Study findings point to an encapsulation efficiency of the carotenoid-rich extract of around 56% with the formed spheroids measuring between 2–30 micrometres (μm).
“We successfully encapsulated sea buckthorn extract by coacervation and freeze drying, using whey proteins and gum acacia, obtaining powder with possible health-promoting properties to be incorporated into hydrophobic matrices,” said the study team based at Dunarea de Jos University of Galati in Romania.
“Both the extract and the microencapsulated powder showed a significant antioxidant activity.”
The use of highly functional carotenoids from different sources is currently limited in the nutritional and functional food space due to their poor water-solubility and low thermal stability.
β-carotene for example is highly prone to chemical degradation during processing and storage due to various environmental effects, such as common thermal stress
Encapsulation is used and recommended for sensitive compounds such as liposoluble vitamins, polyunsaturated fatty acids and enzymes for these very reasons.
Applications such as B vitamins for flavour masking chewable tablets, nutrients for sports nutrition bars and powdered sports beverages with enough viscosity to suspend the particles are examples of microencapsulation use.
Prominent firms active in this space include GELITA, which use collagen peptides to microencapsulate vitamins or other water insoluble micronutrients.
Capsugel build on the microencapsulation theme with a its dual cap offering, a product that combines a pre-filled inner capsule with an outer liquid-filled capsule that allows two incompatible ingredients to be administered as a dosage form to solve stability issues.
Experimental details
In the study, carotenoids from sea buckthorn extract were encapsulated within WPI and acacia gum structures by emulsion and coacervation.
The obtained powders were then analysed for total carotenoid content and encapsulation efficiency.
The microstructures of the particles were also determined using confocal scanning laser, whereas Fourier transform infrared spectroscopy (FT-IR) was used to study the changes in the secondary structure of whey proteins.
Lastly, the functionality of the powder was analysed in terms of the antioxidant activity and colour.
“The total carotenoid content in powder was 2.82 milligram/gram dry weight (mg/g DW), with an antioxidant activity of 548.00 μmol Trolox/g DW,” the study stated.
“FT-IR analysis indicate some degree of aggregation. As the modifications are not significant, protein structure in sea buckthorn extract-whey protein isolate could be considered successfully renaturated.”
Sea buckthorn research
Microencapsulation of the bioactive compounds extracted from sea buckthorn seed oil was the focus of a study that used the hydrolysed starch and maltodextrin as encapsulating materials and spray drying as the encapsulation method.
This study concluded that the relative humidity is of crucial importance when evaluating the protection efficiency of starch-based matrices against oxidation.
In another study, furcellaran beads were used as an encapsulation material for β-carotene from sea buckthorn juice by ionotropic gelation.
The authors found an encapsulation efficiency of β-carotene of 97% and concluded that factors such as the nature of the cation, the polymer and cation concentration, and the proportion of volumes of the outer to the inner phase may influence the size and firmness of furcellaran beads.
Source: Journal of Food Engineering
Published online ahead of print: doi.org/10.1016/j.jfoodeng.2017.09.015
“Valorizations of carotenoids from sea buckthorn extract by microencapsulation and formulation of value-added food products.”
Authors: Nicoleta Stănciuc et al.