14. Dairy Products Flashcards
What gives skim milk a slight bluish tint?
Riboflavin;
The lactic acid in cheese is made from what compound?
Lactose;
What are the consequences when milk is overheated?
Denaturation/coagulation and sulfur release;
Give the names of two major breeds of dairy cattle.
Holstein/Jersey/Brown Swiss/Guernsey;
Where are lipovitellins and livetins found?
Plasma proteins of egg yolk;
In cheese production why is rennet added after pH has been slightly reduced by the starter cultures?
The activity of clotting enzymes (rennet) is higher in acid media;
Which cheese is made from the by-product of cheese production?
Ricotta Cheese;
Skim milk has a bluish tint due to the scattering of light by what component?
Casein micelles;
What are the major components of bovine milk and what are their approximate percentages?
Water-87% / Lactose- 4-5% / Fat- 4% / Protein-3.5% / Minerals- 0.7%;
What is the monosaccharide in milk?
Galatose and glucose;
What are two ways milk is dried into powdered form?
Spray drying and roller drying.;
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 the fat-soluble pigment.;
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.
Lactose is commonly isolated from whey. Name two ways this can be accomplished.
Crystallization or Nanofiltration;
What milk protein is responsible for iron binding and enhanced iron absorption into the body?
Lactoferrin;
Whey protein concentrate (WPC) is produced with three different protein percentages. What are they?
34% - 50% - 80%;
What is the major protein group in milk?
Casein;
What is the name of the controversial hormone given to dairy cows to increase milk production?
Bovine Somatotropin or Bovine Growth Hormone;
What does MFGM stand for?
Milk Fat Globule Membrane;
What are the approximate molecular weights of alpha-lactalbumin/beta-lactoglobulin/bovine serum albumin (BSA)?
Alpha-lactalbumin= app. 14200 Da / Beta-lactoglobulin= app. 18400 Da / BSA= app. 69000 Da;
What hydrocolloid’s largest use is a stabilizer in chocolate milk and ice cream?
Carrageenan;
Which milk product is concentrated to 2.25 times the solids of normal milk then sterilized in cans in continuous pressure retorts at 245F for 15 minutes?
Evaporated Milk;
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);
Name the two principal whey proteins.
Beta-lactoglobulin and alpha-lactalbumin;
What is direct acid set cottage cheese?
Cottage cheese made with food grade organic acids rather than bacteria starter cultures.;
Define percent overrun in ice cream.
The volume of frozen/finished ice cream in excess of the volume of the liquid mix.;
The compound responsible for the characteristic buttery flavor of fermented dairy foods is what?
Diacetyl;
What is the legal percentage of butter fat to be classified as whole milk?
0.0325;
If whey proteins are heated what three changes can be observed?
Coagulation/Denaturation/Maillard Browning;
Acid that is present in milk due to proteins-phosphates-carbonates-citrates rather than from bacterial fermentation is known as what?
Apparent Acidity;
What is rennin?
Proteolytic enzyme from the stomach of suckling calves.;
Cow’s milk normally contains how much lactose?
5% by weight;
Whey normally contains how much lactose?
5% by weight;
What is the function of gelatin in an ice cream mix?
Stabilization-it retards ice crystal formation during frozen storage of the finished product.;
What is butter without salt called?
Sweet Butter;
What compound is commonly used to color cheese?
Annatto Extract;
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;
What is cheddaring?
The process where matted cheese curd is cut into blocks stacked and drained of whey.;
What is the most prudent and practical means of processing milk in third world countries?
Ultra-high temperature (UHT);
What makes milk white?
The casein micelles which scatter light.;
Name the common flavor defect found in milk exposed to light?
Light oxidized flavor;
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.;
Cheddar is America’s favorite cheese. What is second?
Mozzarella;
Which cows produce the most milk?A) Jerseys B) Guernseys C) Holsteins
C. Holsteins;
Name a good natural source for the enzyme Xanthine Oxidase.
Milk;
Which cows produce milk with higher fat content: Hosteins or Jerseys?
Jerseys;
What kind of milk is Roquefort cheese made from?
Sheep’s Milk;
What proteolytic enzyme is used in cheese production?
Chymosin or Rennin;
What is the amino acid that is most responsible for off-flavor development in milk?
Methionine;
Name the four major categories of cheese.
Soft unripened - Soft ripened - Semisoft ripened - Hard.;
What are the two steps in rennet coagulation of milk?
Enzymatic cleavage of K-Casein + aggregation and gelation of caseins.;
The lactose content in human milk is higher than in cow milk?
TRUE;
On a weight percent basis what are the two predominant fatty acids in cow’s milk?
Palmitic (24-26%) and Oleic (34-38%)
