Valorisation of lipid-enriched whey protein-based ingredients from dairy processing side-streams

Whey protein isolate (WPI) production generates a considerable amount of a lipid-enriched side-stream, which has to be processed separately and finds use mainly in low-value applications (e.g., animal feed). Although this ingredient is currently underused, it contains substantial quantities of individual valuable nutrients (e.g., lactose, milk minerals, phospholipids (PL) and specific fat globule membrane proteins), in addition to the usual major (e.g., β-lactoglobulin and α-lactalbumin) and minor (e.g., lactoferrin) whey proteins. Previous studies have shown that milk PL originated from the milk fat globule membrane (MFGM) have good bioactive properties and beneficial health effects (e.g., lowering blood cholesterol levels), in addition to attractive techno-functional properties (e.g., emulsifying activity and heat stability enhancement). Currently, the commercially available phospholipid-enriched products are predominantly extracted from buttermilk; besides being a cumbersome process, it also requires a butter production line. Whereas it would be more advantageous, sustainable and economically viable to use this whey-based low-value lipid-enriched by-product, as an alternative source of MFGM-derived material, namely high-value nutritional PL. Preliminary results have shown that this co-product has a significant content of PL. In fact, higher when compared with a commercial buttermilk product, especially in phosphatidylinositol, phosphatidylethanolamine and sphingomyelin. Moreover, milk PL offer higher oxidative stability, essential amino-acids and a non-GMO product recognition, when compared to plant derived lecithin. Therefore, dairy phospholipid-enriched materials should be considered as valuable ingredients for incorporation and manufacturing of new nutraceutical and functional foods, such as e.g., infant formula, sports and elderly nutrition.