the following equation define? (Volume of ice cream - volume of mix / volume of mix) X 100
Percent overrun of an ice cream
What process is used to separate the lipid and solid content to achieve a uniform fat concentration in milk?
Homogenization
What is the pH of milk?
6.6-6.8
What is used as the heating medium in a direct UHT milk processing system?
Steam
According to FDA SOI, low fat milk should have what percentage by weight of milk fats?
0.5-2%
What is made from fermenting leftover liquid after churning butter?
Buttermilk
Name the four major categories of cheese.
Soft unripened, soft ripened, semi soft ripened, and hard
What cheese has the most moisture?
Cottage cheese
Rank the following animals in average milk fat content: cow, sheep, goat, water buffalo, reindeer, camel.
(low to highest) Camel, cow, goat, sheep, water buffao, reindeer
How did cheese-makers overcome the kosher problem of rennet?
Its produced from a microbiological source as chymosin
Name the key bacteria in Yakult.
Lacticaseibacillus casei Shirota
In what salt form is calcium most readily solubilized for addition to foods for fortification?
Ca caseinates or whey fractions Other forms commonly used -> Ca carbonate: used in fortified foods Ca lactate: organic source, used as supplement Ca citrate: most common over-the-counter supplement
What is the function of gelatin in an ice cream mix?
Stabilization. It retards ice crystal formation during frozen storage of the finished product by binding water.
What is the name of butter that has dimensions of 3.25, 1.5, 1.5 inches?
Western-style butter stick/ stick butter
What is a typical range for the amount of protein found in cow's milk?
Approximately 30-35 grams/liter (3 to 4%)
In addition to protein, casein micelles contain 6-8%: A) lactose B) calcium phosphate C) lactoglobulin
B) calcium phosphate
In cheesemaking, what is the solid protein mass called that is separated from the liquid whey?
Curd
What happens when a natural cheese is heated to a high temperature?
Stringiness, toughness, and separation of fat
What is the breed of dairy cow that produces milk containing the highest percentage of milk fat and milk protein?
Jersey
Describe three functions of emulsifiers in ice cream.
Form small droplets following homogenization, partially stabilize fat emulsion during aging, partial coalescence of fat during freezing aiding in air entrapment
In fermentation by lactic acid bacteria, which enzyme is important for the hydrolysis of lactose into galactose and glucose?
β-galactosidase/ lactase
What animal has been called "the poor man's cow"?
The goat
Why is yogurt processed at elevated temperatures?
The yogurt is incubated at a higher temperature because L. bulgaricus and Strep. Thermophilus are thermophiles
Whey protein concentrate (WPC) is produced with three different protein percentages. What are they?
34%, 50%, 80%.
Cow's milk normally has how much lactose?
5% by weight
Name the three genera of lactic acid producing bacteria important in fermented dairy products?
Lactococcus, Lactobacillus, and Leuconostoc
What is the country of origin of Primost cheese?
Norway
Russia produces more milk than the U.S.A.
False
What is the substrate for the phosphatase test in milk?
Disodium phenyl phosphate (or p-nitrophenyl phosphate in modern versions)
What is a name of sour cream that is higher in fat content and less sour?
Crème fraîche
What is the most variable compositional component of milk?
Milkfat
What process is most effective in removing proteins from whey?
Ultrafiltration or microfiltration
What type of edam matches well with peaches, melons, and apricots?
Mild, young Edam
Kulfi is a delicious, milk-based, frozen dessert. What country is Kulfi native to?
India
What two regions commonly use sweet cream butter?
UK, North America
Stirred yogurt is one of the two common types of yogurts. Name the other.
Set yogurt/ firm yogurt
Name a non-milk dairy product that the Pasteurized Milk Ordinance regulates?
Grade "A" Condensed and Dry Milk Products, Condensed and Dry Whey, Cream, such as half & half or light cream
The most expensive cheese in the world is made from milk from what animal?
Balkan donkey (used to make Pule cheese in Serbia)
Milk is unusual because about 12% of the fatty acids are which of the following? a) Unsaturated b) Short-chain c) Long-chain
Short-chain
What is the first milk of cows, usually discarded?
Colostrum
What is the term used for Dulce de Leche in France, translating to milk jam?
Confiture de lait
In which dairy products is acetaldehyde a problem or defect?
Any milk product other than yogurt
What is the name of semi-hard cheese from the Netherlands, packaged in red paraffin wax?
Edam
What type of bacteria are responsible for the sour taste in yogurt?
Lactic acid bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus).
What casein fraction is most sensitive to chymosin cleavage during cheese manufacture?
κ-casein.
What is the active enzyme in rennet? And what does it do to milk?
Chymosin - breaks down the milk protein casein to paracasein which combines with ca to form calcium paracaseinate which separates out
What is butter without salt called?
Unsalted butter or sweet cream butter
What gives skim milk a slight bluish tint?
Scattering of light by casein micelles and the absence of fat, which normally masks this effect
Name the animal drug approved for increased milk production in dairy cattle.
Recombinant Bovine Somatotropin (rBST or rBGH)
Skim milk has a bluish tint due to the scattering of light by what component?
Casein micelles
What is the largest dairy farmer cooperative and what does it stand for?
DFA= Dairy Farmers of America
What is the defect in milk called when it develops a "cardboardy" or "painty" flavor due to the oxidation of unsaturated fatty acids?
Oxidative Rancidity
What breed of cow produces the most milk in the United States?
Holstein
What is the pI of casein?
4.6
What does MFGM stand for wrt milk?
Milk Fat Globule Membrane
The two microorganisms present in A/B type milk are what?
Lactobacillus acidophilus and Bifidobacterium bifidum (accept L. acidophilus and Bifidobacterium spp.)
Name the protein that stabilizes the casein micelle.
κ-casein
What is the cause of sunlight flavor in milk?
Photoxidation (oxidation of methionine to methional by photoactivated riboflavin); it gives an oxidized flavor and is often confused with lipid oxidation
Which enzyme is used in cheese making to cleave κ-casein?
Chymosin.
Describe the composition of clarified butter.
Purified butterfat with water and milk solids removed
Name the types of whey from cottage, Parmesan, cheddar, ricotta, and Swiss cheese production.
Cottage: Acid Parmesan: Sweet Cheddar: Sweet Ricotta: Acid Swiss: Sweet
In what food is butyric acid typically found?
Milk
If fluid milk is priced at $10 per 100lb, how much does the water cost in the milk?
milk is 87% water, so $8.70
What company developed American cheese?
Kraft
Which of the following cheeses has the highest % of calcium: A.Parmesan, B.Swiss, C.Cheddar, or D.Limburger?
A. Parmesan
What type of edam is eaten with cheese fruits?
Aged Edam
What milk type is characterized as fresh, unpasteruized milk straight from the cow?
Raw Milk
What was the original intent of salting butter?
Preservation
According to FAO, what is the % of fat in yak's milk?
5-7%
According to FDA SOI, ice cream should have what minimum percentage by weight of milk fat?
