Yes it does apply to Soybean also. All vegetable oils (olive, canola, soy, etc) normally will go rancid in liquid form. The process of hydrogention heats the oil to some incredibly high temperature, causing a molecular change. The result of this process is that it keeps the oil from spoiling, which is why it's so prevelent in processed foods. A package of cookies or potato chips can sit in a vending machine for years without spoiling. Unfortunately, this hydrogenation process is what makes the oil very very bad for us.