Enhanced oxidative stability of O/W Pickering emulsions based on whey protein nanogels.

Lipid oxidation severely limits the stability of food emulsions. This study aimed to improve the interfacial protection of whey protein emulsions by developing nanogel WPI based O/W Pickering emulsion (GWE). Emulsions stabilised by non-heated WPI (NWE) and heat-treated WPI (HWE) were prepared for comparison. Results showed that GWE offered protection against metal induced lipid oxidation and during accelerated storage at 50 °C for 9 days, with significantly lowest amounts of hydroperoxides (1.30 mM) and MDA (8.8 μM). Headspace GC-MS analysis also confirmed that GWE produced less volatile oxidation products, with less aldehydes, ketones and furans after 9 days accelerated storage. Furthermore, GWE showed the lowest protein lipid co-oxidation products formation rate with midpoints of 4.2 days compared with 3.3 and 2.9 days for NWE and HWE, respectively. It demonstrates that GWE effectively modulates oxidation pathways and reduce protein-lipid co-oxidation in protein-based emulsions.