Recently, there has been a strong interest in nanoparticles (NPs) and their use in a wide range of food applications due to their possession of a set of unique physical and chemical properties. In this work, the nanoformulation was synthesized by coating Fe Ion and Zahdi date pit powder (ZDP) by whey protein. This nanosystem was functionalized by folic acid (FA) molecules. The physiochemical characteristics of WPI@Fe-ZDP-FA nanocomposite were evaluated and confirmed by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and radical scavenging activity using DPPH methods. These NPs were added to skim milk and yogurt was produced from it. The effects of this addition on the chemical, physical and sensory properties of yogurt were studied during storage at $5^{\circ}$ C for 28 days. The prepared nanocomposite was used in proportions of 0.25%, 0.5% and 0.75%, respectively. The chemical tests included measuring the percentage of moisture, protein, carbohydrates, fat, and ash, in addition to the total acidity and pH, while the rheological tests included hardness, cohesion and flexibility. A sensory evaluation of the curd parameters was also performed. The curd treatments to which the nanocomposite was added showed a decrease in the level of moisture over the length of the storage period and an increase in the percentage of protein, carbohydrates and ash compared to the control sample that was without the addition. As for the rheological tests, there was a discrepancy in the results of the treatments when compared to the control treatment, as the addition of 0.25% has higher characteristics than all other treatments, especially in the ability to retain water and spontaneous whey excretion. It was more acceptable in terms that the novel WPI@Fe-ZDP-FA nanoformulation greatly improved the characteristics of texture, taste and flavor in yogurt.

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