Preparation and characterisation of a milk polar lipids enriched ingredient from fresh industrial liquid butter serum: Combination of physico-chemical modifications and technological treatments

Milk polar lipids (PLs) are poorly utilised as ingredients for human consumption, despite their interesting nutritional and functional properties. The objective of this study was to valorise by-products by developing a technological process able to provide a milk PL-enriched ingredient from industrial fresh liquid butter serum. The process comprised the following successive steps: skimming, heat treatment, acid precipitation of caseins, concentration and purification of whey butter serum by ultrafiltration and diafiltration. The proposed process yields a recovery of 62% of PLs present in the initial butter serum. The final ingredient contained 31.5%, 26% and 34% of PLs, proteins and triacylglycerols (on a dry matter basis). The identified proteins were caseins, whey proteins and proteins from the milk fat globule membrane. This process will allow the preparation of a milk PL-rich ingredient for food applications.