Structural and Textural Properties of Apple Cheese Fortified with Pomegranate Seed Oil Emulsion Stabilized by Chitosan–Zein Particles

Apple production generates considerable waste, which can be reduced by processing it into apple cheese. However, nutritional losses during processing necessitate the addition of functional ingredients. Pomegranate seed oil, rich in unsaturated fatty acids but prone to oxidation, can be encapsulated to enhance oxidative stability and improve the nutritional value of the product. Chitosan–zein particles were prepared at a 1:10 ratio and used to stabilize oil-in-water emulsions containing 20% and 30% pomegranate seed oil. The 20% oil emulsion showed greater stability and was selected for functional apple cheese production. Three treatments were formulated: control (T1), chitosan–zein emulsion containing 0.2% oil (T2) and chitosan–zein emulsion containing 0.5% oil (T3). Textural properties, including color, hardness, brittleness, adhesiveness, cohesiveness and gumminess, were then evaluated. The Pickering emulsion droplets had an approximate size of 1 µm and exhibited Newtonian flow behavior. SEM images showed that chitosan–zein particles formed compact and cohesive structures during drying. The 20% Pickering emulsion stabilized with chitosan–zein particles demonstrated the lowest creaming after 14 days of storage. Textural analysis (hardness, firmness, adhesiveness, cohesiveness and gumminess) of apple cheese samples containing the pomegranate seed oil emulsion showed no significant difference in hardness between the control and the 0.2% emulsion sample (P > 0.05). The results showed that pomegranate seed oil emulsified with chitosan–zein particles can be used as a stable ingredient in functional apple cheese. Incorporation of the oil in emulsion form at levels up to 0.2% was found to be appropriate for the product formulation.