Effect of different incorporation processes of chitosan-based oleogel as a fat substitute on the structural characteristics of vanilla ice cream

Ice cream quality depends on fat content and type, but these fats often contain high levels of derived trans fatty acids and saturated fatty acids, which have been associated with increased risk of cardiovascular disease, systemic inflammation and metabolic disorders. The replacement with oils rich in unsaturated fatty acids has been explored to promote better health outcomes. Oleogels have been studied for this purpose in foods. Chitosan-based oleogels show promise but remain unexplored in ice cream. The objective of this study was to evaluate the best method of incorporating this oleogel as a fat substitute during the processing of vanilla ice cream, aiming at a better ice cream structure. It was investigated the impact of this structured oil as a milk cream substitute on the physical, mechanical and structural properties of vanilla ice cream at different production stages. The oleogel, composed of chitosan-based soybean oil, vanillin and Tween®60, was incorporated at three points before pasteurisation, after pasteurisation and after cooling. The apparent viscosity and microstructure of the aged mix and the fat destabilisation, overrun, melting behaviour, texture profile and microstructure of the ice creams were evaluated. The oleogel incorporation after pasteurisation yielded mixes with apparent viscosity (88.1 mPa.s) and microstructure comparable to the milk cream formulation, and ice creams with similar hardness (19.81 N), melting rate (1.2 g/min) and microstructure as the controls. Thus, the incorporation after pasteurisation method was the optimal strategy for incorporating chitosan-based oleogel in ice cream. This study also revealed that the fat incorporation method had a greater influence on the technological properties of oleogel ice cream than on milk cream ice cream. This study provides valuable information to improve the use of chitosan-based oleogel as a fat substitute in food, especially for the dairy industry.