Omega-3 fatty acids (α-linolenic acid [ALA]) are essential fatty acids and are majorly restricted to seafood, except for a few vegetable oils (flaxseed and canola). They confer beneficial health effects on some cancers, coronary heart disease, and hormonal and neurological disorders (Ajith & Jayakumar, 2019). However, despite their essential role in human healthand development, their deficiency is quite common in vegetarians and non-seafood eaters. On the contrary, there has been a rapid rise in ω-6 fatty acid-rich oils (sunflower, soybean, and groundnut) consumption, which has been proven to affect the metabolic homeostasis of ɷ-6:ɷ-3 fatty acids, resulting in the shift from 1:1 to 20:1 (Simopolous, 2016). This fatty acid composition alteration corresponds to a significant rise in obesity and overweight. Moreover, the eicosanoid metabolic products from arachidonic acid are formed in higher amounts than those originating from ɷ-3 fatty acids, which leads to the development of atheromas, thrombus, and other allergic and inflammatory disorders, resulting in cell proliferation. As a result of the increased blood viscosity, vasoconstriction, vasospasm, and cell proliferation, a diet high in omega-6 fatty acids transform the physiological state into prothrombotic, proinflammatory, and pro-aggregatory (Simopoulos, 2011).
Flaxseed oil is obtained from the plant of flax (Linumusitatissimim) and contains about 57% ALA of its total fatty acid composition. Its consumption has been proven to have a protective effect against type 2 diabetes (T2D), as in a study, the T2D risk was lowered by 21% (Brostow et al., 2011). In addition, a cohort study conducted by Orchard et al. (2010) observed a 54% lower risk of hip bone fractures with omega-3 fatty acidshigher consumption (1.39 g/day), depicting their protective role against bone fracturing. Despite this, its amalgamation into commercial food products is still challenging due to low oxidative stability, higher rancidity rate, off-flavour, poor storage stability, and toxic peroxides. Thus, for its commercial application, a feasible means of shield must be explored. Simultaneously, introducing a protecting layer surrounding the lipid droplets, encapsulation, has been proven to reduce oils' sensitivity to oxygen. Encapsulation is the process of enclosing, packing, and sealing a solid, liquid, or gaseous (core) item within a secondary, more stable material for protection and controlled release (Sharma et al., 2021). Spray drying is the most prevalent process for encapsulating oils in food. The composition and nature of the wall materials affect/control the encapsulated material's properties because of their interfacial functionality (Sharma et al., 2021). Numerous biopolymers have been utilized as wall material in spray drying, especially hydrocolloids such as gum arabic (GA), exhibiting low viscosity, high solubility, and good emulsification. However, because of supply fluctuations and rising pricing, the researchers are looking for alternate wall materials that may replace them or be used in conjunction with other polymers. Maltodextrin (MD), a hydrolyzed starch, has several advantages like a cheap rate, neutral odor and flavor, low viscosity at high solids, and superior oxidation resistance, but it also hasa limited emulsifying ability. As a result, maltodextrin should be used in conjunction with other surface-active biopolymers such as GA, modified starches, etc. (Akhtar & Dickinson, 2007). Proteins for encapsulation offer an additional advantage as they possess a high emulsification capacity. In addition, proteins are excellent in oxidation protection due to lower oxygen permeability (Charve&Reineccius, 2009). Thus, proteins, carbohydrates, and gums’ blends tend to form more stable and efficient emulsions, therefore, are explored widely. As for reservatrol, the whey protein concentrates (WPC) and GA blend improvedemulsion stability (Shao et al., 2019). A ternary combination of wall materials (WPI/GA/MD) was observed to exhibit higher encapsulation rates, powder yield, and better release when utilized for the encapsulation of basil essential oil (Ozdemir et al., 2021). In addition to selecting the wall materials, the techniques of emulsion formation (rotor-stator, high pressure, membrane systems, and ultrasound) are also very imperative (Mehta et al., 2022). Like rotor-stator leads to large droplets of emulsion and increased uptake of oxygen in the continuous phase, while ultrasonic processing offers several advantages like droplet size reduction, energy efficiency, cheap manufacturing costs, system manipulation simplicity, and greater control over formulation factors (Silva et al., 2015; Khatkar et al., 2018a, b). Recently, only one study by Alcantra et al. (2019) examined ultrasonic treatment influence on chia seed oil microcapsules stability using ternary wall material MD/WPI/GA. However, till now, the studies were conducted with the constant or fixed values of the ternary wall materials. The study explaining the combined effect of ternary wall materials (WPC/MD/GA) levels along with ultrasonication time on ɷ-3 fatty acid-containing oil’microencapsulation has not been carried out to date. Therefore, in the present study, flaxseed oil’ stable microcapsules are structured by evaluating the impact of ternary wall materials and ultrasonication. The stable microcapsules are also characterized for stability and invitro release for designing the efficient delivery system of ɷ-3 fatty acids.