Key words

Question 1

Instrinsic Factors

Answer 1

Characteristic of the food itself.

Moisture, acidity, pH, nutrition, biological strcuture, redox potential and antimicrobial properties

Question 2

Extrinsic Factors

Answer 2

Environment surronding the food.

Temp, humidity and oxygen

Question 3

Water activity

Answer 3

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

Question 4

Relative humidity

Answer 4

measure of water activity of the gas phase

Question 5

Neurotoxin

Answer 5

Poison that acts on the nervous system

Question 6

hydrogenation

Answer 6

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

Question 7

Food systems

Answer 7

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

Question 8

Emulsifer

Answer 8

Substance added to stabilise an emulsion.

Lecithin

Question 9

Plant hydrocolloids

Answer 9

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

Question 10

Sols

Answer 10

S/L colloid system.

In between a true solution and a suspension

Question 11

gels

Answer 11

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

Question 12

Mesophilles

Answer 12

Extrinsic organism.

Optimum 35-45C

Question 13

Psychrophilles

Answer 13

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

Question 14

Thermophilles

Answer 14

Extrinsic organism

OPtimum 45-65

Question 15

Thermooduric

Answer 15

microorgansism capable of surviving high temps

Question 16

Anaerobic

Answer 16

Don’t require oxygen

Question 17

Aerobes

Answer 17

Requires oxygen

Question 18

Obligate aerobes

Answer 18

require oxygen and have a high redox potential

Question 19

Oligate anaerobe

Answer 19

Doesnt require oxygen and has a low redox potential

Question 20

Facultative anaerobe

Answer 20

Can grow with or without oxygen

Question 21

Micro-aerophillic

Answer 21

Prefer reduced oxygen environment

Question 22

Osmophiles

Answer 22

Bacteria that spoils foods of high sugar content

Question 23

Halophiles

Answer 23

Bacteria that spoils food of high salt content

Question 24

Xerophiles

Answer 24

Mould that spoils dried food

Question 25

redox potential

Answer 25

Result of transfer of electrons between atoms or molecules

Question 26

Cis fatty acids

Answer 26

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

Question 27

Trans fatty acids

Answer 27

Hydrocarbons are on the geometrically opposite sides of the double binds

Question 28

Pathogencity

Answer 28

Ability to cause diasease by overcoming the defences of the host

Question 29

Virulence

Answer 29

Degree or extent of pathogencity

Question 30

Virulence factors

Answer 30

traits that allow or enhance the microorgansims ability to cause disease

Question 31

Pili

Answer 31

Used to bind host cells in adherance

Question 32

Endotoxin

Answer 32

Part of outer cell wall.

Liberated when the bacteria dies and the cell wall breaks apart

Question 33

Exotoxin

Answer 33

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

Question 34

Zwitterion

Answer 34

solid crystalline state of acidic and basic groups in a protein

Question 35

Chlorophylls

Answer 35

Food processibg ior storage causing some deterioration of pigements

Question 36

ICMSF

Answer 36

International commision on microbiologiccal specifications for foods