0.1
What is direct acid set cottage cheese?
Cottage cheese made with food grade organic acids rather than bacterial starter cultures
What do you call the metal ions in dairy products that accelerate the deterioration and development of off-flavors?
Prooxidants
What is the general bacterial limit for Grade A pasteurized milk?
20,000 CFU/ml
Lactococcus lactis, Lactococcus lactis subsp. cremoris, and Lactobacillus delbrueckii subsp. bulgaricus, are cheese starter organisms. Which of them has the highest temperature for optimum growth?
Lactobacillus delbrueckii subsp. Bulgaricus
What is the average specific gravity of milk?
1.032
Myost, Primost, Gjetost, and Ricotta are all cheese manufactured from what starting material?
Whey
In Ice cream production, what term is used used for the first step of formation of ice crystals?
Nucleation
Discuss the role of starter cultures in fermented dairy products.
Starter cultures initiate controlled fermentation by converting lactose to lactic acid, lowering pH, improving safety, texture, and flavor. They also influence aroma compound formation and may contribute probiotic benefits depending on the strains used.
What compound is commonly used to color cheese?
Annatto Extract
What is the average composition of unprocessed milk? (Within 0.2%)
4.8-5.0% lactose, 3.5-3.7% fat, 3.3% protein, 0.7% minerals or 0.6% ash, 87.5% water
What defect in ice cream is caused by ice crystal formation?
Coarseness or sandiness
If freezing point of milk is close to 0°C, what has happened?
It is adulterated with water
What is the compound responsible for the strong aroma of blue cheeses?
2-heptanone and 2-nonanone
What causes the yellow-green pigment of skim milk and whey?
Riboflavin
Which protein denatures at a lower temp: Beta-Lactoglobulin or Alpha-lactalbumin?
Alpha-lactalbumin is more thermally labile, but protein denaturation depends also on pH.
What are 2 ways milk is dried into powder form?
Spray drying and drum roller drying
What product consists of pasteurized milk or low-fat milk inoculated with Lactobacillus acidophilus believed to provide health benefits?
Acidophilus milk or sweet acidophilus milk (when not incubated)
What is the name of the milk product that removes fat and water from milk?
Milk Powder, specifically nonfat dry milk (NFDM)
What is found in the gastric juice of a mammal's stomach from which the common enzyme rennin is extracted?
Rennet (not rennin)
Which of the following foods does not have a standard of identity? a) Cheddar cheese b) Mayonnaise c) Frozen yogurt d) Ketchup
c) Frozen yogurt
Name the by-product of the manufacture of most cheeses.
Whey
What minor compound in bovine milk is used as a standard in protein assays?
BSA
What is the major reason that copper should not be used in food processing equipment, especially in dairy plants?
Copper acts as a strong oxidizing agent and promotes oxidative rancidity
What cheese is associated with Propionibacterium shermanii?
Swiss Cheese
What's the liquid used in cheese production?
Whey
What does ADSA stand for wrt dairy science?
American Dairy Science Association
What is the minimum fat content of clotted cream?
0.55
What is the main sugar in whey?
Lactose
What does the acronym PMO stand for wrt dairy processing and is it required?
PMO - Pasteurized Milk Ordinance; it is not required
Why is Vitamin A added to skim milk?
Because Vitamin A is removed with the cream
Name the compound responsible for the characteristic buttery flavor of fermented dairy foods.
Diacetyl
Why should antibiotics be excluded from the milk supply?
They could cause allergic reactions if milk is ingested, they could destroy the organisms used in cultured dairy products, and they can cause antibiotic resistance in pathogenic organisms
What is the difference between mellorine and ice cream?
Mellorine contains essentially the same ingredients as ice cream; however, the milk fat is replaced with another fat, usually vegetable fat
What color is yak's milk?
White to slightly bluish-white
Which proteins in milk are coagulated and precipitated by boiling?
Lactalbumin and serum globulin
Discuss the chemistry of yogurt fermentation, including starter cultures and acid-induced gel formation.
Yogurt fermentation uses Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, which convert lactose into lactic acid. Acidification lowers pH toward the isoelectric point of casein, causing protein aggregation and gel formation, producing yogurt’s texture and flavor.
Name four additives that are legal for use in making cheese.
Rennet, annatto, calcium chloride, and starter culture
The components of cow's milk that do not vary much with the age of the cow, diet, breed, and stage of lactation are which of the following? A) water and protein B) minerals and carbohydrate C) lipids and carotenoids
A) water and protein
Cheese is categorized by what two factors?
Ripeness and hardness
What product did William Horlick discover and produce?
Malted milk powder
Is Brie cheese classified as soft unripened, soft ripened, or semi soft ripened?
Soft ripened
What is the main difference in composition between soft and hard cheese?
Moisture content
What effect causes recrystallization in ice cream?
Ostwald Ripening
There are many ways to classify cheese. Name 2 classification methods and 3 different categories within each classification.
By Milk Source Cow's Milk: Example: Cheddar, Gouda, Brie Goat's Milk: Example: Chèvre, Garrotxa, Crottin de Chavignol Sheep's Milk: Example: Pecorino, Roquefort, Manchego By Moisture Content Soft Cheese (High Moisture): Example: Brie, Camembert, Ricotta Semi-Hard Cheese: Example: Gouda, Edam, Gruyère Hard Cheese (Low Moisture): Example: Parmesan, Pecorino Romano, Grana Padano By Aging Process Fresh Cheese (Unaged): Example: Ricotta, Mozzarella, Feta Aged Cheese (Matured): Example: Cheddar, Comté, Gouda Blue Cheese: Example: Roquefort, Gorgonzola, Stilton (aged with mold development) By Texture Creamy Cheese: Example: Brie, Camembert, Cream Cheese Firm Cheese: Example: Swiss, Cheddar, Emmental Crumbly Cheese: Example: Feta, Cotija, Roquefort By Production Method Rennet-Coagulated Cheese: Example: Cheddar, Parmesan, Gouda Acid-Coagulated Cheese: Example: Ricotta, Paneer, Queso Blanco Mold-Ripened Cheese: Example: Camembert, Roquefort, Blue Stilton
Other than water, what component is present in the highest percentage in milk?
Lactose (5%)
What position of κ-casein does the enzyme rennet cleave?
Phenylalanine (105) - Methionine (106)
Name the two molds primarily responsible for blue cheeses.
Penicillium roqueforti, Penicillium glaucum
What is the chief whey or serum protein in cow's milk?
β-lactoglobulin
What is the first degree breed of dairy cattle in the US?
Holstein
How much cholesterol is found in 100g of whole milk?
10 mg
Washing the curd removes what compound?
Lactose (along with some whey proteins and minerals)
Give two reasons why deaeration of cream is required to produce high quality butter.
To remove undesirable taste and flavor compounds, to prevent growth of aerobic bacteria, fat oxidation
Like Roquefort and Stilton, which of the following is also a blue cheese: A.Coloumiers, B.Tallegio, C.Braun, or D.Maytag?
