Carotenoids occur naturally in plants, fruits, flowers and vegetables, and represent important sources of antioxidants and vitamin A for some people. However, food manufacturers have struggled to incorporate them into foods due to worries about stability on the shelf and in the digestive system.
The EU-funded Colorspore project began in 2008, after the discovery that certain Bacillus genus bacteria form carotenoid-rich spores that can survive transit through the stomach into the intestinal tract, where due to its acidic nature carotenoids such as lycopene are destroyed.
Colorspore's international research team found that pigmented spores from Bacillus strains are gastric stable, meaning that they could potentially be used for in functional foods such as yogurts and baked goods.
Two most promising strains
As a leading Colorspore researcher, Prof. Simon Cutting from Royal Holloway, The University of London, has patented a range of bacillus strains, including Bacillus indicus HU36 and Bacillus firmus GB1.
The team decided that these two strains were the most promising for industrial production, and thereafter determined their genome sequences; Cutting told this publication last spring that an increasing number of in vitro and in vivo studies were also establishing bioavailability of the compounds.
A January 10 statement from EU body Cordis (the Community Research and Development Information Service), said that the team had evaluated HU36 and GB1 for safety in animal and laboratory tests and found no cause for concern. Other work found that the stability and antioxidant activity of the purified carotenoids in the presence of iron was superior to well-known carotenoids b-carotene and lycopene.
Explaining the advantages of adding carotenoid-producing bacillus spores to functional food as probiotic ingredients, Cutting told NutraIngredients.com this morning: “At the moment, within humans, carotenoid supplements are destroyed during the first few minutes of consumption.
“You can stick them in the middle of a hamburger and gulp the food down quickly or eat a natural source of carotenoids such as carrots, when they’re not destroyed in real food, but this is hardly ideal.”
Potential in baked foods
Cutting said the project’s final stage, due to end in mid-2011, is analysing the potential of HU36 as probiotic food ingredient in baked foods, adding its spores and and assessing the effects on taste, odour, colour and stability. Colorspore has also researched potential use of strains as food colourants.
“The spores are gastric stable and heat stable, but can only survive in the long-term up to circa 80˚C. When you bake it at, say, 200˚C, it can survive for 4-5 minutes, and many possible applications could see the spores added to baked foods," said Cutting.
For instance, in biscuits, you could use the spores in a cream filling that's injected into the product or in a topping that is heated to a high temperature only briefly. Moreover, contrary to popular belief, the spores don’t germinate and grow in yoghurt.”
Confidentiality agreements prevent Cutting from disclosing too much concerning industry interest in licensing the strains, but he said: “There are a number of firms interested, and we’re talking to the biggies. We're already partnering the biggest food company in the world."
Nestle is one of the nine partners in the project, as outlined on the project website.
However, he added that he thought the carotenoid-producing bacteria would require classification by EFSA (the European Food Safety Authority) as novel foods, despite some evidence of prior use in EU countries.