small amount of an easily detected substance that can be used to follow and quantify the flow of materials or movement of organisms not otherwise visible or detectable by ordinary means
a substance (as a radioactive isotope or a dye) with distinctive properties that is introduced into a system so that its subsequent distribution may be readily followed
The fat content may be equal to or less than 82 %, and it may be used according to a number of processing methods relating to any concentration and addition of tracers.
