Lipase-catalyzed modification of lard to produce human milk fat substitutes

The objective of the present work was to modify lard into human milk fat substitutes (HMFS) by Lipozyme RM IM-catalyzed acidolysis. Lard and soybean fatty acids were esterified in a solvent-free system. The reaction substrates for HMFS production were specially chosen to mimic human milk fats. Factors such as temperature, time, water content, enzyme load, substrate ratio, and enzyme reusability were investigated. The relationships between initial incorporation rate (Inc/h) and temperature (T, K) were set up, based on the Arrhenius law for both linoleic and for linolenic acids. Scale-up trials were carried out to confirm the feasibility of enzymatic modification for the production of HMFS. The characteristics of the product, produced in the scale-up acidolysis under selected conditions (temperature 61 °C, water content 3.5%, lard:fatty acids 1/2.4 (mol/mol), Lipozyme RM IM load 13.7%, and time 1.0 h), were similar to the fat in Chinese mothers' milk. The results showed that it was possible to produce human milk fat substitutes from lard through enzymatic acidolysis with soybean fatty acids.