Chitosan-Curcumin Nanoformulation to Improve the Physicochemical and Rheological Properties of Yogurt

Nanotechnology has garnered increasing attention in the food industry due to its potential to provide innovative solutions to improve product quality and enhance functional efficiency. One of the major challenges in dairy products is their short shelf life and the deterioration of their quality during storage. This is compounded by curcumin’s limited bioavailability due to its poor solubility and degradation in the acidic environment of the stomach, limiting its intestinal absorption. Therefore, this study aimed to develop a chitosan-curcumin (Cs@CU) nanosystem to protect curcumin during passage through the stomach, enhance its controlled release and intestinal absorption, and improve the quality and shelf-life of yogurt.The nanoparticles were synthesized and characterized by evaluating their encapsulation and loading efficiency, particle size, zeta potential, and morphology using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, the release behavior of curcumin was investigated, and its antioxidant activity was assessed using DPPH and ABTS assays. The results showed the formation of stable spherical nanoparticles with an average size of 62.42 nm and a positive zeta potential (+ 43 mV), indicating high stability and good dispersion efficiency, along with effective control of curcumin release. The nanoparticle formulation was added to skimmed milk at concentrations of 0.5, 1.0, and 1.5 mL/100 mL to produce yogurt. The samples were then stored at 5 °C for 28 days. Analyses included evaluation of the product’s chemical, rheological, and sensory properties. The results showed a clear improvement in the properties of the enriched yogurt. Whey separation decreased to 2 mL/50 mL on day 28, and water retention increased to 76%, with significant improvements in texture and viscosity, particularly at the 0.5 and 1.0 mL/100 mL concentrations. These treatments also achieved the highest sensory acceptance scores, with a 90% rating from the judges for taste, flavor, and homogeneity. The results generally indicate that the Cs@CU nanosystem is a promising strategy for enhancing curcumin’s biostability, improving yogurt quality, and extending its shelf life to 28 days.