Process optimization of simultaneous enzymatic production of 1,3‐dioleoyl‐2‐palmitoylglycerol and 1‐oleoyl‐2‐palmitoyl‐3‐linoleoylglycerol

Abstract 1,3‐dioleoyl‐2‐palmitoylglycerol (OPO), a structured triacylglycerols (TAG) containing palmitic acid at sn ‐2 position, is widely used as breast milk fat substitutes in infant formula. Interestingly, the main component of breast milk fat in Western countries is OPO while Chinese breast milk contains both 1‐oleoyl‐2‐palmitoyl‐3‐linoleoylglycerol (OPL) and OPO. Thus, OPL is additionally essential for Chinese infants. In the present study, we developed a process for simultaneous production of OPL and OPO. According to the fatty acid (FA) composition of Chinese breast milk, soy oil, palm kernel stearin, and palm stearin were selected as the base oils for random interesterification, and the appropriate ratio was determined as 2:3:15. Then interesterification at sn ‐1,3 position was conducted, four reaction parameters were examined, where 1.6 molar ratio of oleic acid to linoleic acid (OLA/LNA), 10% enzyme quantity, TAG to FA ratio of 1:8 and reaction temperature of 56°C were ultimately established as the optimal conditions to achieve the target of the present study, and the OPO and OPL contents in the final products were 23.1% and 26.2%, respectively. Finally, molecular distillation was applied to purify above achieved breast milk fat substrates. Higher oil dropping speed, oil temperature, and agitation speed were favorable conditions, and the lowest acid value that achieved in the present study was 3.46 mgKOH/g. Overall, we established an efficient preliminary process for the simultaneous production of OPO and OPL, which could provide an important reference for commercial production of breast milk fat substrates for Chinese infants.