chapter 41

clostridium botulinum
carried on baked potatoes (aluminum foil) or spreadable tomato paste– toxins cause respiratory failure
clostridium perfrigens
causes 24 hour infection with ab cramps and diarrhea — high infectious dose
bacilius cereus
causes 2 types intoxication: manifests as diarrheal illness or accute vomitting
food intoxication indicated by
1) symptoms shortly after food consumption
2) toxins in food are associated with the microbes in the food itself that are creating the toxin
food-borne infection
involves ingestion of pathogen and growth in host
making wine is called
enology
In wine production, “must”
liquid produced after grapes are crushed
molds make _______ that break down food, which leads to _______ growth
1. enzymes
2. bacteria
when meat is cooked, its surface becomes a ______ environment
reducing
when meat is ground up it is _____ likely to spoil bc of increased ______
1. more
2. surface area
mesophilic milk fermentation makes
sour cream and buttermilk
thermophilic milk fermentation makes
yogurt
yeast-lactic fermentation creates
kefir
mold-lactic fermentation creates
viili
in thermophilic fermentation of milk to yogurt, the microbes flavor the yogurt with ____ and ____
acetaldehyde and diacetyl
high hydrostatic pressure
high pressure for 5-15 mins with no temp changes
radapperization
gamma radiation to preserve canned foods
Shrink wrapped foods lead to
increased microbe growth bc O2 diffuses through wrap
Microbes are filtered from liquids by _____ and _____
pre-filtration and centrifusion
Pathogenic microbe listeria monocytogenes dangerous bc
it grows at refrigerator temps
Pasteurization is done by
heating low to medium heat for short period to kill pathogens
Xerophiles
microbes that live in low aw temps like for cereal or dried fruits
Frozen juice concentrates lead to growth of yeasts/grahm positive bacteria that cause the juice to _____ when water hits
spoil
Freeze drying _______water activity and ________osmolarity
1. decreases
2. increases
3 main principles for developing good food safety policies and methods
1. speed
2. simplicity
3. specificity and sensitivity for a given pathogen
Immunoogical methods used for identification of cultured food-borne pathogens include ____ antibody tagging and ____
1. fluorescent
2. ELISAs (enzyme-linked immunosorbent assays)
PCR
can detect a few target cells without needing pure cultues
Which of the following microbial genera is used in the production of fermented dairy products?
1. streptococcus
2. lactobacillius
3. leuconostoc
production of natural carbon dioxide by yeasts after a wine is bottled results in
champagne
T/F
Stretococcus thermophilus and Lactobacillius bulgaricus contribute to the flavor of yogurt by producing diacetyl during the fermentation of lactose
true
T/F
When lactobacillius acidophilus are sprayed on feed, the cattle that it it appear to have markedly lower carriage of the pathogenic E. Coli strain 0157:H7
true
T/F
Temperature and humidity are important intrinsic factors in determining the rate of food spoilage
False– extrinsic
The holes in swiss cheese are produced by the metabolic activities of which bacterial genus?
Propionibacterium
A major cyaobacterial food source used in many parts of the world is
Spirulina
Bread products can be spoiled by the growth of Bacillus species that produce
ropiness
a major fungal genus that produces aflatoxin is
aspergillus
T/F
Growth of yeasts and molds will be favored in more acidic foods
True
which of the following can function better at a lower ph?
yeasts and molds
T/F
filtration is sometimes used to remove organisms from beer bc it has less effect on the flavor than pasterization
True
factor that determines if wine is dry or not is based on
the amount of sugar after fermentation
the process of racking, used in wine production involves
removal of sediments
the process of beer lagering involves
aging
the largest meat recall in US history was prompted by the discovery of contamination by
listeria monocytogenes
a major organism involved in the production of ergot is
claviceps purpura
ergotism involves microorganism production of
hallucinogenic alkaloids
Mashing is a process involving
carbohydrate hydrolysis
T/F
lysozyme is an important antimicrobial substance found at high levels in which food vegetables
false (egg/milk)
Aflatoxins are planar, ringed compounds that interact with DNA by _____ and cause frameshift mutaions
intercalation
major organism considered to cause food-borne infection is
salmonella
T/F
some fermented dairy products have been suggested to have beneficial effects, including reduction in the incidence of colon cancer and th eminimalization of lactose intolerance
true
microorganism that has been used in the production of sour mash whiskey is
Lactobacillius delbrueckii