There are lots of recipes that call for the use of lemon juice when marinating chicken. There is a reason why the recipes states how long you should marinate. If you marinate meat in lemon juice (or other citrus acids like orange juice) for too long, it will begin to cook the meat. So, in this case, longer is not necessarily better!!!
True story – I once brought grilled shrimp to a concert at Chastain in Atlanta. I was so excited but when we ate them they tasted like mush. They marinated too long in lime/garlic and then I grilled them to essentially cook them a second time. Nasty! Haven’t made that mistake again. -Melissa