New omega-3 encapsulation could enhance stability for soft gels
Scientists from the Spanish Council for Scientific Research (CSIC), report in the Journal of Food Science that the technique has wider potential for the development of functional foods.
“The current study demonstrated that electrospinning technology, and in particular the electrospraying process, is a potential new platform for enhanced stabilization by encapsulation of omega-3 PUFA,” wrote the researchers, led by Dr Jose-Maria Lagaron, of the Group for Novel Materials and Nanotechnology at CSIC.
Adding stability
Microencapsulated omega-3 ingredients are already used by the food and dietary supplements industry to prevent oxidation and deal with taste and odour issues associated with fish oils. Previous research to improve encapsulation techniques include a recent study suggesting pollen spores could work as an encapsulator.
Like most polyunsaturated fatty acids (PUFAs), DHA’s (docosahexaenoic acid’s) high level of unsaturation means it is quickly oxidised, resulting in the development of off-flavours in enriched food. The oxidation of PUFAs results in the formation of hydroperoxides, that in turn break down into smaller volatile compounds such as aldehydes, ketones, and alcohols.
Electrosprayed structures have been proposed as a solution in a range of protective applications for bioactive supplements, in particular “as a novel route for the stabilization of bioactive antioxidants”, according to the CSIC researchers.
New methods
The new study assessed the potential for applying the electrospraying technique to prepare ultra-thin zein prolamine capsules containing DHA.Researchers observed that encapsulated of DHA omega-3 fatty acid showed a 2.5-fold reduction in the rate of oxidation, with the most effective concentration of zein found to be at a ratio of 3:1 zein:DHA.
The researchers state that DHA could be encapsulated in ultrathin layers of zein prolamine to delay deteriorative reactions and enhance chemical stability under different environmental conditions.
Potential applications
Commenting independently on the research, Winston Samuels, PhD, President and CEO of Maxx Performance, a company specializing in encapsulation, told NutraIngredients-USA: “Essentially what is being described here is a replacement of the traditional gelatin capsule [of animal origin] with one made from Zein”.
Samuels added that the main application for such a new technology would – for now at least – be in soft gel type supplements, where it could replace gelatine as a vehicle for delivery.
“I don’t know what applications this may be useful for aside from taking a fish oil Zein capsule instead of one that is gelatine based,” said Samuels.
Whilst the researchers claim that the technology may be applied to functional foods, Dr Samuels questioned how the new approach would work in food systems. Samuels added that the new study was a “very good academic exercise, and worthy of additional research to determine how suitable it might be for overall application.”
The promise of new omega-3 stabilisation techniques have seen a recent boost, however it remains to be seen which potential new methods – from zein encapsulation, to pollen microencapsulation, or antioxidant stabilizers – will be the most effective at improving the oxidative stability of omega-3 enriched functional foods.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2010.01678.x
“Stabilization of a Nutraceutical Omega-3 Fatty Acid by Encapsulation in Ultrathin Electrosprayed Zein Prolamine”
Authors: S. Torres-Giner, A. Martinez-Abad, M.J. Ocio, J.M. Lagaron
