Nano-emulsions boost curcumin as health ingredient
spice turmeric its yellow colour, could be enhanced by
encapsulation in nano-emulsions, suggests new research.
The study, published in the journal Food Chemistry, taps into the potential of nano-encapsulation to achieve much-needed differentiation and enhanced product value. Encapsulation, be it on the micro- or nano-scale, is increasingly being used to delay the release of flavours, aromas and bioactive ingredients. The new research looked at the potential of high-speed and high-pressure mixing of oil in water emulsions to protect curcumin and thereby enhance its potential health benefits. Curcumin has increasingly come under the scientific spotlight in recent years, with studies investigating its potential benefits for reducing cholesterol levels, improving cardiovascular health and cancer-fighting abilities. By preparing a model emulsion using medium chain triacylglycerols (MCT) as oil and Tween 20 as emulsifier, researchers from Rutgers University prepared emulsions containing droplets ranging from 618.6 nm to 79.5 nm. According to background information in the article, the majority of ingested curcumin is excreted with only limited uptake into the blood. This is due to the insolubility in water under acidic or neutral conditions. Moreover, the pigment is rapidly metabolised in the intestine, so finding a means to protect curcumin could enhance its bioavailability. "Although curcumin is almost insoluble in water, it is found that one per cent curcumin can be successfully encapsulated in O/W emulsions, suggesting that O/W emulsions have a high capacity to carry curcumin," wrote the researchers. When tested in vivo in mice, the researchers reported that inflammation in the ear of the test animals (mice) would be reduced by 43 and 85 per cent when one per cent curcumin was encapsulated in 618.6 nm and 79.5 nm oil-in-water emulsions. "It should be pointed out here that it is the synergistic effects of both emulsion droplet size and the presence of lipid in the emulsion that provide the optimum anti-inflammation activity of curcumin," wrote the researchers. "Accordingly, high-pressure homogenised curcumin emulsions containing 79.5 nm emulsion droplets exhibit higher anti-inflammation activity than high-speed homogenised curcumin emulsions containing 618.6 nm emulsion droplets," they concluded. The researchers confirmed that the area was one of ongoing study. They state that evaluation of pharmacokinetics and biodistribution of curcumin encapsulated in the emulsions are underway. According to organisers of the recent Nano and Microtechnologies in the Food & Healthfood Industries conference in Amsterdam, the application of nanotechnology and nanoparticles in food are emerging rapidly. Some analysts predict that nanotechnology will be incorporated into 16.4bn worth of food products by 2010. However enthusiasm over the rate of progress and the possibilities is being tempered by concerns over possible downsides of the science of the miniscule, stated the Institute of Nanotechnology. Source: Food Chemistry (Elsevier) Published on-line ahead of print, doi: 10.1016/j.foodchem.2007.10.086 "Enhancing antiinflammation activity of curcumin through O/W nanoemulsions" Authors: X. Wang, Y. Jiang, Y-W. Wang, M-T. Huang, C-T. Ho, Q. Huang
