Reusability test was performed by a simple squeezing using soybean oil as the model. Typically, an accurately weighed amount of CGF (50 mg) was immersed into 50 mL soybean oil for 15 min at room temperature. After filtration by a stainless steel mesh, the wet fiber was drained for 10 min and then weighed. This oil absorption capacity was calculated and recorded as the initial one. Subsequently, the oil-absorbed fiber was squeezed to ensure that as much oil as possible was squeezed out, and the fiber was then used for another absorption. The reusability expressed by the re-absorption percentage was calculated from the weight ratio of re-absorption capacity to initial one.