Molds

Question 1

What species produce aflatoxins?

Answer 1

Aspergillus flavus and Aspergillus parasiticus

Question 2

Does pasteurization kill aflatoxins?

Answer 2

Yes

Question 3

Where is Aspergillus flavus common?

Answer 3

Food crops in tropical and warm temperate areas of the world.

Question 4

Where is Aspergillus parasiticus common?

Answer 4

Growth associated with peanuts , more geographically limited

Question 5

What is a requirement for high levels of aflatoxins in peanuts?

Answer 5

Infection while nuts are in the ground

Question 6

What are the major contributors to pre harvest infection?

Answer 6

high spore numbers
plant stress and drought (dry ground)
high soil temperatures

Question 7

How can we control spore formation?

Answer 7

crop rotation
irrigation
biocontrol

Question 8

How can we control aflatoxins in peanuts?

Answer 8

by manually sorting kernels after shelling

Question 9

How can we know which peanuts are infected by aflatoxins?

Answer 9

they can be blanched to remove the skin. the infected ones are discolored

Question 10

What removes all aflatoxins on peanuts?

Answer 10

alkali process used to make peanut oil.

Question 11

What are the 5 primary effects of Aflatoxin toxicity?

Answer 11

1) Acute toxicity
2) Liver carcinogenicity (develops after consumption of low levels over long period of time)
3) Liver cirrohsis
4) Immunosuppression (cell-mediated)
5) Growth retardation in children

Question 12

What does the liver convert aflatoxin to?

Answer 12

Epoxide

Question 13

What is the accepted safe level of consumption of aflatoxins for humans?

Answer 13

15 ug/ kg

Question 14

What is the level of aflatoxins in foods?

Answer 14

5 ug /kg

Question 15

What are the 3 groups of fungi producing ochratoxin A ?

Answer 15

1) ocher colored aspergillus (Aspergillus ochraceus, Aspergillus westerdijikae, Aspergillus steynii)
2) black aspergilli
3) pencillium species

Question 16

What organ does the ochra toxin target?

Answer 16

nephrotoxin

Question 17

Where geographically are there people with high blood ochra toxin?

Answer 17

Northern Europe, North America, and Northern Asia

Question 18

Although the mechanism of ochra toxin is unclear, what is probably related to?

Answer 18

phenylalanine

Question 19

How long can the ochra toxin stay in the blood?

Answer 19

3 weeks

Question 20

What is the tolerable ochra toxin intake?

Answer 20

100 ng/kg body weight

Question 21

How is OTA controlled?

Answer 21

Rapid drying (sun drying or mechanical dehydration)

Growth can be prevented in grapes by:

• proper irrigation
• regular pruning (air flow)
• use of crop cover
• fungicide application

Question 22

What are the effects of processing on ota with regards to fermentation for wines?

Answer 22

• removed when solids are removed

- finished wine has 1-8 % of ota originally there

Question 23

What are the effects of processing on ota with regards to coffee roasting?

Answer 23

enough roastin destroys the ota but highly contaminated batches are often destroyed

Question 24

What are the effects of processing on ota with regards to cereal processing?

Answer 24

65% reduction of ota in milling
10% additional reduction in the oven
-higher in whole wheat bread (less grain is discarded)

Question 25

What species produce fumonisins?

Answer 25

Fusarium verticilloids, related species | Aspergillus niger

Question 26

Where are fumonisins always present?

Answer 26

kernel of corn and sorghum Aspergillus niger : in grapes/raisins/coffee. It also releases the ota toxin which has synergistics effects with the fumonisin.

Question 27

Is colonization of fumonisins on kernels symptomless? How can it become dangerous?

Answer 27

Yes But when the plant is stressed (drought, heat, insects) it can lead to a disease in mycotoxin interaction

Question 28

How do fumonisins affect metabolism?

Answer 28

Affect sphingolipid metabolism - affects membrane proteins - inhibition of folate binding

Question 29

What is the dramatic disease in horses called and what toxin creates it?

