As you may already know fiber is what make the structure of fruits and vegetable and cannot be digested. They are also considered carbohydrates that do not provide nutrients. Eating food reach in fiber help eliminating body waste and can eliminates some cancers and lower the blood cholesterol.
There are two types of fiber. Soluble fiber and insoluble and both absorb water more or less. In order to break the fiber in cooking process different techniques are applied like steaming, boiling, saute, baking grilling ond few other. Adding sugar to fruits along cooking process increase or mentain the fiber.
Adding baking soda to your vegetable in boiling process can preserve some of the color but will break up the fiber faster resulting in mushy vegetable and it should be avoided