D. Maytag
What is the enzyme in milk that causes hydrolytic rancidity?
Lipase
List the 6 typical stages for making cheese.
Acidification Coagulation Curd cutting Add salt Molding/forming aging
What term describes the process of matting and subsequent handling of matted curd in the production of Cheddar-type cheese?
Cheddaring
What is the name for the Fresh Cheese that translates to "White Cheese" in French?
Fromage Blanc
If the freezing point of milk is closer to zero degrees C, what could be the cause?
Adulteration with water
For what city in Wisconsin is Colby cheese named?
Colby, Wisconsin
Cheddar cheese produces what kind of whey?
Sweet whey
What is the difference between traditional, or true, buttermilk and cultured buttermilk?
Traditional buttermilk is the liquid leftover after churning cream into butter and cultured buttermilk is skim milk cultured with Lactobacillus lactis or Lactobacillus bulgaricus.
Low temperature storage of ice cream promotes the formation of lactose crystals. This will cause the ice cream to be:
Gritty or sandy
What is the anti-sticking agent approved by the FDA that can be added to processed cheese?
Powdered cellulose or calcium phosphate
What milk product did the U.S. Agriculture Department propose as a substitute for meat in school lunches in 1996?
Yogurt
Which cows produce milk with higher fat content: Holsteins or Jerseys?
Jerseys.
What milk type is characterized as milk with 1% milk fat?
Low Fat Milk
Cooked flavor develops in milk when what compound is released by heat?
Hydrogen sulfide
The genus of psychrotrophic bacteria associated with flavor defects in refrigerated milk?
Pseudomonas
What is the correct placement of the main or timing pump for the pasteurization of milk with respect to the regeneration and heating sections?
The main pump must be placed after the generation section, but before the heating section
What product consists of pasteurized milk or low-fat milk coagulated to a custard-like consistency with a mixed lactic acid culture containing Lactobacillus bulgaricus and Streptococcus thermophilus?
Yogurt
What characteristic acid is formed during Swiss cheese fermentation?
Propionic Acid
Explain the process of homogenization and its purpose in milk processing.
Homogenization mechanically breaks down fat globules into smaller sizes, preventing creaming and creating a stable dispersion, improving texture and appearance.
According to federal standards, 1 pound of evaporated milk is equivalent to how many pounds of fluid milk?
12
What is the name of the dairy product made by the fat and protein of churned cream?
Butter
What are the consequences when milk is overheated?
Denaturation/coagulation, flavor deterioration (cooked or burnt taste), nutrient loss and sulfur release
On a weight percent basis, what are the two predominant fatty acids in cow's milk?
Palmitic (24-26%) and oleic (34-38%)
What is the country of origin of Gouda cheese?
Netherlands
What is the protein content of acid whey?
0.6-1.2% by weight
Which of these would be heaviest: a gallon of whole milk, a gallon of skim milk, or a gallon of whipping cream?
Skim Milk
Name a cheese made from the byproduct of most other cheeses' production.
Ricotta, myost, primost, gjetost, anari, mató, brocciu, etc.
What is cheddaring?
The process where matted cheese curd is cut into blocks, stacked, and drained of whey.
What is the minimum time and temperature for batch, LTLT, or vat pasteurized milk?
145°F or 63°C, 30 min
What is the primary sugar naturally found in milk?
Lactose
What is the primary carbohydrate found in bovine milk, which is a disaccharide composed of glucose and galactose?
Lactose
Which protein in milk micellar structure is not affected by Ca+?
K-casein
What defect is caused by lactose crystal formation in ice cream?
Sandiness
What process prevents cream separation in milk?
Homogenization.
What is the fur-like appearance of surface ripened cheeses caused by?
Excessive mycelia growth of molds
According to FDA SOI, reduced fat milk should have what percentage by weight of milk fats?
1.5-2%
What is the normal pH of milk? a. 6.2-6.4 b. 6.5-6.8 c. 7.0-7.3 d. 7.4-7.6
b. 6.5-6.8
What milk protein is responsible for iron binding and enhanced iron adsorption into the body?
Lactoferrin
Which amino acid lies at the 105th position on kappa casein, which is the cleavage point for chymosin during renneting?
Phenylalanine
Who developed the first standardized test for quantifying milkfat?
Stephen M. Babcock at the University of Wisconsin (1890)
Which of the following is an example of a wash rind cheese? a) Limburger b) Brie c) Roquefort d) Munster
a) Limburger
Name two molds used in white mold cheese production.
Penicillium camemberti, Geotrichum candidum, Scopulariopsis candida (rare)
What disaccharide typically accounts for approximately 70% of whey solids and is of major commercial significance?
Lactose
Name the thermal processing method used to destroy the pathogenic organisms and extend the shelf life in milk.
Pasteurization
What mold provides characteristic blue veins in cheese?
Penicillium roqueforti
What % fat in bovine milk exists as TAGs? a. 83% b. 88% c. 93% d. 98%
d. 98%
Half and half signals what two ingredients?
Light Cream and whole milk
According to FDA SOI, whole milk should have what minimum percentage by weight of milk solids-not-fat (SNF)?
0.0825
What 2 products does milk separate into during the production of cheese?
Whey and Curd
What amino acid is most responsible for off-flavor development in milk?
Methionine
Milk fat globule membranes are a trilayer made of what three compounds?
Polar lipids, cholesterol, protein
What enzyme is used as the measure of adequate pasteurization of milk product: A.peroxidase, B.protease, C.alkaline phosphatase, or D.catalase?
C. alkaline phosphatase
Riboflavin makes whey appear what color?
Greenish-yellow or Green
What compound is produced by chemical isomerization of lactose?
Lactulose
What is the process that keeps milk fat from floating atop the liquid component of milk?
Homogenization
Name 5 active compounds in Gouda cheese.
Diacetyl, 3-methylbutanal, methional, ethyl butyrate, acetic acid, 2-methylbutanal
How can casein be separated from whey proteins in milk?
Whey proteins are acid-stable and caseins are not; therefore add acid or microbial cultures to reduce pH to 4.6 where casein precipitates.
What causes ropiness defect in yogurt?
Production of exopolysaccharides (EPS) by certain strains of lactic acid bacteria, particularly Lactococcus lactis subsp. cremoris, Streptococcus thermophilus, and some Lactobacillus species.
What is the lactoferrin inhibitor in milk?
Citrate
pH of milk reflects the total acidity of milk.
False
What is the recognized standard method for detecting antibiotics in milk?
The disc assay (with Bacillus)
What cheese is associated w/ Penicillium roqueforti?
Blue Cheese
What enzyme deficiency causes lactose intolerance?
Lactase deficiency
What are the two major whey proteins in milk and what percentage of total milk protein do they make up together?
Beta-lactoglobulin & alpha-lactalbumin; together they make up about 20% of milk proteins.
Milk homogenization slows creaming by changing oil droplets radius.
True
Which of the following acts as a buffer in milk: A.citrates, B.Lactose, or C. NaCl?
