Carotenoids are ubiquitous and versatile isoprenoid compounds. The intake of foods rich in these pigments is often associated with health benefits, attributable to the provitamin A activity of some of them and different mechanisms. The importance of carotenoids and their derivatives for the production of foods and health-promotion through the diet is beyond doubt. In the new circular economy paradigm, the recovery of carotenoids in the biorefinery process is highly desirable, for which greener processes and solvents are being advocated for, considering the many studies being conducted at the laboratory scale. This review summarizes information on different extraction technologies (ultrasound, microwaves, pulsed electric fields, pressurized liquid extraction, sub- and supercritical fluid extraction, and enzyme-assisted extraction) and green solvents (ethyl lactate, 2-methyltetrahydrofuran, natural deep eutectic solvents, and ionic liquids), which are potential substitutes for more toxic and less environmentally friendly solvents. Additionally, it discusses the results of the latest studies on the sustainable green extraction of carotenoids. The conclusions drawn from the review indicate that while laboratory results are often promising, the scalability to real industrial scenarios poses a significant challenge. Furthermore, incorporating life cycle assessment analyses is crucial for a comprehensive evaluation of the sustainability of innovative extraction processes compared to industry-standard methods.

Phytoene is a colourless carotenoid widely available from dietary sources and a precursor for the synthesis of other carotenoids. Although present at high concentrations across different tissues, phytoene is largely viewed as not having physiological activity. Here, we utilize the model organism C. elegans to show that phytoene is bioactive and has anti-ageing properties. Supplementation with phytoene protects against oxidative damage and amyloid-β₄₂ proteotoxicity (a major pathology of Alzheimer’s disease), and extends lifespan. We also examine extracts from two microalgae, Chlorella sorokiniana and Dunaliella bardawil. We show that the extracts contain high levels of phytoene, and find that these phytoene-rich extracts have protective effects similar to pure phytoene. Our findings show that phytoene is a bioactive molecule with positive effects on ageing and longevity. Our work also suggests that phytoene-rich microalgae extracts can utilized to produce foods or supplements that promote healthy ageing and prevent the development of chronic age-related diseases.

Extracting bioactives from algae is essential for sustainable solutions aimed at enhancing human health. This study pioneers a multidimensional approach that simultaneously compares ultrasound-assisted carotenoid extraction from spray-dried (SD) and solar-dried (SolD) Spirulina platensis, evaluating both food-grade and emerging green biosolvents, validated through COSMO-SAC predictions and optimized using RSM. The SD sample showed higher carotenoid yields with most solvents, consistent with particle size data indicating less aggregation than SolD. Solvent efficacy varied depending on drying method and carotenoid type; acetone was optimal for zeaxanthin and β-carotene from SD and β-carotene from SolD, while methanol and ethanol were more effective for zeaxanthin in SolD. The green solvent 2-methyltetrahydrofuran (2-MeTHF) demonstrated excellent carotenoid affinity in COSMO-SAC predictions and ranked as the second most effective solvent in the SD sample, underscoring its potential as a sustainable alternative. RSM models using 2-MeTHF (SD) and ethanol (SolD) showed excellent prediction accuracy (R² > 98%). Optimized extraction conditions yielded ~4-fold higher total carotenoid recovery compared to non-optimized conditions. Combining computational tools and experiments offers an effective strategy to optimize sustainable extraction of health-promoting carotenoids from Spirulina.

The identification of new functional food constituents is a priority to improve the prognosis and prevention of colorectal cancer (CRC). In this study, several bacterial and algal phytoene-enriched extracts were obtained, and their potential activity against oxidative damage and their ability to inhibit proliferation and cell migration in several human colon-adenocarcinoma-derived cell lines were assessed. The main conclusions indicate that total extracts of Sphingomonas echinoides and Chlorella sorokiniana exhibited the highest protective effect against oxidative damage. All extracts enhanced the activity of detoxifying enzymes, particularly importantly the increase of NAD(P)H:quinone oxidoreductase activity, which reached a value 40% higher than that of untreated control cells upon exposure to Escherichia coli extracts. Staphylococcus haemolyticus and transgenic E. coli extracts significantly arrested the migration capacity of both cell lines, while S. haemolyticus and C. sorokiniana extracts inhibited cell proliferation by 15 to 20% compared to untreated cells. These results point to these extracts as potential antioxidant complements able to protect cells against oxidative damage and with a moderate ability to inhibit the proliferation and migration of CRC tumor cells, paving the way to design functional foods or probiotic formulations with preventive properties against oxidative stress-related diseases, such as cancer, or as starting point for purifying anticancer compounds.

The role of foods is shifting from focusing on the provision of energy and basic nutrients to also include bioactive compounds that prevent the development of chronic age-related diseases. Mi-croalgae offer a source of nutritional compounds with important health effects, and have the po-tential for production of health-promoting products, without increasing agricultural land use and negatively impacting the environment. Here we investigate the health effects of microalgal ex-tracts with high levels of the colourless carotenoid phytoene. Phytoene is widely available from dietary sources and can be detected across different tissues in the human body. However, it is usually regarded as a precursor for the synthesis of other carotenoids, rather than a bioactive molecule. We utilised the model organism C. elegans to show that phytoene-rich extracts from Chlorella sorokiniana and Dunaliella bardawil have anti-ageing properties. The extracts protect against oxidative damage and amyloid-β42 proteotoxicity (a major pathology of Alzheimer's disease), and extends lifespan. We show that pure phytoene also has these anti-ageing effects, suggesting that phytoene is a bioactive molecule with positive effects on ageing and longevity.