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Flashcards in Key words Deck (36):
1

Instrinsic Factors

Characteristic of the food itself.
Moisture, acidity, pH, nutrition, biological strcuture, redox potential and antimicrobial properties

2

Extrinsic Factors

Environment surronding the food.
Temp, humidity and oxygen

3

Water activity

Ratio of water vapour pressure of the food substrate to the vapour pressure of pure water at the same temp

4

Relative humidity

measure of water activity of the gas phase

5

Neurotoxin

Poison that acts on the nervous system

6

hydrogenation

Conversion of some or all of the unsaturated carbon-carbon bonds to the saturated form of hydrogen

7

Food systems

Two systems: intact edible tissue and food dispersions.
Intact = systems of biological cells interconnected by adhesive polymer systems and/or membranes. Examples - fruits
Food dispersions - have a continous and dispered phase

8

Emulsifer

Substance added to stabilise an emulsion.
Lecithin

9

Plant hydrocolloids

Vegatable gums.
Bind and immobillise water to give viscous solutions.
Gum arabic, pectin and guar gum

10

Sols

S/L colloid system.
In between a true solution and a suspension

11

gels

Formed when macromolecules interact to forma 3D network in which water is trapped

12

Mesophilles

Extrinsic organism.
Optimum 35-45C

13

Psychrophilles

Extrinisic organism.
Grow well at 0C
Optimum = 15C

14

Thermophilles

Extrinsic organism
OPtimum 45-65

15

Thermooduric

microorgansism capable of surviving high temps

16

Anaerobic

Don't require oxygen

17

Aerobes

Requires oxygen

18

Obligate aerobes

require oxygen and have a high redox potential

19

Oligate anaerobe

Doesnt require oxygen and has a low redox potential

20

Facultative anaerobe

Can grow with or without oxygen

21

Micro-aerophillic

Prefer reduced oxygen environment

22

Osmophiles

Bacteria that spoils foods of high sugar content

23

Halophiles

Bacteria that spoils food of high salt content

24

Xerophiles

Mould that spoils dried food

25

redox potential

Result of transfer of electrons between atoms or molecules

26

Cis fatty acids

Hydrocarbon chains are on the same side of the carbon-carbon bond

27

Trans fatty acids

Hydrocarbons are on the geometrically opposite sides of the double binds

28

Pathogencity

Ability to cause diasease by overcoming the defences of the host

29

Virulence

Degree or extent of pathogencity

30

Virulence factors

traits that allow or enhance the microorgansims ability to cause disease

31

Pili

Used to bind host cells in adherance

32

Endotoxin

Part of outer cell wall.
Liberated when the bacteria dies and the cell wall breaks apart

33

Exotoxin

produced inside gram positive bacteria as part of their growth and metabolism
Then released into surronding medium

34

Zwitterion

solid crystalline state of acidic and basic groups in a protein

35

Chlorophylls

Food processibg ior storage causing some deterioration of pigements

36

ICMSF

International commision on microbiologiccal specifications for foods