Answer 29

equine leukoencephalomalacia by fumonin ingestion

Question 30

What do fumonisins do to pigs? to rats?

Answer 30

heart failure , liver cancer

Question 31

What do fumonisins do to humans?

Answer 31

esophageal cancer and neural tube defects (i.e spina bifida due to inhibition of folate binding)

Question 32

In the following countries: China, Iran, Northern Italy, Kenya, southern United States, corn consumption is high and so the people are exposed to high poisoning of which toxin?

Answer 32

fumonisins

Question 33

What do fumonisins contaminate?

Answer 33

corn preharvest

Question 34

What are some ways to control fumonisins?

Answer 34

- rapid drying of harvested corn (they do not grow at aw below 0.9) - good agricultural practices (irrigation) - fumonisin resistant corn

Question 35

What is Nixtamalization?

Answer 35

corn is soaked and cooked in alkaline solution - removes almost all fumonisins - in Central America

Question 36

What are the fumonisin resistance to dry and wet milling?

Answer 36

survive , high levels in bran and germ

Question 37

What temperature decreases fumonisins?

Answer 37

heated above 150 (which is why cereals and snack foods are low in fumonisins)

Question 38

What species produce deoxynivalenol DoN?

Answer 38

Fusarium graminearum in corn and small grain (wheat / barley) Fusarium culmorum in small grain (wheat / barley)

Question 39

What diseases does the deoxynivalenol toxin cause?

Answer 39

gibberella ear rot in corn and fusarium head blight in wheat and barley -> always pathogenic to the plant

Question 40

What does deoxynivalenol require to cause disease?

Answer 40

require spores (airborn or insect born) inoculation at susceptible times appropriate moisture and temperature usually occurs in the North

Question 41

What species produce zearalenone?

Answer 41

same species as DoN ( Fusarium graminearum and Fusarium culmorum)

Question 42

What is the toxicity like of zearalenone (ZEA) ?

Answer 42

low acute toxicity

Question 43

What toxin causes estrogenic metabolites in pigs, cattle, and sheep?

Answer 43

zearalenone (ZEA) Also linked to early puberty in girls in Hungary and Italy

Question 44

What are the two diseases ZEA causes in pigs?

Answer 44

``` vagina inflammation (vulvovaginitis) vaginal and rectal prolapse ```

Question 45

What is ZEA considered as in terms of toxicity?

Answer 45

hepatotoxic (liver) hematotoxic (red blood cells) immunotoxic genotoxic (cancer)

Question 46

Are aflatoxins B and G carcinogenic?

Answer 46

yes

Question 47

Is aflatoxin M1 carcinogenic?

Answer 47

maybe

Question 48

Is ochratoxin carcinogenic?

Answer 48

maybe

Question 49

Are fumonisins carcinogenic?

Answer 49

maybe

Question 50

Are ZEA and DoN carcinogenic?

Answer 50

not evaluated

Question 51

What are the mold genera most associated with foods?

Answer 51

Aspergillus, Fusarium, and Penicillum

Question 52

What is a mycotoxin?

Answer 52

Fungal metabolite that when ingested/inhaled/absorbed through the skin can cause disease in humans and domestic animals

Question 53

T/F one species of fungus can produce several mycotoxins

Answer 53

true

Question 54

Does the presence of spores indicate mycotoxin?

Answer 54

no | mycotoxins occur as the result of fungal growth

Question 55

Are mycotoxins resistant?

Answer 55

Yes they usually persist in food even though the fungus does not survive the processing

Question 56

When does growth and toxin production occur?

Answer 56

Can occur during any point: growing, harvesting, drying, storage

Question 57

Are effects of mycotoxins acute?

Answer 57

Almost never acute, due mostly to accumulation of low levels over time *this is why they are amongst the most neglected areas in medical science

Question 58

What are the four naturally occurring aflatoxins?

Answer 58

B1 B1 G1 G2

Question 59

What are aflatoxins excreted as in dairy cows?

Answer 59

M1 and M2