When there is food in a suitcase or hand-luggage is it permitted lechatchila to bring it into the bathroom?
This may sound surprising to you, but according to the basic halacha one is allowed to bring food into the bathroom even if it isn’t covered, and it is permitted to eat it even if it didn’t have any covering. The reason is, because the ruach ra in the bathroom only affects one’s hand, but not food and drinks that are brought into it. There are those however that are careful that the food should be covered, however one covering is surely enough. Therefore there is no problem with taking a suitcase that has food inside it into the bathroom.
Be’er Hetiv 64-2, Be’er Moshe 8-41, DIvrei Yatziv Y:D 34, Teshuvos Vhanhagos 1-11, Piskei Teshuvos siman 171-9.