chpt 16 definitions

Question 1

perishable foods

Answer 1

food that readily supports survival and growth of microorganisms such as fresh lettuce strawberries and meat

Question 2

semi-perishable foods

Answer 2

food that is semi-dry, making it low in available water, and that does not easily support microbial growth

Question 3

non-perishable foods

Answer 3

food that does not support microbial growth due to lack of available water

Question 4

intrinsic factors

Answer 4

a characteristic inherent quality of the food, such as water and salt content

Question 5

extrinsic factors

Answer 5

a characteristic of the storage environment of the food, such as temperature and humidity

Question 6

enterotoxins

Answer 6

microbial secreted toxin that acts on the gut and causes or contributes to the intestinal symptoms in an affected individual

Question 7

freeze-drying (lyophilization)

Answer 7

process for preserving food, whereby food is frozen and then dried under a vacuum, allowing removal of water by sublimation

Question 8

refrigeration

Answer 8

food preservation done at cold temperature, usually 1-4degC

Question 9

canning

Answer 9

high heat process for food preservation where food is heated to 100 deg C or above for an extended period of time, followed by sealing in a sterilized can or jar

Question 10

pasteurization

Answer 10

any technique using mild heating, irradiation, or high pressure to destroy spoilage or pathogenic microorganisms without cooking the food product

Question 11

flash-heating pasteurization

Answer 11

pasteurization method that heats a small volume of liquid to a very high temp (at least 72degC) for a short period of time (15 sec or less); includes high temp short time and ultrahigh temp processes (HTST and UHT)

Question 12

low-temperature hold (LTH)

Answer 12

pasteurization method that heats a large volume o liquid to a low temp for a long period of time

Question 13

botulism

Answer 13

foodborne intoxication resulting in flaccid paralysis that occurs when botulinum toxin produced by clostridium botulinum is ingested

Question 14

bacteriocins

Answer 14

antimicrobial peptide produced by one strain of bacteria and that is harmful to another strain within the same family

Question 15

pickling

Answer 15

acidification of food for storage by adding dilute acetic acid (vinegar) or allowing lactic or acetic acid production to occur naturally through microbial fermentation

Question 16

irradiation

Answer 16

exposure to radiation, commonly used to reduce microbial contamination of food and surfaces

Question 17

non-ionization radiation

Answer 17

radiation of wavelength longer than 240nm that does not possess sufficient energy to produce ions in solution; non-ionizating UV radiation of wavelength 240-280 can damage DNA

Question 18

ultraviolet radiation

Answer 18

light with a wavelength range of 100-400nm

Question 19

ionizing radiation

Answer 19

high energy penetration radiation in the form of UV light, Xray, or gamma rays; commonly used for pasteurization or sterilization of foods

Question 20

modified atmosphere packaging (MAP)

Answer 20

packaging technology that substitutes the atmospheric air inside the package with a gas mixture designed to extend the shelf life of a food product

Question 21

Hurdle technology

Answer 21

the use of multiple constraints of hurdles to control the growth of pathogens and spoilage microorganisms in foods; targeted microorganisms must overcome each hurdle in order to proliferate

Question 22

starter cultures

Answer 22

microbial inoculum used in the production of cultured dairy products, fruits, or grains

Question 23

foodborne intoxication

Answer 23

illness caused by ingestion of food containing microbial exotoxings

Question 24

foodborne infection

Answer 24

disease caused by the ingestion of live pathogens that ctively multiply within the body

Question 25

potable

Answer 25

water suitable for drinking and judged to be free from intestinal bacteria and pathogens

Question 26

wastewater/sewage

Answer 26

water carrying soluble or solid wastes originating from human activities, including farming, industry and domestic waters

Question 27

eutrophication

Answer 27

increase in the concentration of nutrients such as nitrogen and phosphate compounds in an aquatic ecosystem, leading to rapid growth in autotroph populations, particularly algea

Question 28

primary treatment

Answer 28

physical removal of particulate matter by sedimentation to form sludge and oils by skimming

Question 29

primary sludge

Answer 29

sludge that is a product of primary treatment of wastewater; consisting of large particulate matter

Question 30

secondary treatment

Answer 30

wastewater treatment procedure following primary treatment that makes use of microbial activities to degrade the organic content of the sewage; examples include use of a trickling filter or activated sludge treatment

Question 31

mineralization

Answer 31

the end result of decomposition of organic material, which leaves behind inorganic mineral components

Question 32

trickling filter

Answer 32

a form of secondary treatment for wastewater effluent that uses a filter bed of solid material, which supports a microbial biofilm community; effluent is distributed across the bed surface by a rotary spray bom

Question 33

activated sludge

Answer 33

secondary wastewater treatment using the perfusion of oxygen through accumulated flocs to maintain aerobic digestion by microorganisms

Question 34

tertiary treatment

Answer 34

wastewater treatment protocol sometimes used following secondary treatment, involving additional biological or physiochemical procedures to further remove organic or inorganic material prior to disinfection and release to a natural water source

Question 35

chlorination

Answer 35

disinfection process for water treatment that uses the addition of a hypochlorite solution, such as bleach, or percolation of chlorine gas through water to produce hypochlorous acid (HOCl), a strong oxidizing agent

Question 36

effluent

Answer 36

outflow water that is discharged to another treatment tank or released to a water supply

Question 37

flocs

Answer 37

clumps of biomass consisting of adsorbed material and microorganisms

Question 38

exopolysaccharide

Answer 38

high-moleculcar-weight polymer composed of various sugars that is secreted by microbes into the surrounding medium and aids in the formation of a biofilm

Question 39

secondary sludge

Answer 39

sludge that is a product of secondary treatment of wastewater, consisting of accumulated floc material

Question 40

anaerobic sludge digester

Answer 40

large anoxic bioreactor operating in a semi-continuous mode that allows anaerobic digestion of remaining biowaste sludge following primary and secondary wastewater treatment

Question 41

biochemical oxygen demand (BOD)

Answer 41

measure of the amount of dissolved oxygen required by microorganisms to decompose the organic matter in a sewage or water sample

Question 42

persistent organic pollutants (POP)

Answer 42

chemicals such as synthetic drugs and pesticides that are resistant to degradation and can be present in low concentrations in effluent waters; POPs tend to bioaccumulate in animal tissues

Question 43

biosolid

Answer 43

composted or treated sludge that is suitable for use as soil conditioner in horticulture and agriculture

Question 44

fecal coliforms

Answer 44

group of coliform bacteria indigenous to the intestinal tract of humans and animals

Question 45

indicator organisms

Answer 45

microbe, particularly fecal coliform bacteria, whose presence in a water sample indicates fecal matter is present and by association, potential intestinal pathogens

Question 46

most probable number

Answer 46

presumptive test used to estimate fecal coliform bacteria numbers in a water samper