What is lutein?
Lutein is a naturally derived carotenoid that is used both as a colour and in food supplements. This particular ingredient is a 10% preparation and derived from marigold flowers. Lutein is a xanthophyll; xanthophylls are yellow pigments that are part of the carotenoid group; they are similar to carotenes in structure; however, they contain oxygen atoms, making them more polar than carotenes. Lutein is found in the leaves of many plants, used by the plants for the absorption of UV-(blue) light, thus protecting the plant against harmful UV rays.
Lutein as a food supplement
Lutein can often be found in food supplements designed for the promotion of eye health, although there are no authorised EFSA health claims to support this, there are many health claims that have been submitted relating to the maintenance of vision, protection against oxidative damage, and protection of skin that are on hold. Vitamin A is a good ingredient to pair with lutein because it has authorised health claims, including the claim: 'Vitamin A contributes to the maintenance of normal skin' and 'Vitamin A contributes to the maintenance of normal vision'. Although lutein is a carotenoid, it does not have any vitamin A activity. Lutein is similar to another xanthophyll called zeaxanthin, so it is often found in similar formulations. Lutein is isomeric with zeaxanthin, meaning they share the same structure, with the exemption of the placement of one double bond.
Lutein is concentrated in the macular of the eye, although the precise functional role of retinal lutein is not fully understood.
Lutein as a colour
Lutein is an approved additive and goes by the following e number: E 161 b
The main colouring principle consists of carotenoids of which lutein and its fatty acid esters account for the major part. Variable amounts of carotenes will also be present. Lutein may contain fats, oils and waxes naturally occurring in the plant material.
Although generally associated with a yellow colour, lutein is a dark orange-red-brown in concentrated amounts
Lutein also goes by the following synonyms: Mixed Carotenoids; Xanthophylls
To see conditions of use, depending on the type of product you are using it in, see Regulation 1333/2008. Lutein is categorised under Group III (colours with combined maximum limit) so you may need to take into account other colours you are using in combination with lutein.
Physical characteristics of lutein
Lutein is a lipophilic molecule, meaning that it is fat soluble, therefore emulsifiers may be required in formulations that require the ingredient to be dispersed into water.
High temperatures promote the degradation of lutein, as does continuous exposure to light. The distinctive light-absorbing properties are due to the presence of the long chromophore of conjugated double bonds (polyene chain); as this polyene chain is susceptible to oxidative degradation by heat or light, it has been proposed and demonstrated by studies that that ascorbic acid (vitamin C) can slow the degradation of lutein. Lutein is also chemically unstable in acids.
Safety/toxicity of lutein
The EFSA opinion on the safety of lutein as a food additive can be found here: https://www.efsa.europa.eu/en/efsajournal/pub/1678
The EFSA opinion on the safety, bioavailability and suitability of lutein for the particular nutritional use by infants and young children can be found here: https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2008.823
Certain member states might have their own limits, for example, Denmark has set a maximum daily dose of 10mg/100ml for fortified beverages. In food supplements, Belgium, Croatia and Denmark have set a maximum daily dose of 20mg. It is important to check with local legislation when choosing a dosage.