"Based on the physicochemical properties of the microencapsulated fish oil, sugar beet pectin must be considered as a novel suitable wall material for microencapsulation of lipophilic food ingredients by spray-drying," wrote Stephan Drusch in the journal Food Hydrocolloids (doi: 10.1016/j.foodhyd.2006.08.007).
Microcapsules are tiny particles that contain an active agent or core material surrounded by a shell or coating, and are now increasingly being used in food ingredients preparation.
Indeed, 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.
One such novel technique could be to use sugar beet pectin as an alternative to milk proteins and gum Arabic for the encapsulation of functional food ingredients, like omega-3 polyunsaturated fatty acids, said Dr. Drusch from the University of Kiel.
Dr. Drusch focussed on the spray-drying technique of microencapsulation since this is the most common technique used in the food industry due to its low costs and ease of application. Sugar beet pectin (provided by CPKelco) was used in concentrations of 1.1 or 2.2 per cent in glucose syrup (C*Dry GL 01934, Cargill) to microencapsulate cold-pressed refined fish oil (supplied by Henry Lamotte GmbH).
Microcapsules with 20 or 50 per cent oil were tested and the physicochemical properties evaluated. Drusch reported that 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.
"Physicochemical parameters like particle morphology, particle size and extractable fat generally reflect a good microencapsulation efficiency and therefore indicate a good oxidative stability," reported the researcher.
Drusch did note however that the quantity of non-encapsulated fat was greater in the 50 per cent oil samples compared to the lower oil content, which suggested that there may be a maximum limit on the amount of oil that can be encapsulated since this non-encapsulated oil is more susceptible to oxidation which may affect the sensory properties of the microcapsules.
The higher cost of the sugar beet pectin compared to gum Arabic does not necessarily make this technique unattractive to the food industry 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.
Further research is needed, said the author, to test the oxidative stability of the microcapsules over time as well as flavour retention for aroma compounds.