IIA. Milk and Dairy Growth Media

Question 1

• utilized by microorganisms but
does not support significant growth

Answer 1

citrate

Question 2

• allows growth of microorganisms

Answer 2

glucose

Question 3

• spoilage microorganisms oxidize lactose to __________

Answer 3

lactobionic acid

Question 4

• present in the form of highly hydrated micelles and is susceptible to
proteolysis

Answer 4

casein

Question 5

• ß-lactoglobulin, - lactalbumin, serum albumin, and immunoglobulins

Answer 5

whey proteins

Question 6

• microbial inhibitors in raw milk

Answer 6

lactoferrin and lactoperoxidase

Question 7

• a glycoprotein that act as an
antimicrobial agent by binding iron
which inhibits psychrotrophic aerobes

Answer 7

lactoferrin

Question 8

• catalyzes the oxidation of thiocyanate and reduction of hydrogen peroxide

Answer 8

lactoperoxidase

Question 9

• an acidified milk that provides
nutrient-rich low-pH environment

Answer 9

yogurt

Question 10

• less acidified than yogurt but
have added salt and less water resulting in lower water activity

Answer 10

cheese

Question 11

• do not have sufficiently low water activity to inhibit and must be canned or refrigerated for preservation

Answer 11

liquid milk concentrates

Question 12

• have low water activity to inhibit microbial growth

Answer 12

milk-derived powders

Question 13

• a water-in-oil emulsion that has a water content of 6-8% sufficient to
inhibit gram-negative spoilage microorganisms

Answer 13

butter

Question 14

• made from acidified cream and relies on low pH an

Answer 14

unsalted butter

Question 15

AlBacFlavMicro
StapEntPseuNeiss

Answer 15

Alcaligenes, Bacillus, Flavobacterium, Micrococcus
Staphylococcus, Enterobacteriaceaeeae, Pseudomonadaceae, Neisseeiaceae