A. citrates
This fluid contains almost 50% of the solids initially present in whole milk.
Whey
What state does the milk protein casein occur in milk, and what is its Zeta potential?
Casein occurs in colloidal dispersion phase in milk. Its zeta potential is about -18mV
Ayrshire, Brown Swiss, Guernsey, Holstein, and Jersey are animal breeds all considered primary sources of what food?
Milk
How does Mozarella get its stringiness?
Mozzarella’s stringiness comes from the pasta filata process, in which the curd is kneaded and stretched in hot water. This aligns the proteins into long fibers, giving the cheese its characteristic stretch.
What percentage of the fat in milk exists as triglycerides?
0.98
Which of the following are not used as fat replacers in ice cream? a) Alginate b) Pectinate c) Carboxymethyl cellulose d) Carrageenan e) All of the Above
e) All of the above
According to FDA SOI, low fat milk should have what minimum percentage by weight of milk solids-not-fat (SNF)?
0.0825
What caesin type reacts with the rennet?
Kappa caesin
What is the name of the process that converts lactose into lactic acid in yogurt production?
Fermentation by lactic acid bacteria (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus).
To what temperature must milk be cooled to within 2 hours after milking or after completion of milking?
45°F or 7°C (Grade "A" Pasteurized Milk Ordinance)
Name the 2 most famous 'molded' cheeses.
Roquefort and Camembert
Which of the following is the isoelectric point of casein:A.5.2, B.4.6, C.4.8, or D.5.6?
B. 4.6
Name the mold responsible for Brie cheese.
Penicillium camemberti
The alpha casein fraction of milk is now recognized to be a degradation product of what?
Beta casein
What ice cream type only uses cream, sugar, and flavoring?
Philadelphia-style/ American-style
What is the name of Fromage Blanc in which there are live cultures?
Fromage Frais
What is the name of Dulce de Leche in Phillippines is made with carabao milk?
Dulce Gatas/ Pastillas de Leche
What is added to Skim milk & whey to give it a yellow pigment?
Vitamin B2 (Riboflavin)/ annato extract
The protein in milk that precipitates at pH 4.6 is:
Casein
France has over how many different types of cheeses?
1600
What vitamin is permitted as a food color in milk?
Riboflavin (vitamin B2)
Butter without culture is called what?
Sweet cream butter
Name the sugar found only in milk.
Lactose
The detection of coliforms in a sample of pasteurized milk purchased from the grocery store would indicate what about the milk?
Probably post-pasteurization contamination (inadequate pasteurization is also acceptable).
Which defect in milk causes coagulation during high-heat processing due to mineral imbalance?
Heat instability.
According to U.S. federal regulations, the weight of one gallon of ice cream must be a minimum of:
4.5 pounds
What is the part in a milk pasteurizer where hot milk is in contact with cold milk?
Regenerator (regeneration section or part; holding tube is incorrect)
What are the two main cattle breeds for milk?
Holstein, Jersey
Which cows produce the most milk? A) Jerseys B) Guernseys C) Holsteins
C) Holsteins.
Milk is an excellent source of many vitamins and minerals. It does not contain significant amounts of:
Vitamin C and iron
The compound responsible for the characteristic buttery flavor of fermented dairy foods is what?
Diacetyl
What is the primary protein in milk?
Casein
What are two major reasons for pasteurizing milk?
Destroy pathogenic organisms and increase shelf life by destroying spoilage organisms
Why is goat's milk more pungent than cow's milk?
It contains more short chain fatty acids that cow's milk.
What is the name of the bacterium used for surface ripening in Limburger Cheese?
Brevibacterium linens
What is the most common cause of slow or dead vat that prevents normal ripening in cheese production?
Bacteriophage infection of lactic acid bacteria
What is the name given to the pasteurized milk product which has been concentrated and brought to approximately 63% sugar/solids?
Sweetened condensed milk
What ice cream company registered the slogan "Dedicated to Perfection"?
Häagen-Dazs
Which whey protein denatures and interacts with κ-casein during high-heat milk processing?
β-lactoglobulin.
What protein makes up the majority of milk protein?
Casein
Which is the enzyme that is tested to check for the pasteurization of milk?
Alkaline phosphatase
How can the taste of gouda cheese be altered?
Maturing time/by aging (longer aging creates a stronger, nuttier, and caramel-like flavor), and by smoking, adding herbs/spices, or adjusting milk composition
Which contains less butterfat: whole cream, light cream, or half & half?
Half & half
What type of whey is produced during the manufacture of Cheddar cheese?
Sweet whey
What is the naturally occurring antimicrobial chemical in Swiss cheese?
Propionate or propionic acid
What is filmjolk?
Fermented milk produced using "ropy" strains of lactic acid bacteria such as Streptococcus cremoris. Nordic dairy product made from soured milk, similar to yogurt, but is produced using different bacteria and cultured at a lower temperature than yogurt (different taste and texture)
Which defect in milk is caused by psychrotrophic bacteria?
Bitterness.
Coconut milk contains saturated fat in amounts similar to that found in whole cow's milk.
True
What is the name of Morroccan clarified butter that is spiced?
Smen
What is the common flavor defect found in milk exposed to light?
Light oxidized flavor, often described as metallic or cardboard-like
What mold is used in the ripening of Camembert cheese?
Penicillium camemberti
How do Roquefort and blue cheese differ?
Roquefort cheese must be made with Lacaune sheep milk and undergo its ripening period in the caves of Roquefort, France; Blue cheese is made similarly, but produced and ripened in any place other than Roquefort
What is kefir?
Fermented milk (goat, buffalo, or cow) produced using lactic acid bacteria (Streptococcus lactis, Lactobacillus bulgaricus, Leuconostoc cremoris, etc.) and yeasts (Saccharomyces kefir, Candida kefyr, Kluveromyces fragilis, etc.)
Milk is sometimes concentrated using RO and UF equipment; what do these abbreviations stand for?
RO = reverse osmosis ; UF = ultra filtration
What is the unit operation used to destroy pathogenic microorganisms in milk while causing minimal change to its nutritional and sensory properties?
Pasteurization
The high fat content of ice cream helps keep it smooth by decreasing ice crystals. Other ingredients that reduce ice crystals include:
Corn syrup or protein
The process of pasteurizing fluid dairy products by heating to 125-137.8C (257-280F) with a holding time of 2-5 sec to kill all pathogenic organisms, permitting storage at refrigerated temperature for an extended time is known as what?
UHT processing
What is the indicator organism to assess milk pasteurization?
Coxiella burnetii
Please list two method for making cheese.
1. rennin (renet) enzyme 2. addidng acid or lactate, lowering the pH to achieve pI of casein
The acid orange 12 dye-binding test is used to determine what in milk?
True protein content of milk
Name the first food for which microbiological standards were established.
Milk
How many cups of butter are there in one pound?
Two
In dairy cows, aflatoxin B1 can be ingested with feed. A small percentage of this toxin is metabolized and excreted in milk as what?
