Treatment of milk fat with sn-2 specific Pseudozyma antarctica lipase A for targeted hydrolysis of saturated medium and long-chain fatty acids

Milk fat was treated with the sn-2 specific PAN-2 lipase from Pseudozyma antarctica with the aim of achieving selective removal of saturated fatty acids with chain lengths between C12 and C16, which are abundant at the sn-2 position. Hydrolysis was also carried out using the non-specific CRU-NS from Candida rugosa and the 1,3-specific TLA-1,3 from Thermomyces lanuginosus. PAN-2 treatment decreased the proportion of the target fatty acids considerably (content of 28%, w/w) and increased the proportion of unsaturated ones (content of 52%, w/w) at the degree of hydrolysis of 48% (mol/mol) in relation to the unhydrolysed substrate (47%, w/w, C12:0-C14:0 and 32%, w/w, unsaturated). The fatty acid distributions of the TLA-1,3 and CRU-NS treated samples were similar to untreated milk fat. The proportion of crystalline fat was smaller and the firmness lower in the PAN-2 treated milk fat samples than in the untreated milk fat at 5°C.