Utilization of dairy beta stream to produce phospholipids products by salt precipitation and solvent fractionation

Abstract

AbstractDairy phospholipids (PLs) have unique functional and nutraceutical properties over PLs obtained from other sources that typically lack phosphatidylserine (PS) and sphingomyelin (SM). In this study, an underutilized dairy by‐product, beta stream, was used for the production of enriched dairy PLs products and membrane proteins by solvent extractions. After calcium salt precipitation of the membrane components, various green (i.e., safer or bioderived) solvent systems were evaluated for their capabilities for PLs extraction from the PLs‐protein‐salt precipitate in comparison to the standard Folch extraction (chloroform: methanol, 2:1, v/v). Among the five solvent systems (Folch alternatives) evaluated, the combination of hexane and isopropanol (H:IP, 3:2, v/v) was identified as the best for total lipid and PLs extraction, resulting in a recovery of 74.4% and 65.7% (w/w), respectively. EDTA chelating of the calcium ions was applied to produce a salt‐free membrane protein product. A treatment with 0.2% EDTA was able to significantly reduce the calcium content to 0.20 mg/g protein compared to 58.81 mg/g in the initial calcium‐precipitated MFGM. EDTA chelating of cations also facilitated the extraction of lipids during H:IP (3:2) treatment, which increased the total recovery of total lipid and PLs to 90.7% and 82.5% (w/w), respectively. Overall, this study demonstrates a great potential for the utilization of beta stream and other low‐solids content aqueous dairy by‐products for PLs recovery and further fractionation. Value‐added dairy products (PLs and membrane proteins) can be obtained using green solvents identified in this study, and the process is industrially scalable.