Question

What is oil moisture ? What is it useful for?

Answer 1

Dissolved moisture is low level of moisture contamination in oils used for lubricating.  

This moisture is obtained from ambient air humidity slowly interacting with lubricant oil overtime.  

Normally more additives the oil contains more hygroscopic (water attracting) the oil will become eventually.

Major use of cooking oil is in frying where it functions as heat transfer medium and contributes flavor and texture to foods.