Encapsulation innovation highlights

With the fear of commodification continuously looming, food manufacturers are turning to microencapsulation technologies as a way of achieving much-needed differentiation and enhancing product value. Tapping into key and emerging consumer trends with innovative techniques is becoming increasingly important for food manufacturers.

Changing consumer trends and tastes are primarily responsible for driving innovation in the microencapsulation market, says market analyst Frost & Sullivan. Since food manufacturers constantly monitor such trends, food ingredients companies are always looking for ways to meet these ever-changing demands, thereby promoting the need for novel microencapsulation technologies.

Sugar beet pectin for omega-3​

University of Kiel researcher Stephan Drusch reported that microencapsulation of oil ingredients, like omega-3, with sugar beet pectin could provide an alternative to more traditional encapsulating agents like milk proteins and gum Arabic.

Drusch reported that, by using the spray-drying technique suitable emulsions could be produced with up to 50 per cent oil and 2.2 per cent sugar beet pectin with median oil droplet sizes less than two micrometres.

The higher cost of the sugar beet pectin compared to gum Arabic does not necessarily make this technique unattractive to the food industry, said Drusch, since the low protein content of gum Arabic means that higher quantities are normally used (between 15 and 25 per cent).

"The low quantities necessary for emulsification lead to similar costs in use compared to other emulsifying wall constituents like gum Arabic,"​ said Drusch.

Source: Food Hydrocolloids​ (doi: 10.1016/j.foodhyd.2006.08.007)

Milk protein nanotubes​

Writing in the journal Trends in Food Science and Technology​, Joanke Graveland-Bikker and Kees de Kruif reported that the ability of the milk protein alpha-lactalbumin to self-assemble into nanotubes could offer the food industry a novel and important ingredient for gelling and encapsulation.

The researchers reported that alpha-lactalbumin can be partially hydrolysed by protease enzymes from Bacillus licheneiformis​. When this partially hydrolysed protein is exposed to calcium ions, the formation of a linear nanotube is triggered.

These nanotubes, said to be the only food protein nanotube, have good stability and can withstand pasteurisation conditions (72 degrees Celsius for 40 seconds) as well as a freeze-drying treatment, they said.

The alpha-lactalbumin nanotubes, with an eight-nanometre cavity, can be formed with open or closed ends, said the researchers, and reported that lipid caps can be used to close the tubes, thereby offering the possibility for controlled release applications.

The properties of the nanotubes are not limited to encapsulation, said Graveland-Bikker and de Kruif, with alpha-lactalbumin nanotubes also showing significant potential for increasing viscosity and in gelation.

Co-author Professor Kees de Kruif told FoodNavigator.com: "We aim at developing a full dairy viscosifier with potentially new structures and textures as the nanotubes show a remarkable rheology. The more so as the gels and dispersions are almost transparent.​

"From as of today there is no application on the market, but there is interest for various food applications and contracts for one or two applications may be signed this fall,"​ he said in October.

Source: Trends in Food Science and Technology​ (Vol. 17, pp. 196-203)

Casein protein offers nano-encapsulation potential​

Researchers from the Israel Institute of Technology in Haifa have reported that the natural ability of the milk protein casein to from nano-sized micelles offers huge potential to nano-encapsulate sensitive ingredients.

The protein casein makes up about 80 per cent of the protein content of cow's milk (30-35 grams per litre) and is found naturally in the form of spherical micelles with diameters ranging from 50 to 500 nanometres. The stability of these micelles during processing also makes them a very attractive nano-encapsulator, indicated the authors.

Indeed, lead researcher for the study, Dr. Yoav Livney, told FoodNavigator.com that the approach is unique. Dr. Livney said that the casein micelles are designed by nature to concentrate, stabilize and deliver nutrients to the newborn.

"It's a natural way to encapsulate and deliver nutrients,"​ he said.

The researchers have applied for a patent for this "unique approach"​, and Dr. Livney confirmed that "industrial companies have already shown interest in commercializing this new technology."​

Source: Food Hydrocolloids​ (on-line ahead of print, 2006, doi: 10.1016/j.foodhyd.2006.09.006)

Corn fibre gum to replace gum arabic​

Innovation from the USDA's Agricultural Research Service reported that a gum produced from corn fibre could offer a viable and profitable alternative to gum arabic as emulsifiers in beverages.

And the applications for corn fibre gum beyond beverages could possibly include encapsulation of essential oils and fatty acids, glossy coatings and biodegradable edible films, and even as a prebiotics, lead researcher Dr. Madhav Yadav from the ARS told FoodNavigator.com.

The gums were prepared by a sequential alkaline extraction and alkaline hydrogen peroxide bleaching technique or an additional alkaline hydrogen peroxide treatment of the alkali treated residue.

While Dr. Yadav could not comment on the price of commercial corn fibre gum, he told FoodNavigator.com that a rough cost estimation by an ARS cost engineer suggested that, based on the assumed price of the raw materials, the cost would be about $2.00 per pound ($4.40 per kg) for a laboratory preparation. This compares favourably with the time market value of gum arabic, that was between $3.00 and $6.00 per pound ($6.60 to $13.20 per kg), said Dr. Yadav.

But while the laboratory results and cost estimations offer significant promise, Dr. Yadav confirmed that the biggest challenge for corn fibre gums remained "being able to produce CFG cost-effectively in a form that will meet the demands of the end user in product applications."​

Source: Food Hydrocolloids​ (doi: 10.1016/j.foodhyd.2006.07.009)