Selective enrichment of dairy phospholipids in a buttermilk substrate through investigation of enzymatic hydrolysis of milk proteins in conjunction with ultrafiltration

Abstract

Extensive enzymatic hydrolysis of milk proteins in reconstituted buttermilk powder was combined with ultrafiltration to generate a phospholipid (PL) enriched fraction with maximum permeation of hydrolysed peptides. Buttermilk, naturally high in PLs, is the ideal substrate for enrichment of these bio- and techno-functionally active compounds. A 7.8 fold increase in PL was achieved in the 50 kDa retentate; 6.16 ± 0.02% total PL compared with 0.79 ± 0.01% in the starting substrate, an increase considerably greater than previously reported. Total lipid content (% dry matter) increased 6.3 fold in the retentate, 43.43 ± 0.61%, from the starting substrate, 6.84 ± 0.17%. This combined strategic approach enabled maximum enrichment of PLs with no transmission of lipid material into the permeate, 0.09 ± 0.02% total lipid, and non-detectable levels of PLs recovered in the permeate, 0.00 ± 0.01% total PL.