I think you need to read the Incobrasas literature in more detail:
"A Technical Definition
Fuel-grade biodiesel must be produced to strict industry specifications in order to ensure proper performance. Biodiesel blends meet specifications for legal diesel motor fuel (
ASTM D7467). Also, B100 must meet the ASTM definition for biodiesel itself (
ASTM D6751).
Raw vegetable oil cannot meet these diesel fuel specifications and therefore is not considered biodiesel.
The technical definition of biodiesel is as follows:
Biodiesel, n - a fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, designated B100, and meeting the requirements of ASTM D 6751.
Biodiesel Blend, n - a blend of biodiesel fuel meeting ASTM D 6751 with petroleum-based diesel fuel, designated BXX, where XX represents the volume percentage of biodiesel fuel in the blend.
Producing Biodiesel
Biodiesel is made through a chemical process called transesterification whereby the glycerin is separated from the fat or vegetable oil. The process leaves behind two products – methyl esters and glycerin.
Methyl esters is the chemical name for biodiesel and glycerin is used in a variety of products, including soap."