Unit 8A Flashcards
What are the 6 main causes of unsafe food
pathogenic organisms natural toxins extraneous matter harmful additives allergens
which one is of most concern?
pathogenic organisms
why are pathogenic organism so prevalent?
globalization of trade
how much does food poisoning cost each year?
$20-$45 billion each year
what does food microbiology address?
food waste and spoilage, fungi and bacteria
do viruses proliferate in foods?
no - so they don’t cause food spoilage! although they do cause a large umber of food borne illnesses, they are pathogenic
5 types of pathogenic microogarnisms: bacteria, virus, worms, fungi, protozoa
microbiological analysis
analyzing mircorganisms in food, under the food quality control (QC)
what is normalizing used in microbiological analysis?
standard plate count
do many foods have an upper limit set for microbial total load?
yes, determined by standard plate count
what is the standard for Grade A milk prior( before) to pasteurization?
can’t exceed 100,000 per ml
is identification of micro-organisms an easy process?
no, >80% food poisioning unknown
talk about spores
some bacteria species can form spores, which are dormant and extremely resistant to adverse conditions
when conditions become favourable they awaken and become VEGETATIVE CELLS
size difference of bacteria and yeasts and holds
bacteria are 1-4 microns and yeasts are 20 microns
holds are larger than yeasts
how do holds grown
in multicellular filaments called hyphae
what is hyphae
multicellular filaments of mold
what can microorganisms be comparable to
enzyme factories
what is better at growing in lower moisture content
molds
mesophilic
20-45 degrees
thermophillic
(heat loving) above 45
psychrophillic
cold loving, below 10
psychrotrophic
fridge temperature
obligate vs facultative
obligate require certain conditions either anaerobic or areobic while facultative can adapt to either
food infection vs food intoxication
food infection is when a pathogenic microorganism establishes itself inside the intestine and causes and infection
food intoxication is when a microorganism produces toxins that cause illness ( rapid onset )
taxonomy
genus and then species then subspecies or sterotype
listeriosis
frigde disease
campylobacteriosis
raw poultry
spores that produce botulism can’t germinate and a pH of less than ?
4.6
staphylococcal
from food handelers
mycotoxins
from molds
aflatoxin
mycotoxin that results in liver damage
shiga toxin producing E.coli
more than 700 strains of E.coli are know and some are beneficial to the gut flora
the shiva-toxin- producing E.coli are harmful and produce toxins in the intestines and can cause lysing of RBC
example is the “hamburger disease” (0157: H7)
viruses
harder to detect, dont cause food spoilage, cause food borne illnesses
examples; norovirus, hepatitis A and polio
which virus is responsible fro 50% of outbreaks in NA
norovirus
toxoplasmosis
caused by protozoon parasite
trichinosis
worm in bloodstream “ macrobiological “
anisakis
from raw fish
prevented by freezing -35 for 15 hours or -20 for 7 days
blast frezzing
-35 for 15 hours
drying preserves by lowering ?
water activity
why add sugar or salt
because it draws out water from microbial cells
smoke
formaldehyde heat and dehyradtion
can holds grow on jam
yes, moldscan tolerate less water activity and sugar and salt more than other microorganisms
