Multiple studies have linked carotenoids to many benefits for the human health, such as obesity prevention, ALS risk reduction, and cancer risk reduction. Demand for carotenoid has grown considerably, pushing some manufacturers to expand their facilities.
But carotenoids are also known for their limited bioavailability “due to their chemical, thermal, and shelf stability toward various processing conditions,” a new report published in Food Chemistry said.
The researchers behind this study, affiliated with Universidad de la Frontera in Temuco, Chile, and the Pacific Agri-Food Research Centre in Canada, studied how they can increase carotenoid bioaccessibility through linseed oil nanoemulsions, enhancing the organic pigment’s physical and oxidative stability.
Materials
For this study, the researchers used astaxanthin oleoresin—a carotenoid found in seafood and yeast—from Acatama Bio Natural Products S.A., and Lycopene—a carotenoid found in tomatoes and strawberries—from PhytoLab GmBH & Co. KG in Germany. The linseed oil was purchased from Terrasol Ltda in Chile.
Three types of emulsions were prepared: Astaxanthin-enriched, lycopene-enriched, and a control. The carotenoid emulsions had a 0.5% mass fraction of the carotenoid with 0.5% linseed oil in distilled water, while the control had a 0.5% mass fraction of Tween 20 (polysorbate) in distilled water with 1% linseed oil.
The mixtures were homogenized and then passed through a high pressure homogenizer. Investigation was done on droplet diameter during various homogenization pressures.
A bioaccessibility boost
An in vitro gastrointestinal tract model was used, stimulating mouth, gastric, and small intestine digestion. “Carotenoid nanoemulsians [under 200 nanometers] were partially (66%) digested and highly bioaccessible (70%),” the researchers wrote.
Nanoemulsion droplets of 100 MPa in diameter were observed to have the fastest release and a lower amount of free fatty acids. The addition of the antioxidant Trolox, obtained from EMD Millipore Corp., increased the oxidative stability of nanoemulsions.
“Nanoemulsions provide an effective and stable system for efficient astaxanthin or lycopene delivery,” the researchers concluded, adding that nanoemulsions in linseed oil can be a solution to increase carotenoid bioavailability in foods, beverages, nutraceuticals, and other agriproducts.
Source: Food Chemistry
First published online, doi:10.1016/j.foodchem.2015.12.004
High carotenoid bioaccessibility through linseed oil nanoemulsions with enhanced physical and oxidative stability
Authors: D. Sotomayer-Gerding, et al.