I asked this question on another sub but thought I might get even more useful responses here.

Growing up, I was always told not to peel garlic and onions or cut them until right before they are used because doing that would alter the flavor and they wouldn’t be as potent. I was also told not to wash berries, mushrooms and potatoes until it’s time to cut or eat them and not to cut things like lettuce, broccoli, zucchini, tomatoes, etc ahead of time because they’ll go bad within a day or two rather than lasting longer if they were uncut.

I’m pretty sure some if not all this information is wrong. Can you please explain if there’s any truth to this? It would be so great to be able to prep a few things each week but I’m just not sure what items I can actually prep without altering the flavor, texture and longevity of the item.