All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is feared that this may be backbiting if the lack of salt is a defect and the maid who cooked the food is offended by this being mentioned. Scholars have defined backbiting as mentioning something about a person which he hates in everything related to him, whether in his body, his actions, his wealth, or otherwise.
Allah knows best.