For example, some claim that pork is not allowed to be eaten because the Jews at the time (or perhaps they were just Israelites then, my religious history is poor) didn't prepare pork properly, resulting in trichinosis.
I've heard alternative explanations, such as kosher laws being enacted to ensure that the Hebrews did not assimilate into local (Egyptian perhaps) society and remained a distinct people. Or that, specific to pork, pigs were just not a good animal for that area (high water requirements in a low water region). One place I read said that it might have to do with the time period when the Jews entered Palestine after the exodus, because there were celebrations for the god Ishtar than involved consuming pork, and treligious leaders weren't keen on intermixed rituals.
Is there any historical evidence for claims like these?
The origins of the pork prohibition are a little mysterious. Richard A. Lobban wrote an article in 1994 that explains the origin of the pig prohibition as coming out of Egypt's upper classes in the Bronze Age.
His argument is that the pig became associated with the Egyptian god Seth, the "bad" god, the one who killed his brother Osiris, and were associated with defeated nomarchs of the Egyptian marshlands. Pigs thus gained a negative stigma, associated with defeat and bad things, especially among the ruling class (who were the victors). Pigs continued to be consumed by the common people. Pigs thus began to represent evil itself. He continues by noting that Moses was raised by the upper classes in Egypt, and this may have influenced the prohibition of pig consumption.
You can read the article here:
The prohibition probably continued as a way of differentiating certain groups, and creating identities of "self" and "other". The Muslims embraced the pork prohibition as it differentiated them from the Christians around them who were permitted to eat pork (allowed in Acts). The ancient Jewish people embraced the pork prohibition as it differentiated them from the people around them, at least on an ideological level. Archaeological evidence shows that they did actually consume pork, though not to any great degree.
hi! you'll find more responses in the FAQ
I can't answer your exact question about trichinosis. However, one thing that you should be aware of is that, regardless of any basis in specific diseases for considering pork specifically "unclean," there is an independent basis for considering it unclean based on the attributes of the pig, in Leviticus 11:
https://www.biblegateway.com/passage/?search=Leviticus+11%3A3-8%2CDeuteronomy+14%3A3-8&version=NIV
^3 You may eat any animal that has a divided hoof and that chews the cud.
^4 “‘There are some that only chew the cud or only have a divided hoof, but you must not eat them.^ The camel, though it chews the cud, does not have a divided hoof; it is ceremonially unclean for you. ^5 The hyrax, though it chews the cud, does not have a divided hoof; it is unclean for you. ^6 The rabbit, though it chews the cud, does not have a divided hoof; it is unclean for you. ^7 And the pig,^ though it has a divided hoof, does not chew the cud; it is unclean for you. ^8 You must not eat their meat or touch their carcasses; they are unclean for you.^
It still may be that the factual uncleanliness (or danger, I suppose you might say) of the pig actually inspired this entire way of categorizing animals, with the camel and hyrax and rabbit just collateral damage. I'd assume not, but I don't know and like yourself I await answers from the historians.