Development of a novel cocoa butter equivalent from tiger nut (Cyperus esculentus L.) oil via enzymatic acidolysis

In this study, tiger nut oil (TNO) was innovatively used as a novel, sustainable feedstock for cocoa butter equivalent (CBE) synthesis via enzymatic acidolysis. The catalytic activity of different enzymes was screened, and the reaction conditions were optimized using response surface methodology. The product was purified via molecular distillation and solvent fractionation. Meanwhile, the physicochemical properties of the purified product were systematically characterized. The results of the enzyme screening indicated that the low-cost immobilized Lipase 7000Pro demonstrated the superior catalytic activity to the immobilized Novozym 435. The optimal reaction conditions for preparing CBE using Lipase 7000Pro were 1.3:1 molar ratio of stearic acid to palmitic acid, 12.4:1 molar ratio of acid to TNO, 5.8 wt% enzyme loading at 70 °C for 5.7 h. Under these conditions, the CBE yield reached 90.63%. The physicochemical properties of the purified CBE, such as, total fatty acid composition (P: 24.14%, St: 35.58%, O: 33.79%), crystal form, were similar to that of cocoa butter (CB). Both CBE and CB predominantly exhibited the desired β crystal form. Triglyceride composition analysis revealed that the POP and POSt contents of CBE were similar to those of CB, but the StOSt content of CBE was lower than that of CB. Additionally, solid fat content analysis showed that CBE was soft than CB.