Aflatoxin M1
Why is lactose-free milk sweeter than regular milk?
Lactose converted to glucose + galactose
Cottage cheese and Ricotta produce what kind of whey?
Acid Whey
What enzyme is added to milk during cheese production to coagulate casein?
Rennet (chymosin).
How do lactose intolerance and milk allergy differ?
Lactose intolerance results from a lack of lactase, milk allergy is an autoimmune response to milk protein
Which protein in milk has a higher denaturation temperature?
Beta-lactoglobulin
What are the 4 major components of whey proteins?
Beta-lactoglobulin, Alpha-lactalbumen, glycomacropeptide, immunoglobulins (minor components: lactoferrin, bovine serum albumin (BSA), and various enzymes and peptides)
What is the main carbohydrate in milk?
Lactose.
Name 2 ways lactose is commonly isolated from whey.
Crystallization or nanofiltration
What is the most common yogurt flavor?
Strawberry
What is the most predominant component in milk?
Water
Name two unripened cheeses.
Cottage, cream, ricotta, farmers, Neufchatel, mozzarella, queso blanco, queso fresco, quark
Name a group of microaerophilic bacteria used in dairy food.
Lactobacillus, Streptococcus, or Leuconostoc
Name four types of cheeses that are ripened by mold.
White mold: Camembert, Brie, Coulommiers, Chaource, Neufchâtel Blue mold: Roquefort, Gorgonzola, Stilton, Blue cheese (generic), Danish Blue, Fourme d'Ambert, Cabrales Both blue and white: Cambozola
Kajmak, Cajeta, and Confiture de Lait are varieties of what milk product?
Dulce de Leche / Milk-based caramel or milk jam (concentrated, sweetened milk products cooked down to a thick, caramelized consistency)
Buffalo milk is what % of fat: A.20%, B.5%, C.8%, or D.who drinks buffalo milk?
C. 8% fat
A “Hard Cheese” must contain no more than what percent moisture?
0.39
In regards to cheese, what is an affineur?
Person who ages cheese
What milk protein is not synthesized in mammary glands but enters the milk through passive leakage through bloodstream?
BSA, bovine serum albumin
What's the primary difference between an ice-cream and a frozen dessert?
An ice-cream has milk fat while a frozen dessert has vegetable oil/fats.
How much fat does skim milk have?
0.5% or less
Define 'Cheddaring'.
Method used to drain off whey and develop texture and acidity; it is accomplished by slicing drained curds into large blocks which are stacked and turned every 15 minutes until a titratable acidity of 0.5-0.6 is reached
What enzyme in cheese will reduce diacetyl into acetoin?
Diacetyl reductase
What is the underlying principle to the test for proper pasteurization of milk?
Inactivation of alkaline phosphatase (phosphatase is not acceptable)
Describe lactose intolerance, its biochemical basis, and common mitigation strategies.
Lactose intolerance results from lactase deficiency, preventing lactose hydrolysis into glucose and galactose. Mitigation includes lactose-free products, fermentation, or lactase supplementation.
What are the two main proteins in milk?
Casein and whey proteins
The imitation ice cream in which milk fat is replaced with another animal or vegetable fat is known as what?
Mellorine
What is queso menonita, a frequently used cheese in Mexican restaurant, is more commonly knows as?
Queso Chihuahua
What are the two main bacterial strains used in buttermilk production?
Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris
Guernsey and Jersey cows, also known as the Channel Island breeds, produce rich, yellow milk due to a relatively high amount of what compound?
β-carotene
The cleavage of κ-casein by rennet results in two peptides. What are they called?
Para-κ-casein and the κ-casein macropeptide (also called the glycomacropeptide or just the macropeptide)
What 3 things are removed from milk during the clarification step?
Somatic cells, dirt, some microbes
Where does Emanthal cheese originate?
Switzerland
Acetaldehyde is very important for which dairy product?
Yogurt
Why is salt added in cottage cheese production?
Enhance flavor; Control microbial growth; Aid in whey drainage; Improve texture and shelf life
What is the moisture content of cheddar cheese?
36-40%
What is the required minimum weight of a gallon of frozen ice cream?
4.5 lbs
According to FDA SOI, ice cream should have what minimum percentage by weight of milk solids-not-fat (SNF)?
0.06
Classify the following dairy components as being found in the retentate or permeate following ultra filtration of milk, casein, whey proteins, micellular salts, residual fat, lactose, soluble salts, and non protein nitrogen.
Permeates: Lactose, non protein nitrogen and soluble salts Retentate: Casein, whey proteins, micellular salts, residual fat
Name the three quality grades of butter.
US Grade AA, US Grade A, US Grade B
According to the Grade A pasteurized milk ordinance recommendations of the FDA, what is the maximum bacterial plate count per ml allowed in Grade A co-mingled raw milk?
300,000 CFU/ml
Reduced fat ice cream has how much less fat than regular ice cream?
At least 25%
Name the flavor defect due to free butyric acid from the partial hydrolysis of butterfat brought about by the enzymatic activity of lipase or by certain bacterial enzymes.
Hydrolytic rancidity
Annatto is added to color cheese. What group of pigments is this colorant derived from?
Carotenoids
What is the name of milk containing between 18%-30% milk fat?
Light Cream
Milk metering systems may be affected by: a) Flow rate b) Back pressure c) Temperature d) All of the above
All of the above
What are the two underlying principles of the Babcock test?
To dissolve fat from solids-non-fat (SNF) and to separate fat from SNF by centrifugal force.
What is the name of milk containing over 36% milk fat?
Heavy Cream
What is the name of the Indian variant of clotted cream, sometimes made with Buffalo milk?
Malai
Name the 6 gradations of Gouda.
Young (4 weeks), Young Matured (8–10 weeks), Matured (16–18 weeks), Extra Matured (7–8 months), Old (10–12 months), Very Old (over 12 months)
How is condensed milk produced?
By removing about 60% of water from milk and adding sugar (for sweetened condensed milk), then canning and heat-processing it
If you centrifuge skim milk, what is the precipitate?
Casein
In the US, butter is packaged in sticks weighing how many grams?
110 g
Name 4 varieties of cheese that ripened principally by blue mold in the interior.
Blue cheese, gorgonzola, stilton, wensleydale
What microorganism causes ropiness in milk?
Alcaligenes viscolactis (also acceptable Enterobacter spp. (e.g., Enterobacter cloacae), Lactococcus lactis subsp. cremoris (some strains), Bacillus spp. (e.g., Bacillus subtilis, Bacillus polymyxa), Klebsiella spp. (e.g., Klebsiella oxytoca))
What is the name of the controversial hormone given to dairy cows to increase milk production?
Bovine Somatotropin or Bovine Growth Hormone.
What process increases the shelf life of milk by heating it to 135–150°C for a few seconds?
Ultra-high temperature (UHT) processing
What are the three usual flavors in Neapolitan ice cream, also known as Harlequin ice cream?
