Food and Drink
Four major reasons for encapsulating ingredients within foods or drinks are:
- Taste masking
- Separating functional ingredients from other components within the product that would otherwise destroy them e.g. moisture or acids
- Anti-oxidant protection
- Enhanced efficiency of delivery of some functional ingredients
A wide range of functional ingredients can be encapsulated, as Sporomex technology can be used for both hydrophic and lypophilic materials. Of particular interest to many food manufacturers is avoidance of objectionable flavours from ingredients such as some vitamins and/or increasing the shelf-life of “healthy” oils such as Omega 3, by encapsulating it within an anti-oxidant shell (see scientific publications).
The Sporomex technology only uses a material (pollen / spores) that is natural, renewable and widely consumed. Pollen / spores are found naturally in foods such as mushrooms, cauliflower and honey, whilst the pollen / spores from Lycopodium clavatum, Chlorella and bee pollen is sold in most health food shops. The processing of the pollen / spores is as is traditionally carried out within the food industry, whilst the encapsulation itself is usually an entirely physical process. An encapsulated oil can take the form of a dry powder, which may make its addition much easier in food and drink processing.
The exine shells are resistant to acids, alkalis and temperatures of up to 250 oC., which means that they remain intact through most food and drink processes. In addition their elasticity enables them to withstand many tons of pressure and so avoid physical damage.
Different sizes of exine shells can be chosen according to the desired application. The larger exines have a large central void to shell ratio, so a 40 ?m Lycopodium shell can produce a dry powder even when containing 4 times its own weight of oil. Chlorella at about 8 ?m on the other hand can only hold about its own weight of oil.
The smaller particles are also less visible within a product and lighter coloured shells are sometimes desired. Sporomex technology can produce very light colours. The tablet below is made of compressed exine shells prepared by a special extraction process.
The extraction procedure can also affect the anti-oxidant properties of the exine shells. This too needs optimising according to use. A product where the oil is present at a similar weight to the exine shells, is normally from a different pollen and extraction procedure from a product where the shells are present at 10% or less of the oil. Large increases in shelf-life can be obtained with both types of products as is illustrated here.
The higher the rancimat reading the more rancid is the oil. Echium oil is known to be very unstable, but by encapsulating it at between 0.5:1 and 5:1 (oil:exine, wt:wt) its shelf –life is dramatically increased. This enables some oils to be used to fortify food products such cereals and health bars etc. Sometimes the other components of the product migrate through the porous shell attacking the oil or other functional ingredient inside. In this case starches or gums can be used to fill the pores and/or coat the inside or outside of the shell. This is also required for more volatile substances such as flavours.
At lower concentrations of about 10% exine shells in oil an increased shelf life can also be obtained.
Click here to view a graph of peroxide value of bottles of oil containing sporopollenin (exine shell) over a 8 week period.
The peroxide value is a measure of rancidity, with values above about 20 being unacceptable. These results show a several times increase in shelf-life is possible. One type of product possible at these lower concentrations is to use the pollen exine to preserve its own oil i.e. hemp exine shells in hemp oil.
By choosing the pollen and extraction method it is even possible to use the shells to “clean” an oil. If the oil is encapsulated within these shells and then pressed out again, the peroxide value is lower on exit than before filling.
A recent exciting study has also shown the possibility of this type of encapsulation increasing the effectiveness of functional ingredients. Fish oil was eaten directly or as an encapsulated powder within yoghurt. Measurements were then taken of the amount of eicosapentanoic acid in the blood at intervals up to 24 hours after ingestion. The results are shown here.
Integration of these curves showed that an order of magnitude more EPA entered the blood following encapsulation than had occurred by just ingesting fish oil.
