Extrinsic Factors chpter 4 Flashcards Preview

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Flashcards in Extrinsic Factors chpter 4 Deck (20):
1

What is the difference between extrinsic and intrinsic factors?

Extrinsic factors are factors that can be controlled without changing the food. While intrinsic factors often change the food.

2

What are the two main extrinsic factors?

Temperature and gaseous environment

3

What is the danger zone?

4.4-60C Most microorganisms grow in this range.

4

Minimum growth Temp?

Lowest temp that an organism will grow. SLow growth to no growth. Just cell maintenance.

5

Optimum growth temp?

Temp at which growing fastest.

6

Maximum growth temp?

Temp in whcih cells cannot make any more enzymes, start to die.

7

Kill all viable cells at what temp?

80C

8

Kill all cells at what temp?

Using pressure as well. 100C kills all growth.
at 121C SPORES KILLED.

9

What microorganisms can be survive below 4C?

Listeria, C. botolinum, and yersina entercolitica

Parasites (destroy by below -20C). Viruses are fine.

10

What is used to store bacteria?

Glycerol, it prevents crystalization so we cna store bacteria.

11

Psychrophile

<20C cold lovers. Vibrio

12

Psychrotrophs

30C found in fridge.

13

Mesophiles

>35C potimal. 7-10C min and 40-60C max

14

thermodurics

Endospore forming survives but do not grow at temp> 60C

15

thermophiles

optimal > 45C SPORES or up till 80C

16

What is the difference between endospores and fungi spores

Endospores from bacteria are heat resistant to heat, drying, and disinfecting chemicals.
While fungi spores are NOT heat resistant.

17

Gaseous environment:
Describe what bacteria is found in aerobic conditions

Gram -, non-spore forming, rods (speudomonaus), oxidateive and breakdown of fats and proteins. odor found at 10^6- 10^7 CFU/g of meat. Gives off CO2.

18

Anarobic conditions

gram +, spore forming, LAB, fermetnave and converts sugar to LA and acetic acid. spoilage is detectable after max population reached.
Low redox potentials. Souring occurs.

19

What is a facultative anarobe

It can survive in both oxygen and no oxygen conditions.

20

aerotolerant anarobe

Survives in the presence of oxygen but still does anarobic metabolism.