Strawberry, chocolate, and vanilla
What is the type of ice cream that has chocolate, vanilla, and strawberry side by side?
Neapolitan
How is cultured butter made?
The cream is treated with cultures (like yogurt), allowed to ferment and then churned into butter.
What is the primary sugar naturally found in milk, a disaccharide composed of one glucose and one galactose unit?
Lactose
What acid in milk is fermented by bacteria to provide a source of diacetyl and flavor compounds in fermented dairy products?
Lactic acid
According to FDA SOI, mayonnaise should have what minimum percentage by weight of vegetable oil?
0.65
Which of the following types of non-fat dried milk (NDM) powders has the highest solubility in pure water: A.Instant NDM, B.roller-dried NDM, C.high-heat NDM, or D.regular NDM?
A. Instant NDM
Which organism is responsible for the defect "buttons" in sweetened condensed milk?
Aspergillus repens
What cheeses are associated w/ lactococcus?
Cheddar or Mozzarella Cheese
What is the percent fat content in sour cream and half & half?
Sour cream: 18-30% Half & half: 10.5-18%
What kinds of food emulsions are butter, mayonnaise, and milk?
Butter = water in oil, Mayonnaise = oil in water, Milk = oil in water
Give an example of a mold and lactic acid bacteria fermentation product made from milk?
Kefir or Viili
Acid that is present in milk due to proteins, phosphates, carbonates, and citrates rather than from bacterial fermentation is known as what?
Apparent acidity
How much water is typically in butter?
0.2
What milk type is characterized as milk with 3.25% milk fat?
Whole Milk
What is the primary preservative in sweetened condensed milk?
Sugar
Gouda is traditionally eaten with what condiment?
Dutch mustard
What are the holes in Swiss cheese called?
Eyes
What are the approximate molecular weights of alpha-lactalbumin, beta-lactoglobulin, and bovine serum albumin (BSA)?
Alpha-lactalbumin ≈ 14,200 Da; Beta-lactoglobulin ≈ 18,400 Da; BSA ≈ 66,500 Da.
The lactose content in human milk is higher than in cow milk.
True
Which of the following is a Class III dairy product: cottage cheese, cheddar cheese, yogurt, or ice cream?
Cheddar cheese (all others class II)
Does HTST or batch (LTLT) pasteurization degrade more milk proteins and why?
Batch (LTLT) because it is held at a higher temperature for a much longer time period.
What milk product is 42 % sucrose and 12% lactose?
Condensed milk
What is the process of shaking cream or milk to make butter?
Churning
During the manufacture of ice cream, you discover that 1 liter of mix makes 2.0 liters of frozen ice cream. What's your overrun percentage?
1
What common process is used to produce emulsifiers from whey proteins?
Heating
What is a good natural source for the enzyme Xanthine Oxidase?
Milk (more specifically whey)
Name the two most abundant proteins found in milk.
Casein (Curds) and Whey
According to the National Yogurt Association, what is the minimum number of live bacteria in the final yogurt packing for it to have a 'live active culture' seal on the product?
10^8 CFU/g (100 million cultures per gram at time of manufacture)
All non-dairy milk alternatives are fortified with vitamin D and calcium to mimic the nutrients found in dairy milk.
False
According to FDA SOI, reduced fat milk should have what minimum percentage by weight of milk solids-not-fat (SNF)?
0.0825
What is the only disaccharide that mammals are able to synthesize?
Lactose
What is the name of butter made from fermented cream?
Cultured Butter
In Spanish areas, edam is sold under what name?
Queso de bola
What is the name of Dulce de Leche in Mexico made with goat's milk?
Cajeta
Name the major protein in milk.
Casein
Name the two bacteria involved in the production of yogurt using a starter culture?
Lactobacillus delbrueckii subsp. bulgaricus Streptococcus thermophilus
What is the Zeta potential of milk?
-10 to -30 mV
According to FDA SOI, butter and margarine should have what minimum percentage by weight of milk fat?
0.8
Name three advantages of pasteurization of milk used for cheese production.
Destroy pathogenic bacteria and other odor causing bacteria, removal of undesirable gases, product uniformity, higher cheese yield, better control over acid development
The following cheeses are all made with a lactic starter culture plus one additional, non-lactic microorganism. Name the additional organism for each cheese: Gorgonzola, Swiss, and Limburger.
Gorgonzola - Penicillium roqueforti, Swiss - Propionibacterium freudenreichii shermanii, Limburger - Brevibacterium linens
Cheese is formed from milk protein that coagulate at what pH?
4.6
What bacteria is added to Swiss cheese for eye formation?
Propionibacterium freudenreichii subspp. shermanii or Propionibacterium shermanii
What specific class of enzymes is thought to be responsible for the disruption of the fat globule membrane in raw milk?
Phospholipases (If lipase is given, ask for a more specific answer)
Butter is what type of emulsion?
Water in oil
What is the name of thick cream made by boiling milk than slowly cooling it in shallow pans?
Clotted Cream
Approximately 50% of the psychrotrophs isolated from raw milk belong to what bacterial genus?
Pseudomonas
What are three purposes of adding salt to milled, cheddared cheese curd?
To further draw whey out of the curd by osmosis, act as a preservative, add flavor, and cause bacterial cells to rupture, which releases enzymes for ripening
What classic method is commonly used to determine fat content in milk?
Babcock method, also Mojonnier
What is the function of the clarification process for milk?
To remove small particulate matter and suspended solids from the milk
What is the cause of cardboard flavor in milk?
Oxidative rancidity
Give the names of two major breeds of dairy cattle.
Holstein, Jersey, Brown Swiss, Shorthorn, Ayrshire, and Guernsey
Evaporated milk is made by evaporating what % of milk?
0.6
Which state leads the nation in Swiss cheese production?
Ohio
What is the starter culture used in the manufacture of cultured buttermilk?
A mixed culture of Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, and optionally Leuconostoc mesenteroides subsp. cremoris (for flavor development)
Benzoyl peroxide is sometimes used during the manufacture of bleu cheese to bleach the milk to make the cheese whiter. Which of the fat-soluble vitamins will suffer the most loss of activity because of this practice?
Vitamin A
What vitamin is synthesized by lactic acid bacteria during yogurt fermentation?
Vitamin B₁₂ (in small amounts, strain-dependent)
What is the primary function of milk pasteurization?
Kill pathogens
What is the primary function of carrageenan in dairy systems?
Protein stabilization and texture enhancement
What is HTST method in dairy technology and what are the requirements?
High Temperature Short Time is a pasteurization process for milk: 72 degrees C for 15 seconds
What is the primary function of Leuconostoc cremoris in sour cream production?
Flavor production (diacetyl)
State the equation for % overrun of ice cream.
(Volume of ice cream - volume of mix)/volume of mix x 100
Is Bovine Growth Hormone (BGH) a food additive and does it need to be labeled?
No. It is not added to the food. It is injected into the cow and she becomes more efficient in milk production. Some producers choose to label, but no special labeling is required by law.
