I would be afraid to eat something that was opened & stored tightly in the refrigerator for 1 week...............I would get rid of that.....better to do that then take a chance of getting sick from it bacteria builds up even if it is tightly sealed & kept very cold.
Next time you open something and it is too much to eat within 3 days......freeze it into small servings not to waste anything. We only keep something cold for 3 days and longer than that it would be trashed. Our family had several eateries.....and 3 days was the limit for cold food storage that had to have the date on it.