Development of symmetric monounsaturated triacylglycerols by Rhodosporidium toruloides cell factory for cocoa butter equivalent

In the present study, various factors including carbon source, nitrogen source, Mg2+, and pH value were investigated to determine the optimal conditions for producing cocoa butter equivalent using R. toruloides. The maximum of biomass, lipid content, and lipid production were achieved at levels of 7.8 g/L, 61.0%, and 4.4 g/L, respectively. The oil from R. toruloides mainly consisted of 16:0, 18:0, and 18:1 with 18:1 dominating at the sn-2 position, which was further confirmed by C-13 NMR analysis. UPLC-MS analysis showed that the sum of sn-POP, sn-POS, and sn-SOS accounted for up to 27.11% in the triacylglycerol species of the oil produced, which allows those triacylglycerols to be further separated and isolated from other triacylglycerols and used for cocoa butter equivalent. Notably, the production of cocoa butter equivalent reached 1.13 g/L, demonstrating the scientific feasibility of producing CBE through fermentation. These findings indicate a promising future for the fermentation-based production of cocoa butter equivalent.