Stability of zeaxanthin/lutein in yolk oil obtained from microalgae-supplemented egg under various storage conditions

A lutein and zeaxanthin enriched extra virgin olive oil as a potential nutraceutical agent: A pilot study

Xanthophylls lutein and zeaxanthin are carotenoids with important antioxidant capacities and relevant roles against the prevention of eye diseases. In this study a valorization of non-commercial spinach to obtain lutein and zeaxanthin as raw materials to develop nutraceuticals was carried out. Three oil matrixes were analyzed: extra virgin olive oil (EVOO), lutein and zeaxanthin enriched EVOO (EVOO+LZ), and EVOO enriched with 25 % of EVOO+LZ (namely EVOO+D) to evaluate their biological potential as antioxidants. Urinary antioxidant total capacity, and circulatory blood levels of lutein and zeaxanthin were determined (in vivo analysis). Also, a simulation of gastrointestinal simulation (in vitro analysis) was performed. The results showed an increase in the circulatory levels of lutein-zeaxanthin after the ingestion of EVOO+LZ during 45 and 60 days, and an increase in the urinary antioxidant levels after the intake of EVOO+LZ and EVOO+D. In vitro assay revealed that both xanthophylls showed bioavailability to be assimilated in the intestinal tract. Therefore, these EVOO enriched with lutein-zeaxanthin might be considered as powerful antioxidant tools with potential properties in the management/prevention of eye diseases.

Non-covalent complexes of lutein/zeaxanthin and whey protein isolate formed at different pH levels: Binding interactions, storage stabilities, and bioaccessibilities

Lutein (Lut) and zeaxanthin (Zx) are promising healthy food ingredients; however, the low solubilities, stabilities, and bioavailabilities limit their applications in the food and beverage industries. A protein-based complex represents an efficient protective carrier for hydrophobic ligands, and its ligand-binding properties are influenced by the formulation conditions, particularly the pH level. This study explored the effects of various pH values (2.5-9.5) on the characteristics of whey protein isolate (WPI)-Lut/Zx complexes using multiple spectroscopic techniques, including ultraviolet-visible (UV-Vis), fluorescence, and Fourier transform infrared (FTIR) spectroscopies and dynamic light scattering (DLS). UV-Vis and DLS spectra revealed that Lut/Zx were present as H-aggregates in aqueous solutions, whereas WPI occurred as nanoparticles. The produced WPI-Lut/Zx complexes exhibited binding constants of 104-105 M-1, which gradually increased with increasing pH from 2.5 to 9.5. FTIR spectra demonstrated that pH variations and Lut/Zx addition caused detectable changes in the secondary WPI structure. Moreover, the WPI-Lut/Zx complexes effectively improved the physicochemical stabilities and antioxidant activities of Lut/Zx aggregates during long-term storage and achieved bioaccessibilities above 70% in a simulated gastrointestinal digestion process. The comprehensive data obtained in this study offer a basis for formulating strategies that can be potentially used in developing commercially available WPI complex-based xanthophyll-rich foods.

Deposition and enrichment of carotenoids in livestock products: An overview

A wide range of research has illustrated that carotenoids play a key role in human health through their versatile beneficial biological functions. Traditionally, the majority dietary sources of carotenoids for humans are obtained from vegetables and fruits, however, the contribution of animal-derived foods has attracted more interest in recent years. Livestock products such as eggs, meat, and milk have been considered as the appropriate and unique carriers for the deposition of carotenoids. In addition, with the enrichment of carotenoids, the nutritional quality of these animal-origin foods would be improved as well as the economic value. Here, we offer an overview covering aspects including the physicochemical properties of carotenoids, the situation of carotenoids fortified in livestock products, and the pathways that lead to the deposition of carotenoids in livestock products. The summary of these important nutrients in livestock products will provide references for animal husbandry and human health.

In-vitro bio-accessibility and antioxidant activity of commercial standard and enriched whole egg compounds influenced by production and domestic cooking practices

Commercial whole eggs can be enriched to deliver health-beneficial compounds such as lutein and polyunsaturated fatty acids (PUFA). The combined effect of domestic cooking and gastrointestinal (GI) digestion on enriched egg bio-accessibility and biological activity must be fully elucidated. Thus, this study determines how the combined factors modulate whole egg bio-accessibility and antioxidant activity. Eggs from local supermarkets were cooked and subjected to in vitro GI digestion. The eggs and hydrolysates were characterized for their degree of hydrolysis (DH), carotenoid, PUFA, peptide content, and antioxidant activity. The cooking and digestion influence the DH and carotenoids, whereas PUFA and peptide contents remain unaffected. There was no difference in the antioxidant capacity between the different types of eggs. This study introduces a holistic approach to understanding how production and domestic cooking conditions modulate the bio-accessibility and bioactivity of eggs, which could be used to maximize the health benefits of eggs to consumers.