Effects of Rhodium Heterogeneous Catalyst and Isomerization Conditions on Linoleic Acid Conjugation of Soybean Oil

Abstract

Rhodium heterogeneous catalyst was used to catalyze isomerization of linoleic acid in soybean oil to conjugated linoleic acid (CLA). A central composite rotatable design with five levels of three variables, namely, reaction temperature, stirring speed, and reaction time, was used to determine the maximum CLA yield. The formation of CLA during isomerization was greatly dependent on the reaction temperature and time. The CLA content of soybean oil increased from 0.63 to 202.42 mg/g oil when isomerization was done at 200 degrees C, with a stirring speed of 200 rpm for 49 min. Analysis of triacylglycerol positions showed that linoleic acid at any position in a triacylglyceride could possibly be isomerized to CLA.

Conjugated linoleic acid formation by hydrogenation/isomerisation of safflower oil over bifunctional structured catalyst Rh/SBA‐15

“…However, the composition of CLA isomers also varies with the temperature. This tendency was also reported by Pakdeechanuan et al (2005) when they hydrogenated soybean oil over 5% Rh/C catalyst. According to Table 2, the trans/trans CLA isomer concentration clearly increased when the temperature increases from 180 to 210 • C, whereas both 9-cis, 11-trans C18: 2 and 10-trans, 12cis C18: 2 health beneficial CLA isomers, attained a concentration of ca.…”

Modified soybean oil as a reactive diluent: Synthesis and characterization

“…Homogeneous and heterogeneous metal catalysts, enzymes, and photocatalysts have been used to conjugate vegetable oil. For a laboratory scale, it was convenient to use a catalyst previously report by Larock and coworkers .…”

Synthesis and properties of soy hull‐reinforced biocomposites from conjugated soybean oil

“…With an average of 4.5 double bonds per triglyceride,10 soybean oil is only moderately active toward free radical species, but the reactivity can be considerably increased by the conjugation of the carbon–carbon double bonds of the fatty acid chains. Several studies regarding the double‐bond isomerization of vegetable oils have been reported in the literature 16–19. Our group has developed a homogeneous isomerization procedure employing [RhCl(C 8 H 14 ) 2 ] 2 as a precatalyst 20.…”

“…Several studies regarding the double-bond isomerization of vegetable oils have been reported in the literature. [16][17][18][19] Our group has developed a homogeneous isomerization procedure employing [RhCl(C 8 H 14 ) 2 ] 2 as a precatalyst. 20 The reaction yields >95% conjugation for several vegetable oils tested and has been frequently used in our work on bioplastics.…”