The search for new super antioxidant carotenoids

Carotenoids are regularly praised for their health benefits. To clarify their beneficial properties, the UMR SQPOV has placed its expertise at the service of industry regarding the characterisation of these compounds, whose antioxidant properties, stability, bioavailability and bioaccessibility have thus been analysed in detail.

Some animal and plant products containing carotenoid pigments.. © INRA, PAILLARD Gérard

Carotenoids are natural pigments with numerous virtues, ranging from protection against cardiovascular diseases to the prevention of certain cancers, as well as delaying skin ageing or protecting sight. They also participate in the benefits of the Mediterranean diet. Widely studied in fruits and vegetables, they can nevertheless be obtained from other sources, and particularly from certain coloured bacteria. In the context of two European projects – COLORSPORE and CARODEL – scientists have been focusing on these bacterial carotenoids of a new type which are highly bioavailable and endowed with super antioxidant properties.

In particular, a team of scientists from the Joint Research Unit for the Safety and Quality of Plant Products (UMR SQPOV) has been working on characterising the properties of carotenoids produced by two marine bacteria, Bacillus firmus HU36 and Bacillus indicus GB1. Using in vitro models to simulate oxidative stress in the digestive tract developed by the Micronutrients: Reactivity & Digestion team, they were able to demonstrate the superior antioxidant activity of these bacterial carotenoids by comparison with more classic carotenoids such as beta-carotene, lycopene or lutein. They also established that this antioxidant ability is optimised in the intestinal compartment, where these carotenoids are vectorised in mixed micelles rather than in an emulsion or liposomes.

Once the antioxidant potential had been clearly characterised, it was important to study the bioaccessibility of these carotenoids. The laboratory benefited from different models to simulate the digestive tract (both static and dynamic) and, thanks to European collaborations, had access to other models such as the SHIME (Simulator of the Human Intestinal Microbial Ecosystem), which models the gastrointestinal tract in five compartments and includes the presence of a human microbiota. Monitoring the carotenoids during digestion thus demonstrated that they were not released by the bacteria in the stomach and intestine, and only weakly in the colon. The knowledge acquired by the team on these carotenoids with particular chemical structures has thus made it possible to advance several hypotheses regarding their confinement within bacterial cells, and to propose means to trigger their release.

Thanks to the different technologies available to both characterise the antioxidant potential of a compound or determine its fate in vitro models of digestion, scientists in the Micronutrients: Reactivity & Digestion team are now able to work at levels of complexity that are increasingly similar to physiological conditions.

The European COST EUROCAROTEN network

A European network to advance carotenoid research and applications in agro-food and health

eurocaroten. © eurocaroten
© eurocaroten

The Micronutrients: Reactivity & Digestion team in the SQPOV is involved in the COST EUROCAROTEN network that was launched in April 2016.  Its aim is to enhance the competitiveness of the European agro-food industry and promote health by coordinating research on carotenoids.
EUROCAROTEN focuses in particular on identifying new sources of carotenoids, studying those which have been considered little to date and determining the beneficial effects of carotenoids and how they could be exploited to promote health and enhance the competitiveness of the European agro-food industry. EUROCAROTEN will gather and articulate a critical mass of European actors to promote the co-operative use of infrastructures, synergistic interactions and the sharing, generation, application and communication of knowledge. This will contribute to strengthening Europe’s research and innovation capacities.
EUROCAROTEN is chaired by Professor Antonio J. Meléndez Martínez at the University of Seville, Spain.
The two principal partners responsible for EUROCAROTEN in France are: