Rapid synthesis of conjugated linoleic acid from fruit processing residues seed oil by alkali-dimethyl sulfoxide
isomerization

Rapid synthesis of conjugated linoleic acid (CLA) by the alkali-dimethyl sulfoxide
(DMSO) isomerization method is presented in this study. Seeds from fruit
processing residues in Thailand were screened as an alternative potential
source of linoleic acid (LA)-rich oil. Passion fruit with 72.10% LA and 26.18%
oil in the seeds was selected as starting oil. The Alkali-DMSO isomerization
was carried out by mixing DMSO with alkali hydroxides and polyhydric alcohols. Under a mass ratio of 1:0.5:1:1 oil/NaOH/propylene glycol/DMSO, at 180^oC, production of the major isomers of CLA (c9,t11, and t10,c12) was complete within 3 min, resulting in a 20-fold increase in productivity compared to the conventional method. The reaction time decreased because of an increment in the basic strength of the alkali-DMSO catalyst. CLA from alkali-DMSO isomerization and commercial supplements showed a similar isomer distribution and yielded similar CC50 values when evaluated against the Vero cell line. This method might be an alternative in industrial production as it is fast and simply applied to the conventional system. In addition, seed oils from fruit processing residues can be used as an alternative to traditional LA-rich oils.