Enrichment of a fruit-based smoothie beverage with omega-3 fatty acids from microencapsulated chia seed oil

Omega-3 fatty acids are known for their various health benefits. Chia is the richest vegetable source of omega-3 fatty acids. However, its oil is highly susceptible to oxidative deterioration and should be protected for incorporation into food matrices. This work aimed to study the incorporation of different chia oil microcapsules in a powdered beverage, analyzing the effect on the physicochemical characteristics and stability during storage.

Different types of microcapsules were obtained: monolayer microcapsules using sodium caseinate and lactose as wall material, and multilayer microcapsules produced through electrostatic deposition using lecithins, chitosan, and chia mucilage as the first, second, and third layers, respectively. The results demonstrated an efficient enrichment of smoothies, with omega-3 fatty acid values ranging from 24.09% to 42.73%, while the original food matrix powder lacked this component. These powder beverages exhibited low moisture content (≤ 2.91%) and low water activity (≤ 0.39). The aerated, packed density and compressibility assays indicated that adding microcapsules made the powders less dense and compressible. The color of the original powdered beverage was not modified. The dispersibility reflected an acceptable instantaneity, reaching the maximum obscuration after 30 s of stirring. The solubility of all the enriched products was higher than 70%, whereas the pH was ~6.8. The contact angle between the powder and liquid indicated an excellent ability to be reconstituted in water. The analysis of the glass transition temperature showed that the storage temperature (25 °C) was adequate. The peroxide value of all the products was low throughout the storage (≤ 1.63 meq peroxide kg^-1 of oil at 90 days at 25 ± 2 °C), thus maintaining the quality of the microencapsulated chia oil.

The results suggest that incorporating the monolayer and multilayer chia oil microcapsules that were studied could be a viable strategy for enriching smoothies with the omega-3 fatty acids present in chia seed oil. © 2023 Society of Chemical Industry.