Release Properties and Stability of Double W₁/O/W₂ Emulsions Containing Pumpkin Seed Oil

Abstract

The double Water-in-Oil-in-Water emulsions containing a mixture of pumpkin seed and sunflower oil were prepared with polyglycerol polyricinoleate (PGPR) as a hydrophobic emulsifier and different hydrophilic emulsifiers, whereby Tween 20 showed the best stabilization effects. Two different stabilization methodologies of the Water-in-Oil emulsions, (1) stabilization against molecular diffusion degradation (Oswald ripening) by electrolyte (NaCl) addition and (2) gelling of internal water droplets using alginate to form gel phase were employed. Emulsion with co-stabilizer was more stable during storage and heating/freezing treatment than Gel-in-Oil emulsions.Glucose was introduced as a thickening agent in the external water phase. The regulation of the osmotic pressures between the water compartments by glucose addition to the external water phase can be employed to modulate the release behavior of encapsulated material and improve the droplet stability. Also, simple correlation was proposed to predict the release fraction of the salt toward the external water phase.

Development of W/O emulsion for encapsulation of “Pitanga” (Eugenia uniflora L.) leaf hydroethanolic extract: droplet size, physical stability and rheology

“…Its viscosity was calculated (R 2 > 0.99) as 104.6 ± 0.6 mPa.s. This value was higher than that of pure water (~1 mPa.s) and even that of soybean oil (~60 mPa.s) at 25 °C (Ilić et al, 2017), because the droplets contributed to increasing the viscosity condition at 20 and 40 °C, a significant difference (p<0.05) was observed at 60 ºC: 3 g PGPR/100 g oil produced a more stable 20/80 W/O emulsion (Figure 4). And, this can be important for eventual application of this emulsion on thermal processed food, for instance.…”

“…Overall, iIs were correlated with D 3,2 , but it was significant only for iI determined at 60 ºC: iI= 7.6 x 10 -3 D 3,2 + 0.026, R 2 = 0.81. Moreover, the high stability of W/O emulsions can be also associated to two factors: the viscosity of the lipid phase (and consequently, the high viscosity of the whole emulsion, as can be seen in 3.1.4) and the use of PGPR as emulsifier (Dickinson, 2011;Ilić et al, 2017;Tepsongkroh et al, 2015). According to the polarity of the phases leading to increased solubility between them or b) penetrating the interfacial film as a surfactant causing increased flexibility of the interface.…”

Impact of the encapsulated salt characteristics on its release from multiple W/O/W emulsions

“…Apart the fact that they can constitute the encapsulated compound, their presence is essential for the stability of W/O emulsions in order to relieve the problem of Ostwald ripening (Ili c et al, 2017;Koroleva & Yurtov, 2003;Wankhede, Sharma, Hussain, & Bijoy Singh, 2020). However, no detailed studies related to investigation of the impact of the nature and the structure/properties of the encapsulated salt on the stability of the W/O/W double emulsions and their encapsulation efficiency over time, have been performed.…”

Determination of Formulation Conditions Allowing Double Emulsions Stabilized by PGPR and Sodium Caseinate to Be Used as Capsules

“…34 This strategy is very efficient to reduce or stop ripening. Addition of either a gelling agent, in the inner W 1 water phase, 26 or a thickener in the outer W 2 water phase 35−37 have also been proposed without warranting successful stability. Complexion agents in W 1 can be added, e.g., caseinate for Ca 2+ , to increase the size of the encapsulated species and slow down the ripening.…”