chpt 16 definitions Flashcards
perishable foods
food that readily supports survival and growth of microorganisms such as fresh lettuce strawberries and meat
semi-perishable foods
food that is semi-dry, making it low in available water, and that does not easily support microbial growth
non-perishable foods
food that does not support microbial growth due to lack of available water
intrinsic factors
a characteristic inherent quality of the food, such as water and salt content
extrinsic factors
a characteristic of the storage environment of the food, such as temperature and humidity
enterotoxins
microbial secreted toxin that acts on the gut and causes or contributes to the intestinal symptoms in an affected individual
freeze-drying (lyophilization)
process for preserving food, whereby food is frozen and then dried under a vacuum, allowing removal of water by sublimation
refrigeration
food preservation done at cold temperature, usually 1-4degC
canning
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
pasteurization
any technique using mild heating, irradiation, or high pressure to destroy spoilage or pathogenic microorganisms without cooking the food product
flash-heating pasteurization
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)
low-temperature hold (LTH)
pasteurization method that heats a large volume o liquid to a low temp for a long period of time
botulism
foodborne intoxication resulting in flaccid paralysis that occurs when botulinum toxin produced by clostridium botulinum is ingested
bacteriocins
antimicrobial peptide produced by one strain of bacteria and that is harmful to another strain within the same family
pickling
acidification of food for storage by adding dilute acetic acid (vinegar) or allowing lactic or acetic acid production to occur naturally through microbial fermentation
irradiation
exposure to radiation, commonly used to reduce microbial contamination of food and surfaces
non-ionization radiation
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
ultraviolet radiation
light with a wavelength range of 100-400nm
ionizing radiation
high energy penetration radiation in the form of UV light, Xray, or gamma rays; commonly used for pasteurization or sterilization of foods
modified atmosphere packaging (MAP)
packaging technology that substitutes the atmospheric air inside the package with a gas mixture designed to extend the shelf life of a food product
Hurdle technology
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
starter cultures
microbial inoculum used in the production of cultured dairy products, fruits, or grains
foodborne intoxication
illness caused by ingestion of food containing microbial exotoxings
foodborne infection
disease caused by the ingestion of live pathogens that ctively multiply within the body
potable
water suitable for drinking and judged to be free from intestinal bacteria and pathogens
wastewater/sewage
water carrying soluble or solid wastes originating from human activities, including farming, industry and domestic waters
eutrophication
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
primary treatment
physical removal of particulate matter by sedimentation to form sludge and oils by skimming
primary sludge
sludge that is a product of primary treatment of wastewater; consisting of large particulate matter
secondary treatment
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
mineralization
the end result of decomposition of organic material, which leaves behind inorganic mineral components
trickling filter
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
activated sludge
secondary wastewater treatment using the perfusion of oxygen through accumulated flocs to maintain aerobic digestion by microorganisms
tertiary treatment
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
chlorination
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
effluent
outflow water that is discharged to another treatment tank or released to a water supply
flocs
clumps of biomass consisting of adsorbed material and microorganisms
exopolysaccharide
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
secondary sludge
sludge that is a product of secondary treatment of wastewater, consisting of accumulated floc material
anaerobic sludge digester
large anoxic bioreactor operating in a semi-continuous mode that allows anaerobic digestion of remaining biowaste sludge following primary and secondary wastewater treatment
biochemical oxygen demand (BOD)
measure of the amount of dissolved oxygen required by microorganisms to decompose the organic matter in a sewage or water sample
persistent organic pollutants (POP)
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
biosolid
composted or treated sludge that is suitable for use as soil conditioner in horticulture and agriculture
fecal coliforms
group of coliform bacteria indigenous to the intestinal tract of humans and animals
indicator organisms
microbe, particularly fecal coliform bacteria, whose presence in a water sample indicates fecal matter is present and by association, potential intestinal pathogens
most probable number
presumptive test used to estimate fecal coliform bacteria numbers in a water samper
