Pilot scale production of a phospholipid-enriched dairy ingredient by means of an optimised integrated process employing enzymatic hydrolysis, ultrafiltration and super-critical fluid extraction

Abstract

Pilot scale production of a dairy ingredient enriched in phospholipids (PLs) was generated from a buttermilk powder (BMP) substrate utilising a combined process of targeted enzymatic hydrolysis of the innate milk proteins followed by ultrafiltration with a 50 kDa membrane. An 8.5 fold increase in PL was achieved in the 50 kDa retentate (50 R) compared to the BMP, 11.05 ± 0.02% and 1.30 ± 0.00% total PL, respectively. Simultaneously, total lipid content in the retentate increased 8.7 fold with reference to the BMP, 60.07 ± 0.54% and 6.84 ± 0.17% total lipid respectively. Protein reduced to 10.58 ± 0.09% (50 R) from 31.40 ± 0.57% in BMP. Supercritical CO2 fluid extraction (SFE) was employed to generate a purified lipid fraction. SFE with ethanol as a co-solvent yielded a purified lipid extract with enriched PLs level of 56.24 ± 0.07% on a dry matter basis. Industrial relevance PLs have many associated health and nutritional benefits including those related to cognitive development and repair. Generation of an ingredient enriched in dairy PLs would be advantageous from an industrial view to allow fortification of nutritionals, both infant and geriatric, in promoting brain health. The present work demonstrates a novel pilot scale process for the generation of a PL enriched ingredient from a BMP substrate. Utilising a combined process of targeted protein hydrolysis followed by selective removal by ultrafiltration of the smaller molecular weight peptide material, an ingredient with 8.5 fold increase in PL material was achieved. SFE technology was utilised to generate a purified lipid extract with greater PL levels for future applications in biological assays to determine these pathways. The need for investigate and further develop the knowledge relating to the modes of action of these bioactive compounds would be beneficial from a nutritional perspective.