Emulsion Stability and Rheological Properties of Emulsions Prepared with Ozonized Hazelnut Oil

In this study, physical and rheological characteristics of the emulsion stabilized with whey protein isolate (WPI) at a concentration of 0.25% (w/w) and containing ozone applicated hazelnut oil (OHO) were studied. The hazelnut oil was subjected to ozone gas exposure for durations of 1, 5, 30, 60, 180, and 360 min. The emulsions made with both control (HO) and OHO were analysed to assess emulsion properties. It was observed that as the duration of ozone application increased, the emulsion activity index (EAI) experienced a decrease. Specifically, ozone applications of 30, 60, and 180 min significantly reduced emulsion stability index (ESI). The creaming ratio of emulsions formulated with OHO for durations of 1, 5, 30, 60, and 180 min were found to be 23%, 20%, 18%, 16%, and 44%, respectively. Optical microscopy revealed that significant flocculated droplet formed in emulsions including OHO. The longer time the ozone application resulted that the emulsions exhibited more solid-like behaviour. Furthermore, differential scanning calorimeter (DSC) was utilized to assess the changes in the melting and cooling profiles of hazelnut oil after being applicated with ozone. An increase in ozone application duration led to the melting peaks broadening and shifting towards lower temperatures. Also, ozone application caused that the sharp exothermic crystallization shifted towards lower temperatures and become broader and less pronounced as the duration of the application increased.