According to FDA SOI, whole milk should have what minimum percentage by weight of milk fat?
0.0325
Differentiate between evaporated and sweetened condensed milk.
Evaporated milk is made by evaporating water from whole milk under a vacuum. It may be homogenized and/or fortified with vitamin D and then sterilized in cans. By contrast, sweetened condensed milk is canned without sterilization with 18% sucrose acting as a preservative.
What percentage does lactose take up in whole milk?
0.048
What is the cause of the stale flavor in milk?
Oxidation
What milk type is characterized as milk with less than 0.5% milk fat?
Skim Milk
In cheese production, why is rennet added after pH has been slightly reduced by the starter cultures?
Rennet is added after a slight drop in pH because acidification destabilizes casein micelles, especially kappa-casein, making them more susceptible to enzymatic coagulation by rennet. This enhances curd formation and yields a firmer coagulum.
What compound in cultured butter increases it flavor?
Diacetyl
What is the fat content of half & half, light cream, light whipping cream, and heavy cream?
Half and half: 10-18% fat Light cream: 18-30% fat Light whipping cream: 30-36% fat Heavy cream - 36% fat or more.
Traditionally, Halumi cheese is made with what kind of milk?
Mixture of sheep’s and goat’s milk
What is the primary purpose of using the enzyme rennet (or chymosin) in cheesemaking?
To coagulate the casein protein in milk (to form a curd)
Casein micelles have what type of core and outer surface: hydrophobic or hydrophilic?
The core is hydrophobic and outer surface is hydrophilic
Explain the difference between homogenization and pasteurization in milk processing.
Homogenization mechanically breaks down fat globules to prevent creaming; pasteurization uses heat to destroy pathogens and extend shelf life.
Which protein is the most hydrophobic in casein?
Beta-Casein
What two food colorants may be added to butter?
Carotene, Annatto
Which protein is 80% of milk protein?
Casein
What is the name of the machine that packs butter?
Butter Printers
What famous football coach said, "I have never had an outstanding successful athlete who was not a hard milk drinker"?
Vince Lombardi
Name the volatile fatty acids in milk and state the number of carbons in each.
Butyric (C4) Caproic (C6) Caprylic (C8) Capric (C10) Lauric (C12)
Why is the measurement of phosphatase enzyme used to assess the adequacy of milk pasteurization?
The alkaline phosphatase enzyme is more heat-resistant than most pathogens, so its inactivation indicates that pasteurization has been sufficient to destroy harmful microbes.
This cultured dairy product is very popular in the Middle East, Eastern Europe, and Central Asia and accounts for as much as 70% of all cultured dairy products consumed worldwide.
Kefir
What starting ingredient is used to make buttermilk?
Cultured buttermilk: Made by fermenting low-fat or skim milk with lactic acid bacteria. Traditional buttermilk: The liquid left over after churning butter from cream.
Name the enzyme that is used to precipitate casein from fluid milk in order to produce cheese.
Rennin (or more properly Chymosin)
What device is used to determine the specific gravity of milk?
Lactometer
What is the most hydrophilic protein in casein micelle?
K-casein
What process in cheesemaking turns lactose to lactic acid?
Coagulation
What hydrocolloid is primarily used as a stabilizer in chocolate milk and ice cream?
Carrageenan
What is the name of the traditional Dutch cheese?
Gouda or Edam
Degradation of what vitamin is responsible for oxidized defect in milk?
Riboflavin
The specific class of protein that is acted upon by rennin to bring about clotting of milk casein is called what?
κ-casein
Which protein in milk is not secreted by mammary glands?
Bovine serum albumin
What is the term for the increase in volume caused by whipping air into ice cream during freezing?
Overrun
What happens if whipped cream is whipped too far?
The fat begins to turn into butter/ cream separates into butter and buttercream
What is the difference between gelato and ice cream in terms of sugar and fat content, and overrun?
Gelato is higher in sugar, lower in overrun and fat
What fermented beverage is made from mare's milk?
koumis
For a dairy cow to make 1 liter of milk, how many liters of blood must circulate through the udder?
400 liters
What are the two most common grades of milk in the United States?
Grade A (fluid milk) and Grade B (used primarily for cheese and other processed products)
What are two major buffering components of milk?
Casein protein and phosphates
Name the piece of milk processing equipment used to remove sediment originating from the cow's udder and some bacteria?
Clarifier
What is the country of origin of Feta cheese?
Greece
What is the name of this Italian cheese that contains live maggots?
Casu Marzu
10 pound of cheese corresponds to how much whey?
90 pounds of whey
What are the time-temperature combinations used in the following thermal processes for the pasteurization of milk: Batch/LTLT, HTST, and UHT?
Batch/LTLT: 63°C (145 °F) for 30 minutes HTST: 72°C (161 °F) for 15-20 seconds UHT: 135-150°C (275-302°F) for 2-5 seconds
What process in yogurt manufacturing shortens the incubation time because the cultures are anaerobic and grow faster?
Deaeration
What is the name of sugar and milk heated over several hours, causing caramelization?
Dulce de Leche
What enzyme is traditionally used to coagulate milk during cheese production?
Rennet (chymosin).
According to FDA SOI, ice cream should have what minimum percentage by weight of total milk solids?
0.2
What is the name of gouda produced in the traditional manner, using unpasteurized milk?
Boererenkaas
Which generally displaces milk proteins from the fat surface during the ice cream aging period? A. air cells B. ice crystals C. stabilizers D. emulsifiers
D. emulsifiers
Which heat-induced interaction causes age gelation in UHT milk?
β-lactoglobulin–κ-casein interactions.
What is the major fatty acid in butter?
Palmitic acid.
Which enzyme is used in cheese making to specifically cleave κ-casein?
Chymosin
What is done to Gouda cheese to give its distinctive taste?
Brine
What flavor attribute does milk that has been UHT processed typically have?
Cooked flavor
What is the function of homogenization in milk production?
To reduce fat droplet size so cream separation does not occur
Give the genus and species names of the microorganism responsible for the formation of eyes in Emmental cheese.
Propionibacterium freudenreichii subspp. shermanii or Propionibacterium shermanii
List 2 functions of calcium chloride in cheese making.
Reduces clotting time, increases curd firmness, and increases whey exudation
According to FDA SOI, skim milk should have what minimum percentage by weight of milk solids-not-fat (SNF)?
0.0825
What is the microaerophilic bacteria used in dairy production?
Lactobacillus sp.
Where does cheddar cheese originate from?
England
What is the most prudent and practical means of processing milk in third world countries?
Boiling
β-D-galactosidase is added to dairy products for what 3 reasons?
Prevents sandiness in ice cream; makes ice cream more scoopable, and enables people with lactose intolerance to consume dairy
What is the percent fat in the following ice creams: Standard, Premium, Superpremium?
Standard ~10, Premium ~15, Superpremium ~18
What is the shelf life of UHT processed milk?
Six to nine months
What is the name of butter made from fresh cream?
Sweet cream butter
What is BGH?
