The use of nanomaterials in novel food and beverage applications
As with all novel developments most companies like to keep things under the radar until ready for product launch. A number of companies have at least hinted that nanotechnology plays a part in their NPD strategy. The German company Aquanova AG uses a polysorbate micelle carrier technology to solubilize a range of poorly soluble ingredients for incorporation into clear beverages. Their product range includes isoflavones, natural colours, antioxidants, vitamins and coenzymes such as CoQ10. Their technology is exemplified in the international patent WO2004002469. These micelle systems have a particle size that typically ranges from around 20 nm to 200 nm.
Creating fine dispersions of poorly soluble natural fat soluble colourings to formulate clear beverage products is one area where the technology has been applied. Casein micelles are being investigated for their ability to carry functional ingredients including Vitamin D2 and for use in clear beverages and sports drinks. International patents have been filed by the Technion Research and Development Foundation Limited, Israel; for example “Casein Micelles for Nanoencapsulation of Hydrophobic Compounds” (patent number WO2007122613).
Nanodispersions of particles of around 100 nm can remain stable for longer than conventional emulsions or dispersions and can form clear pseudo-solutions. These properties have been exploited by companies such as Food Ingredient Solutions Limited (www.foodcolor.eu) who use a protein matrix system to formulate natural colours such as astaxanthin for use in beverages. Compass Foods have developed Habo Monoester P90, a monopalmitate sucrose ester surfactant to prepare micellar dispersions of 20-80 nm particles (http://bit.ly/1emuNNV). They propose the option of using nanocapsules containing antioxidants to stabilize the co-encapsulated natural colours. Incorporating colours into nano- and microcapsules to stabilise them may have an impact on their light scattering properties, as the phenomena of Rayleigh scattering and Mie scattering come into play. This means that additional development work may be required to achieve the desired colour outcome. A number of companies have addressed the challenges of formulating natural flavours and are regularly demonstrating their innovative products at the various global ingredients business exhibitions.
Cyclodextrins have been successfully used to encapsulate a wide range of fat soluble functional ingredients by forming molecular inclusion complexes. Cyclodextrins are a form of modified starch with a ring structure made up of glucose units. The most common ones in routine use comprise 6, 7 or 8 member rings and are termed alpha- beta- and gamma-cyclodextrin (figure 2). They have a small outer diameter of less than 2 nm. These molecules have a polar outer surface allowing them to dissolve quite well in water. Their inner core forms a non-polar cavity into which can fit small fat soluble molecules such as many food flavours, fat soluble vitamins and natural colours such as carotenoids. This enables them to be used to help to solubilise poorly soluble ingredients. The three main forms are now being used more widely in new product development (NPD) as approval for their use as a novel food ingredient proceeds through the US, Japan and Europe.
Figure 2. Simplified diagram of the chemical structure of alpha-, beta- and gamma cyclodextrin.
Cyclodextrins have been utilized by the UK company FlavorActiV Limited for over ten years to stabilise flavours, off-flavours and taints. The resulting powders are used for training sensory panels to recognise positive and negative attributes in products, for improved quality management and process control, in the brewing industry and in the wider food, beverage and water industries.
Cyclodextrins are being adopted in the pharmaceutical industry to improve the delivery and bioactivity of active ingredients and are also being used in food supplements and can be found for example in formulations of CoQ10. Tishcon Corporation in the US has commercialized this type of product with their HydroQSorb® product (http://bit.ly/19qpDLB). The performance of a number of different formulations of complexed CoQ10 has been reported by Higashi et al. (2009).
Cyclodextrins have also been investigated for a number of other applications, such as improving the stability of bitter tasting products containing compounds including flavonols (e.g. quercetin, and myricetin) by Lucas-Abellán et al. (2008); taste masking of ginseng and green tea (Wacker AG information sheet “Masking tastes and odors with CAVAMAX® cyclodextrins” (http://bit.ly/1acC16q). A more general review of polyphenol encapsulation has been recently published by Munin and Edwards-Lévy (2011) that details the range of techniques used to encapsulate these often unstable and unpalatable functional ingredients.
In Part 3 we consider what we might mean by the term "nanostructured materials" and is also where you can find further reading and a list of references.
Craig is a consultant, a flavour enthusiast and an unapologetic analytical chemistry geek.