• What is soapstock made of?
  • Soapstock consists of 70-95% water and 5-30% of fatty material, depending on the refining practice and the equipment used. Most of the fatty material, 60-70%, is in the form of sodium soaps of fatty acids with the remainder made up of triglycerides, phospholipids, and minor amounts of other oil-derived compounds [ 2].
  • What percentage of crude oil is soapstock?
  • Typically, soapstock will account for 5 to 10% of the crude oil mass, although higher values can be reached when the crude oil has a high concentration of free fatty acids [ 1]. Soapstock consists of 70-95% water and 5-30% of fatty material, depending on the refining practice and the equipment used.
  • How is soapstock formed?
  • Soapstock is formed by treating (refining) crude or degummed vegetable oils with alkali to produce a sodium soap, which is separated from the oil by centrifugation. Typically, soapstock will account for 5 to 10% of the crude oil mass, although higher values can be reached when the crude oil has a high concentration of free fatty acids [ 1].
  • Which soapstock is the best inducer for enzyme production?
  • Among the soapstocks evaluated, the sunflower soapstock was the best inducer for enzyme production, with 201 U/g dm (gram of dry medium) using 10 8 spores/g m (gram of medium) inoculated on wheat bran humidified with 80 mL of liquid (ammonium sulfate solution) that corresponds to a final concentration of 0.5% nitrogen, and 3% inducer.