Production and Characterization of β-Cyclodextrin Inclusion Complexes Containing Conjugated Linoleic Acid from Njangsa (Ricinodendron heudelotii) Seed Oil

Abstract

Njangsa seed oil (NSO) is rich in polyunsaturated fatty acids and represents an underexplored plant source for producing conjugated linoleic acid (CLA). This study explored the production of CLA from NSO via alkali isomerization, as well as and its stabilization by β-cyclodextrin (β-CD) inclusion complexation. A 3-factor factorial design was used to optimize reaction conditions, yielding a maximum purified CLA content of 46.42% from 2.5 g NSO at 180 °C for 3 h, with cis-9, trans-11 CLA as the predominant isomer. Inclusion complexation produced microparticles averaging 19.73 µm with 83.36% inclusion efficiency. Complexed CLA showed lower peroxide, para-anisidine, and thiobarbituric acid values than free CLA, indicating improved oxidative stability. Fourier transform infrared spectroscopy showed spectral changes consistent with interactions between the CLA-rich fraction and β-CD, while scanning electron microscopy and X-ray diffraction revealed changes in morphology and crystalline organization, respectively. These findings demonstrate the feasibility of producing NSO-enriched CLA and enhancing its oxidative stability through β-CD inclusion complexation.