I got this code but it is not inserting the content of the option (textarea) into the database.
You need to name your select with name=food or something so it will be in $_POST['food']. Each option in the select does not show up in $_POST, only what is selected will be in the name of the select. Each option is not it's own thing.
When you save the data it will have:
$_POST['food'] with the value of 'foodA' if multiples, it will be 'foodA, foodB'