Researchers from Agrotecnio and the University of Lleida (UdL) demonstrate that cloudy apple juice helps preserve curcumin and enhances its bioaccessibility in the body.
Curcumin, the bioactive compound responsible for the characteristic yellow colour of turmeric, is known for its antioxidant, anti-inflammatory and antimicrobial properties. Despite its potential, incorporating curcumin into functional foods—that is, foods designed to provide health benefits beyond basic nutrition—is challenging. Curcumin has low water solubility, degrades easily and only a small fraction is available for body absorption.
A research team from Agrotecnio and the University of Lleida has explored a strategy based on food nanotechnology to overcome these limitations. The study examines the incorporation of curcumin encapsulated in lipid nanoparticles into cloudy apple juice, with the aim of assessing how the food medium influences its stability, digestibility, and bioaccessibility.
The results, published in Food Research International, show that not only the encapsulation technology is important, but also the type of beverage in which these nanoparticles are incorporated, as this influences curcumin preservation and the fraction that becomes bioaccessible after digestion.
Cloudy apple juice, a protective matrix for curcumin
The study shows that cloudy apple juice helps maintain the stability of encapsulated curcumin. After 70 days of storage, samples prepared in apple juice retained a higher amount of the active compound compared to those prepared in water.
This effect may be linked to natural components of the juice, such as pectin and antioxidant compounds, which could help reduce curcumin degradation and enhance its stability.
Solid lipid nanoparticles showed the highest curcumin bioaccessibility
The researchers also analysed different types of lipid nanoparticles formulated with various fats. These nanoparticles act as small “vehicles” designed to protect curcumin from factors such as light, oxygen, or temperature, and modulate its behaviour during digestion.
The results show that the composition of the lipid used has a significant impact on its effectiveness.
Simulated digestion experiments indicate that nanoparticles incorporated into cloudy apple juice allow a greater amount of curcumin to become bioaccessible compared to those dispersed in water.
In this context, formulations based on coconut oil-based solid lipid nanoparticles showed the best performance, with bioaccessibility close to 40%, higher than the other combinations studied.
Implications for functional foods
According to the authors, the study highlights that both the composition of the nanoparticles and the type of beverage in which they are incorporated are key factors in improving the stability and bioaccessibility of bioactive compounds.
The research reinforces the potential of food nanotechnology to deliver lipophilic substances in foods and beverages and suggests that fruit juices such as cloudy apple juice may serve as suitable environments to enhance their stability.
This approach could be applied to other bioactive compounds with similar problems of degradation and low bioaccessibility, supporting the development of new functional foods with improved delivery potential.
More information:
Parsi, A.; Turmo-Ibarz, A.; Salvia-Trujillo, L.; Martín-Belloso, O. Incorporation of curcumin-loaded lipid nanoparticles into a cloudy apple juice: study of the chemical and colloidal stability, in vitro digestibility and bioaccessibility. Food Research International, 2026.