Bovine Growth Hormone: regulates growth and milk production
What is the name of butter that has dimensions of 4.75, 1.25, 1.25 inches?
Elgin/ butter stick
What causes fat destabilization in ice cream?
Partial coalescence of fat globules.
What general class of enzymes is used to coagulate the casein protein in milk to form the curds for cheesemaking?
Rennet (or Chymosin, or a microbial coagulant)
What proteolytic enzyme is used in cheese production?
Chymosin or rennin
Provide five key concepts in the definition of milk.
The lacteal secretion, practically free of colostrum, from the milking of one or more healthy cows, with not less than 8.25% solids-non-fat, and not less than 3.25% milk fat
What are the target microorganisms for milk pasteurization?
Mycobacterium tuberculosis and Coxiella burnetti
What will occur in a sample of milk at 20 degrees C when the pH is lowered to 4.6?
Curdling or coagu;ation
What is the main sugar found in milk?
Lactose
What are the three types of clotting in cheese production?
Acid, heat coagulations of whey proteins, and enzymatic.
The principle lipid component in milk is the class called which of the following: A) steroids B) phospholipids C) triacylglycerides
C) triacylglycerides
What carbohydrate is fermented during yogurt production?
Lactose.
Give three functionalities of caseinates.
High solubility, low viscosity, clean flavor, emulsification, high fat and water-binding, freeze-thaw stability, calcium and protein fortification
What are two main lactic acid bacteria used in making commercial yogurt and are usually added at what ratio?
Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus in a 1:1 ratio
What is the name of the product made from fermented mare's milk?
Koumis
Give the country of origin of the following cheeses: Feta, Monterey Jack, Primost, Gouda, Roquefort, Stilton, Gorgonzola, Fourme d'Ambert, Cabrales, Camembert, Limburger, Danablu
Feta: Greece; Monterey Jack: USA; Primost: Norway; Gouda: Netherlands, Roquefort: France, Stilton: UK, Gorgonzola: Italy, Fourme d'Ambert: France, Cabrales: Spain, Camembert: France, Limburger: Belgium, Danablu: Denmark
What fat-soluble vitamin is lost when milk is irradiated?
Vitamin A
In cheese making, when rennet comes into contact with milk, the milk curdles into 2 components. Name the 2 components.
Curd and whey
To prevent the reoccurrence of staphylococcal food poisonings through spray-dried nonfat milk, the USDA incorporated DMCC levels as quality factor in the U.S. Standards for Grades of Nonfat Dry Milk. What does the acronym DMCC stand for?
Direct Microscopic Clump Count
What enzyme is added to milk to form curds in cheese production?
Rennet (contains chymosin)
How much sucrose and lactose are in condensed milk?
40-45% sucrose and 10-12% lactose
What type of whey is produced during the manufacture of Swiss cheese?
Sweet whey
Colby cheese originated from _____
Wisconsin, US
Most of us know Emmenthal cheese more commonly by what name?
Swiss cheese
What are the four best-known varieties of blue-veined cheeses?
Blue cheese, Stilton, Gorgonzola, Roquefort
What are the two steps in rennet coagulation of milk?
Enzymatic cleavage of K-casein, aggregation and gelation of caseins.
What Finnish product is made by fermenting milk with the mold Geotrichum candidum and bacteria Lactococcus lactis subsp. lactis biovar diacetylactis?
Viili
What is 'overrun' and what product does it relate to?
Overrun measures the amount of air in ice cream. The volume is increased during the freezing process, but the mass remains the same
Milk plasma, or milk without fat, is another name for what?
Skim milk
Define the ingredient MSNF used in commercial ice cream.
Milk solids not fat - the dairy solids other than fat - 37% protein, 56% lactose, and 8% minerals
Heavy whipping cream contains what percent fat?
At least 36% milk fat by weight (CFR Title 21, Part 131, Subpart B, Milk and Cream)
What is the PER value for milk casein?
2.5
Who is credited with being the first to successfully pasteurize milk?
Franz von Soxhlet in 1886
What is 2-10 milk?
Milk containing 2% fat and 10% milk solids nonfat
What is the name of the solid mass separated from whey during cheese-making?
Curd.
Rank these cheeses from lowest moisture content to highest moisture content. Neufchatel, Romano, Gruyere, Munster, edam
Romano (Hardest, approx 32%), Edam and Gruyere (approx 40-42%), Munster (approx 45%), and Neufchatel (Softest, approx 50-65%)
Edam was popuplar from the 14th century to 18th century due to its resistence of what quality?
Spoilage
What is the name of butter with all water and milk solids removed?
Clarified Butter/ Ghee
How is volatile acidity measured?
Steam distillation and titration
The standard identity for yogurt in the US requires the presence of what 2 organisms?
Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus
What is the typical fat percentage of whole milk in the U.S.?
Approximately 3.25%
Define "Apparent Acidity" in milk.
Acid in milk as from cow due to proteins, phosphates, carbonates, and citrates
What amino acid found in crystals in aged cheese is associated with headaches?
Tyramine (produced by the breakdown of the amino acid tyrosine)
What is the name of clarified butter that is simmered?
Ghee
According to FDA SOI, skim milk should have what percentage by weight of milk fats?
less than 0.5%
What is the scientific name for the enzyme lacking in individuals with lactose intolerance?
β-galactosidase (Lactase not accepted)
What sugar is naturally present in milk?
Lactose.
What milk protein is present in cheese?
Caesin
What is the clotted protein formed when fresh milk is treated with rennet?
Curd
What is considered world's most expensive cheese?
Pule cheese
What is the major protein of milk? What is the standard protein for protein digestibility test? What protein is universally considered to be nutritionally complete?
Casein
Clotted Cream is essential to what beverage?
Cream Tea
Name the ice cream-like product containing at least 1.4% egg yolk solids, also known as French ice cream?
Frozen custard
Clarified butter fat after water is removed is called?
Butter oil
What is the country of origin of Monterey Jack cheese?
USA
What are the highest bacterial counts allowed in grade A pasteurized milk?
SPC = 20,000/ml; coliforms = 10/ml; raw milk = 100,000 cfu/ml
What is the source of the milk used in making Roquefort cheese?
Ewe/female sheep
What is the concentration of β-lactoglobulin in human milk?
0. There is none
To what temperature must milk be cooled within 2 hours of milking?
7°C (45°F)
What is the name of milk mildly caramelized by simmering in low heat?
Baked Milk
Which milk product is concentrated to 2.25 times the solids of normal milk and then sterilized in cans in continuous pressure retorts at 245 °F or 118.3 °C for 15 minutes?
Evaporated milk
The Delvo test is a commonly used rapid method for detection of antibiotic residue in milk. What organism is used in this test?
Bacillus stearothermophilus
What is the function of heterofermentative lactic acid bacteria in fermented dairy foods?
Production of flavor compounds (homofermenters primarily increase acidity)
Name the two molds used in blue cheese production.
Penicillium roqueforti, Penicillium glaucum
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