Small changes for big differences: The challenges and opportunities in nano-delievery

The opportunities to exploit and develop nanotechnologies in the food and nutrition sector has resulted in a large number of patents as researchers and food technologists continue to identify novel ways to deliver or re-invent food products. However, in the pursuit of delivering patentable technologies, concerns over consumer health and safety in the use of nanoparticles in foods is an ongoing challenge, say experts.

While the idea of nano-delivery is fairly well known, the practice of using nano-technologies to better deliver ingredients to consumers is one that has, until now, remained firmly in the clinical space, according to Leatherhead Food Research experts Dr Wayne Morley and Kathy Groves. Speaking to NutraIngredients, Groves said that much of the current innovation in nano-delivery systems is in the pharmaceutical sector, and had not been translated in to the food and nutrition arena.

"It comes down to benefits,"​ suggested Morley - who noted that a lack of consumer acceptance means that the food and nutrition industry are very wary of brining the technology in to the mainstream.

"The whole nanotechnology area is first of all down to the benefits that it brings over non nano-based technologies, and secondly whether those benefits can be communicated effectively to consumers or not,"​ explained Morley.

Indeed, in he noted that the key difference between consumer acceptance of nano-drugs and nano-nutrients is that drugs offer immediate clinical benefits or save lives - and therefore are accepted in life and death situations.

"With food, it's obviously not quite as critical as that,"​ said Morley. "You might be looking for an incremental benefit, in which case maybe that benefit isn't sufficient to outweigh the consumer scepticism or concern about the term."​

Small-scale delivery?​

When it comes to delivering nutrients and functional ingredients more effectively, it seems to make sense that going smaller might be better. Whether it be nano-encapsulations, nano-emulsions, or simply creating an ingredient that is on the nano-scale for inclusion in to a product; there is mounting interest in 'small-scale delivery'.

"The interest in nano is with regard to ingredient functionality through size control mostly, because if an ingredient is smaller, it can be more active and more functional,"​ explained Morley.

"In the case of very expensive ingredients, if the required additional level can be reduced by making the particles very small then there can be a cost advantage too,"​ he explained.

Nano-emulsions​

The Leatherhead expert added that while nano-emulsion technology has started to be used to greater effect for the development of foods with reduced fat, sugar, and salt - there is not as much development being seen using the same technologies for the delivery of functional ingredients and bioactives.

"If you think about double emulsions, and water-oil-water emulsions, which have been used for fat and salt reductions, then it's possible to put water soluble bioactives in the internal water to try and protect them a bit from the environment," ​said Morley.

"There's no reason why that that couldn't work in a nano-emulsion, however whether it is worth it in terms of the benefits it adds against the increase in processing costs is another debate that would need to be had."​

The exception to this, according to Groves, are calcium and iron; both of which have seen interest in terms of nano-delivery - citing Fonterra as a group that had been making waves with nano-calcium in Australia and New Zealand.

Nano-structuring​

Another area of interest, according to Groves, is the nano re-structuring of ingredients, which could open up new avenues for the industry.

"If you could start to re-structure ingredients so that they have slightly different properties, then you open up the ingredients field hugely,"​ she commented.

By altering the structure of an ingredient at the nano-scale it may be possible to create more stable, or more bioavailable, form of an ingredient, for example.

"You're effectively manipulating them so that they are not considered a new or novel ingredient but so that they do have different functionality."​

Unintended consequences​

But altering ingredients on the nano-scale could also come with issues, according to Groves, who suggested that one particular problem with producing nano-scale ingredients could be that it alters the way they interact and move around the human body - with unknown consequences.

"If you take, for example, a fat-soluble vitamin and make it more soluble in water by making it smaller then there have been some questions as to where they might end up in the body. Would they end up in the right place, or would they then end up in a place where they shouldn't be?"​ she questioned.

Groves noted that part of the difficulty in predicting the effects of a nano-ingredients in the body is that nobody really knows enough about the mechanism of action, or the mechanism of digestion, for normal-sized nutrients and vitamins in foods.

"They are not really sure what happens to these nutrients in the digestive process, and where exactly they end up,"​ said Groves. "They are almost certainly nano-sized, in some way, when they are in the stomach anyway - so it's difficult to know what would happen if you started at the nano-scale and whether that would affect where in the body they ended up."​