Meanwhile scientists at the University of Alberta in Canada found that encasing vitamin D within nanoparticles made from pea protein also increased absorption of the vitamin.
McClements’ own research, meanwhile, has shown that swallowing tablets of beta carotenoid – the precursor to vitamin A – with an emulsion of nano-sized fat globules, known as liposomes can boost the supplement’s “bioavailability” – the amount of vitamin that is absorbed into the blood – by 20%. Good sources of carotenoids include brightly coloured fruits and vegetables such as carrots, broccoli, leafy greens and tomatoes. In one study, McClements asked people to eat a salad either with or without the nanoparticles. The salad contained 50g of baby spinach, 50g of romaine lettuce, 70g of shredded carrots and 90g of cherry tomatoes.
“If you gave them the salad alone, very little carotenoids actually went into the bloodstream because without any fat the vitamins don’t get dissolved in your gastrointestinal fluids,” says McClements.”But then if we fed them the salad with a kind of salad dressing that had very, very tiny fat droplets in, that really increased the amount of carotenoids that got absorbed in the bloodstream.”
The power of seasoning
And this is where the black pepper comes in. When McClements and his team added black pepper to the salad and dressing, it boosted the absorption even more.
Cells in the lining of the intestine often have transporters that can kick out nutrients that have been absorbed, passing them back into the gastrointestinal tract. However a chemical in black pepper blocks these transporters, allowing more vitamin or carotenoids to be absorbed into your bloodstream.
