Although I understand that Noach was not Jewish, G-d clearly punished the world because of the sin of the people. If there was no Torah, then why was sin punished? Why was Noah and his family sanctified, set apart from the rest of the world through a huge Mikvah, lands on Mt Ararat on the days of First Fruit (17 Nissan). G-d is clearly applying the Torah here. Surely after all that G-d can not tell Noah to eat something He later forbids? That might imply that G-d has changed His mind, yet the scripture tells us that G-d is unchangeble Blessings of Shalom: Baruch Abels

The world was punished in the time of Noach because they didn’t observe even the most basic and elementary morality, for which every human being was obligated, even before the giving of the Torah. Idolatry, adultery, murder, and theft are not so demanding, yet even that, they transgressed. Impure animals are not forbidden for non-Jewish consumption, not before the giving of the Torah, and not afterwards, not for Noach and not for Barak Obama. Just as if I, as a non-Cohen, were to give a sacrifice or chant the priestly blessing, it wouldn’t have Torah significance, and similarly, there’s no reason for me not to go to cemeteries, because I'm simply not a Cohen. So too, there’s no reason for a non-Jew to wear tfilin, nor abstain from bacon. Even if Noach gave kosher sacrifices, that has nothing to do with his own personal diet. In short, God is exact regarding every commandment, regarding who, what, where, when and how they are obligated or exempt, and it's not our place, nor Noah's, to "invent" new commandments when they don't apply. With Love of Israel, Rav Ari Shvat