Pork contains a parasite called Trichinella spiralis.
This is a pathogenic parasite ingested by pigs (also bear and horse).
This parasite will penetrate into muscle joints in the living animal.
If the pork is subsequently undercooked, the parasite will survive and enter the small intestine of the new host.
The T spriralis larvae are protected by nurse cells, which, when in contact with the stomach acids, release the larvae into the small intestine, where they will grow to maturity and release up to 1500 larvae, per female adult, into the blood stream and lymph system.
Initial symptoms of nausea, vomiting, stomach cramps and diarrhoea, can start in as little as 3 days after eating undercooked meat.
Other symptoms include fever, general malaise, respiratory disorders, disorders of the central nervous system and eventual death.
Some religious faiths do not eat pork as it is classed as unclean.
The uncleanliness is due to this parasite.
So always cook pork and pork products (or bear/horse products if available) to a core temperature of 75 degrees Celsius to guarantee food safety.
Freezing will not kill the parasite, as it is protected by an encrusted cyst.
Therefore even freezing the meat before cooking will not allow undercooking.
Fresh fish, however, can be safely undercooked if frozen first.
Do not under any circumstances eat undercooked fresh fish as they also contain parasitic infection.
The main problem parasites are Anisakis simplex, andPseudoterranova decipiens.
The main symptoms are the immune reaction by the body's defences, such as nausea, vomiting, stomach pains.
Surgical procedures have sometimes to be adopted to remove the parasites.
Undercooking fresh fish or eating raw fresh fish can lead to this infection.
Under UK legislation, all fish used for Sushi as a raw ingredient, must be frozen at -20 degrees Celsius for at least 24 hours.
It can then be defrosted and used as fresh, which ensures food safety.
"The freshest fish to eat is frozen fish".
This is because fish caught at sea or fresh water, meant for freezing, is frozen within 1 hour of capture.
Fresh fish, however, can take as long as 7-10 days to reach the supermarket or fishmonger.
If the fish has not been refrigerated during the 7-10 days, further complications can arise, such as the build up of toxins or bacteria.
One such toxin is scombrotoxin.
This is a poison which develops in fish that has been temperature abused between capture and sale and is a serious food safety hazard.
Histidine in the fish develops into Histamine, causing an allergic reaction to the consumer.
This could result in anaphylaxis, which is life threatening.