TOXIN IN FOOD

Question 1

Toxins

Answer 1

• Substances created by plants and animals that are poisonous (toxic) to humans.

• May also include some medicines that are helpful in small doses, but poisonous in large amounts.

• Most toxins that cause problems in humans come from germs such as bacteria.

Question 2

TYPE OF TOXINS

Answer 2

• Marine toxins
• Endegenous toxins
• Pesticides
• Environmental
• Microbial

Question 3

MARINE TOXIN

Answer 3

1) Scombroid poisoning
2) Saxitoxin
3) Tetrodotoxin
4) Ciguatoxin

Question 4

Scombroid poisoning occurs after the ingestion of:

Answer 4

• Tuna
• Skipjack
• Bonito
• Mackerel
• Mahi-mahi

Question 5

Scombroid poisoning

Answer 5

• Scombroid can result from inappropriate handling of fish during storage or processing.

• One of the toxic agents implicated in scombroid
poisoning is a chemical called histamine.

• Histamine → not destroyed by normal cooking
temperatures

• Histamine is a mediator of allergic reactions, so the symptoms → see in severe allergic responses.

• The suspect toxin is an elevated level of histamine generated by bacterial breakdown of histidine in the muscle protein through elevated production of the enzyme histidine decarboxylase.

Question 6

Scombroid poisoning onset

Answer 6

Immediate – 30mins, duration of illness normally 3 hours but may last for several days.

Question 7

Symptoms of Scombroid poisoning

Answer 7

• After ingestion or within 2 hours, patient shows several effects such as nausea, vomiting, and diarrhea, as well as epigastric distress.

• Headache and burning sensation of the throat.

• Followed by neurological numbness, tingling, and cutaneous flushing.

Question 8

Saxitoxin

Answer 8

• Species of dinoflagellates.

• Produce a toxin that accumulates in clams, mussels, and other shellfish that fed on the algae.

• Has no ills effect to the shellfish, but dangerous to
human.

• LD50 is 10ug/kg in mice

Question 9

Saxitoxin (Symptoms)

Answer 9

• Symptoms develop after 30 mins to 2 hours after
ingestion.

• Symptoms:
• Has direct effect on the heart, and block action potentials in nerves and muscles.
• Respiratory paralysis.
• Death may occur if respiratory support not provided (cardiovascular collapse).

Question 10

Tetrodotoxin

Answer 10

1) 90 sp. puffer fish, including :
• Blowfish
• Toadfish
• Fugu (sold in Japanese restaurant)

• Poisoning may be caused by improper preparation or removal of ovaries, roe, liver, intestines, and skin → High concentration of tetradotoxin.

• Toxin found nearly all tissues & stable to boiling
temperature unless made alkaline.

• Highest amount → spawning period

• Result in paralysis in CNS & peripheral nerves

Question 11

Symptoms of Tetrodotoxin:

Answer 11

• Appear usually 10mins – 45mins after ingestion, however lag time of 3 h or more has been observed.
• Tingling sensation, Malaise, Dizziness, Nausea, Ataxia, Diarrhea, Subcutaneous Hemorrhage, paralysis, Cyanosis, Convulsion. 40% -60% death

Question 12

Ciguatoxin

Answer 12

• Ciguatoxin, an ichthyosarcotoxin, is produced by
more than 300 species of fish.

• Many fish caught for food have ciguatoxin
→ feeding habits (ingest plant that contain toxin).

• Ciguatoxin, an ichthyosarcotoxin, is produced by
more than 300 species of fish.

• Many fish caught for food have ciguatoxin → feeding habits (ingest plant that contain toxin).

• Ciguatoxin is water soluble and heat stable hydroxylated lipid molecule whose structure is unknown.

• Ciguatoxin inhibits cholinesterase, resulting in synaptic acethylcholine accumulation and disruption of nerve function.

• Death is usually attributed to respiratory paralysis.

Question 13

Symptoms (Ciguatoxin):

Answer 13

• Ciguatoxin poisoning begins with tingling of lips, tongue, and throat and is rapidly followed by numbness in those areas.

• It may take up to 30h following ingestion of the fish for symptoms to appear.

• Nausea, vomiting, abdominal pain, with intestinal spasms, and diarrhea soon follow.

• About 7% result in fatalities.