Analytical control of nanodelivery lipid-based systems for encapsulation of nutraceuticals: Achievements and challenges

Background: Nutraceuticals are food ingredients that provide benefits, since they are considered to prevent chronic diseases and help improving health. However, utilization of these bioactive compounds in food industry is currently limited because of their poor water solubility, low bioavailability, pH sensitivity and easy degradation in aggressive medium such as the gastric environment. As a solution to these problems several nanotechnological approaches have arisen, like different nanoencapsulation and/or nanodelivery systems to enhance the therapeutic efficacy of nutraceuticals. Scope and approach: The review presents an overview about the state of art relative to nanoencapsulation approaches designed to deliver nutraceutical lipophilic substances in food field, also focusing those nowadays employed techniques to reliably characterize these nanostructured organic materials (NOMs), mainly microscopic and spectroscopic ones with illustrative examples about their application. Lastly, trends and main issues still to solve in the next future are identified and addressed. Key finding and conclusion: Nanoemulsions, nanoliposomes, nanomicelles, solid lipid nanoparticles and nanostructured lipid carriers have been found as already established nanoencapsulation lipophilic systems, although next generation nanocarriers are gaining attention recently. To characterize these nanostructured organic materials, well established tools like microscopic and spectroscopic techniques are already applied in order to assess their associated risks. A critical overview about current limitations, research gaps, industrial and societal applicability and how to face the main challenges relative to sampling and separation techniques for complex matrix like food, the need for reference materials and validated methods and the lack of a single international regulatory framework are aspects especially discussed.