Lutein extraction by microemulsion technique: Evaluation of stability versus thermal processing and environmental stresses

Stability protection of lutein emulsions by utilizing a functional conjugate of collagen and Lycium barbarum L. leaf flavonoid

Lutein exhibits excellent functional activity making it useful in many fields. Nevertheless, its use is limited by its physical and chemical instability. Here, collagen and Lycium barbarum L. leaf flavonoids (LBLF) were used as emulsifiers, their structures were characterized, the properties of the complexes were evaluated, and their stabilizing effects on lutein emulsions were explored. According to the results, the encapsulation rate of the complex of collagen-LBLF was (68.67 ± 1.43) % and the drug loading was (6.92 ± 0.13) %. Collagen compounded LBLF with a changed structure and morphology, resulting in improved antioxidant capacity, better foaming and emulsification, and reduced hydrophobicity. In addition, the thiobarbituric acid value of collagen-LBLF stabilized lutein emulsion (0.0012 ± 0.00011) mg/kg was significantly lower than that of collagen stabilized lutein emulsion (0.0021 ± 0.00016)  mg/kg (P < 0.05), indicating that the composite stabilized lutein emulsion obtained higher stability. LBLF contributed a high free radical scavenging effect and inhibited lutein degradation during storage. During simulated digestion, collagen-LBLF effectively stabilized the emulsion and protected lutein from destruction, made it release more slowly, and benefited the bio-accessibility of lutein during the next utilization step. Based on the present study, improved storage and digestion stabilities of lutein wereachievedby the utilization of collagen-LBLF complex, which provides a new method for the preparation and application of composite functional emulsifiers.

Curcumin: Overview of Extraction Methods, Health Benefits, and Encapsulation and Delivery Using Microemulsions and Nanoemulsions

Curcumin is the principal curcuminoid found in the rhizomes of turmeric. Due to its therapeutic action against cancer, depression, diabetes, some bacteria, and oxidative stress, it has been used widely in medicine since ancient times. Due to its low solubility, the human organism cannot completely absorb it. Advanced extraction technologies, followed by encapsulation in microemulsion and nanoemulsion systems, are currently being used to improve bioavailability. This review discusses the different methods available for curcumin extraction from plant material, methods for the identification of curcumin in the resulting extracts, its beneficial effects on human health, and the encapsulation techniques into small colloidal systems that have been used over the past decade to deliver this compound.

Surfactant-Enhanced Extraction of Lutein from Marigold Petals using an Aqueous Two-Phase System

The extraction of lutein from marigold petals using a surfactant-based aqueous two-phase system is reported. In this work, the effectiveness of the hydrophilic-lipophilic balance of surfactants on extraction performance for the extraction of lutein from marigold petal powder was demonstrated using aqueous solutions of a wide range of non-ionic surfactants. The response surface methodology was applied to obtain optimised conditions for maximum extraction of lutein. At the optimised conditions (Temperature = 37.5 °C, S/L = 0.00375, and surfactant amount = 1.5% (v/v)), 12.12 ± 0.16 mg/g of lutein was obtained. Furthermore, the surface morphology of marigold petal powder (MPP) was analysed using SEM micrographs. Significant changes in surface morphology were observed which suggested better access of surfactant solution to the targeted biomolecule implanted in the matrix. Finally, the antioxidant activity of the obtained lutein extract was analysed using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Results suggest that the antioxidant activity of the lutein extract obtained by the surfactant-based system is more than that of the lutein extract obtained by organic solvents. The aforementioned results suggest that the lutein can be extracted using a surfactant-based aqueous two-phase system (ATPS).