Kinetics of the cis-trans isomerization of linoleic acid in the deodorization and/or physical refining of edible fats

The cis-trans isomerizations undergone by linoleic acid during industrial deodorization and/or physical refining of edible fats were studied in an experimental discontinuous pilot plant of 250 kg using nitrogen as stripping gas in place of steam. For each oil, the expression of the analytical results has been made as molar fraction, which is kinetically equivalent to making an abstraction from the other components in the reaction bulk and assumes they do not take part in the isomerization. The kinetic constants for the formation of the acids C18:2(9c, 12t), C18:2(9t, 12c)and C18:2(9t, 12t) were determined. The equations and values obtained justify that the reaction orders studied are zero (or can be considered zero) for the time taken in an industrial deodorization and/or physical refining of edible fats. The analytical method used is appropriate for direct application of the results in industry.