Improving ricotta cheese shelf life using saffron petal extract double nanoemulsions stabilized by plant proteins and Lepidium sativum L. gum

This study evaluated the effects of double nanoemulsions of saffron petal extract (DN-SPE), stabilized with soybean (SPI) and pea protein isolates (PPI), alone or combined with Lepidium sativum L. seed gum (LSG) (SL or PL), on the quality and shelf life of ricotta cheese during refrigerated storage (4 ± 0.5 °C). In vitro analyses indicated that adding LSG to protein isolates significantly reduced (p < 0.05) droplet size and enhanced encapsulation efficiency, antioxidant activity, and zeta potential. SPI-LSG nanoemulsions exhibited strong antioxidant activity over time. Encapsulation improved antibacterial efficacy against Staphylococcus aureus, with no significant effect on Escherichia coli. Microscopy showed good encapsulation and particle distribution. SPI-LSG was the most stable formulation and had better thermal stability. The incorporation level of DN-SPE into ricotta cheese (1% w/w) was selected based on preliminary formulation optimization experiments evaluating physicochemical stability, antioxidant performance, and sensory acceptability of the cheese matrix. Treatments mitigated alterations in physicochemical attributes, suppressed microbial growth, and preserved sensory quality. Rheological analysis showed shear-thinning, gel-like behavior in all samples, while DN-SPEs significantly increased apparent viscosity, loss modulus, and storage modulus (p < 0.05). Cheese containing DN-SPE-PL exhibited the greatest rheological parameters and enhanced hardness, gumminess, and chewiness. Overall, DN-SPE emulsions containing of PL or SL provided strong antioxidant and antimicrobial effects, improved the physicochemical and sensory quality of ricotta cheese, and demonstrated potential to extend its short refrigerated shelf life within the 14-day storage period.