Lecture 6: Toxins in Food Flashcards

1
Q

Toxicology

A

The study of poisons and more specifically the adverse effects of chemicals on living organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Food toxicology

A

The study of toxic substances in the human food chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Food poisoning

A
  • Illness from consuming food that contains a harmful substance, harmful microorganism, or toxin produced by a microorganism
  • Can result in short-term symptoms, long-term disease and death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Natural contaminants vs. Man-made contaminants

A

Natural:
-toxins produced by the plant or animal
-normal components of food
Man-Made:
-Chemical (pesticides, cleaning agents, antibiotics, toxins produced during cooking)
-Physical (dead insects, hair, glass, metal)
-Biological (microorganisms like bacteria, viruses, mold, fungi)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is food toxicology deeply rooted in the history of human civilization?

A

Our ancestors had to learn through trial and error which foods were harmful and which were safe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Red Emperor Shen Nung

A
  • Father of Chinese traditional medicine
  • Noted for tasting 365 herbs
  • Discovered tea
  • Taught people how to cultivate grains as food –> less reliance on animals
  • Wrote “The Great Herbal”
  • Died of a toxic dose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ebers Papyrus

A
  • Oldest, well preserved medical document from ancient Egypt

- Contains a collection of info on anatomy and physiology, toxicology, spells, treatments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Homer (Greek)

A

Wrote of the use of arrows poisoned with venom in “The Odyssey” and “The Iliad”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Socrates

A
  • Chared with religious heresy and corrupting the morals of local youth
  • Committed to death by Hemlock (alkaloid coniine causes paralysis and death when ingested)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Paracelsus

A
  • Father of toxicology
  • “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy.”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mateu J.B. Orfila

A
  • Proficient in the chemistry of crime scene investigation and was an early promoter of chemical evidence in the courtroom
  • Founder of forensic toxicology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Toxicity vs. Hazard

A
  • Toxicity = capacity (potency) of a substance to produce injury
  • Hazard = probability that injury will result from use of a substance in a prescribed quantity and manner (includes levels of “how much”)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Equation for risk

A

Risk = exposure x inherent toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does the FDA protect the U.S. food supply?

A
  • Conducts tests, sets standards, and enforces laws regulating food quality and processing
  • Regulate food colors and additives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does the USDA protect the U.S. food supply?

A

USDA regulates and inspects meats, poultry, eggs, and dairy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does the EPA protect the U.S. food supply?

A
  • Responsible for establishing tolerances for pesticide residues in or on foods and feeds
  • Tolerances are legal limits of the amount of pesticide residues that can be found on a raw agricultural commodity at the farm gate or in a processed food
17
Q

List the food hazards in order of concern by regulatory agencies

A
  1. Microbial
  2. Nutritional
  3. Environmental
  4. Natural toxicants
  5. Pesticide residues
  6. Food additives
18
Q

According the the CDC, how many people suffer from food borne illnesses each year?

A
  • 48 million suffer
  • 128,000 hospitalizations
  • More than 3,000 deaths
19
Q

Dose response curve

A
  • Plot of dose vs. response
  • Determines potency of compounds
  • Determines how much of a compound we consume
  • Estimates risk of compounds
20
Q

LD50

A

Lethal dose when 50% of population dies

21
Q

Acute vs. chronic exposure

A
  • Acute = one dose or exposure over a very short period of time (< 1 week)
  • Chronic = multiple doses which occur over an extended period of time (> 1 week)
22
Q

Acute vs. chronic toxicity

A
  • Acute = lasts a few minutes, hours, weeks

- Chronic = can last months, years, a lifetime

23
Q

Paralytic shellfish poisoning

A
  • Onset = 30 - 60 mins
  • Symptoms = tingling, burning, numbness, drowsiness, incoherent speech, respiratory paralysis
  • Duration = respiratory support within 12 hours or exposure results in complete recovery
24
Q

Dinoflagellates

A
  • Marine phytoplankton responsible for algae blooms (red tides) that occur in the warmer months
  • Poduce saxitoxin
25
Q

Ciguatoxin

A
  • Caused by eating tropical and subtropical fish (barracuda, red snapper, sea bass)
  • Obtained from food chain (large carnivorous fish eat small fish that eat algae that have eaten toxic dinoflagellates)
  • Not destroyed by cooking
  • Has no effect on the host fish (no difference on appearance)
26
Q

Ciguatera fish poisoning

A
  • Onset = less than 6 hrs
  • Symptoms = gastrointestinal (nausea, vomitting, diarrhea); neurological (numbness and tingling around mouth, joint pain, muscle ache, headache, temp sensory reversal, extreme exhaustion)
  • Duration = usually goes away on its own within several days; rarely some neurological symptoms may persist for months or years
27
Q

Tetrodoxin (Fugu)

A
  • Fugu = Japanese delicacy made from puffer fish or blowfish

- Contains a lethal poison called tetrodotoxin in the liver and ovaries

28
Q

Cyanogenic Glycosides

A
  • About 150 species of plants produce cyanogenic glycoisides
  • Release HCN when plant is chewed
  • Not toxic by themselves but when a plant is chewed, the glycoside is broken down by an enzyme and HCN is released
  • Acts as a defense mechanism to discourage animals from eating it
  • Sources = bitter almonds, lima beans, cassava root
29
Q

Cassava

A
  • Staple food and major carb source in tropical areas

- Starchy roots produce more calories per unit of land than any other crop in the world

30
Q

How are cyanogenic glycosides removed from cassava in order for it to be eaten?

A

Roots of cassava are scraped or grated, soaked in water and fermented for a few days

31
Q

Glycoalkaloids

A
  • Toxins from the plant genus Solanacea (potatoes, tomatoes, eggplant, nightshade)
  • Solanine in potatoes can be toxic
32
Q

Potatoes and solanine

A
  • Solanine is found in the sprouts, right under the peel, and in sun-greened areas of potatoes
  • When potatoes are exposed to light, solanine levels can rise to 10x their original value
  • Solanine levels in potatoes are associated with a green skin color caused by the formation of chlorophyll
  • The greener the potato, the more likely it is that it contains high concentrations of solanine
33
Q

Green potato poisoning

A
  • Rare
  • Poisoning can result form ingestion of potato sprouts, sprouted potatoes, and especially green potatoes
  • Symptoms = gastrointestinal upset, headache, fever, convulsions, drowsiness, rapid breathing, delirium, and coma
34
Q

Polycylic Aromatic Hydrocarbons

A
  • Formed by the incomplete combustion of organic material and occur in the residue of smoke
  • ore than 100 distinct PAHs are known
35
Q

Acrylamide

A
  • Starch-rich foods can contain high levels or acrylamide
  • Known carcinogen in rats and a probable carcinogen in humans
  • Formed in foods during baking and frying
  • Forms when foods rich in asparagine are cooked in temps greater than 248 F
36
Q

Lanape potato chip

A
  • To make a good potato chip, you need a potato with a high level of starch
  • In the 1960s, a group of researchers teamed up with the USDA to breed a high starch potato they named “Lenape” that made great potato chips
  • Turned out to be toxic b/c of high solanine levels of the breeding stock
  • Recalled ~ 1974