Effect of pH and Pea Protein: Xanthan Gum Ratio on Emulsions with High Oil Content and High Internal Phase Emulsion Formation

Abstract

Electrostatic interaction between protein and polysaccharides could influence structured liquid oil stability when emulsification is used for this purpose. The objective of this work was to structure sunflower oil forming emulsions and High Internal Phase Emulsions (HIPEs) using pea protein (PP) and xanthan gum (XG) as a stabilizer, promoting or not their electrostatic attraction. The 60/40 oil-in-water emulsions were made varying the pH (3, 5, and 7) and PP:XG ratio (4:1, 8:1, and 12:1). To form HIPEs, samples were oven-dried and homogenized. The higher the pH, the smaller the droplet size (Emulsions: 15.60–43.96 µm and HIPEs: 8.74–20.38 µm) and the oil release after 9 weeks of storage at 5 °C and 25 °C (oil loss < 8%). All systems had weak gel-like behavior, however, the values of viscoelastic properties (G′ and G″) increased with the increment of PP:XG ratio. Stable emulsions were obtained at pHs 5 and 7 in all PP:XG ratios, and at pH 3 in the ratio 4:1. Stable HIPEs were obtained at pH 7 in the ratios PP:XG 4:1, 8:1, and 12:1, and at pH 5 at PP:XG ratio 4:1. All these systems presented different characteristics that could be exploited for their application as fat substitutes.

Storage Stability of Conventional and High Internal Phase Emulsions Stabilized Solely by Chickpea Aquafaba

“…The values of G′ and G″ at the LVR also decreased with increased storage. The magnitude of the viscoelastic moduli for G′ LVR was in accordance with the previously reported values for some other food hydrocolloids [ 27 ]. As for the loss-tangent values (tanδ LVR ), which is the ratio between G′ LVR and G″ LVR , all values were in the range of 0.09–0.22, indicating a predominantly elastic behavior.…”

“…The flow consistency index (k) is related to the apparent viscosity of the samples; the more viscous the sample, the higher the k. From our results, the k values were higher in the samples that contained more oil, which means that the HIPE (EΦ75%) was more structured and firmer than the emulsions (EΦ70% and EΦ65%), which can be confirmed by the apparent viscosity results at the shear rates of 5 and 300 per second ( Table 2 ). These results can be related to the droplet size of the samples, as the bigger the droplet size, the lower the surface area available for droplets to interact, which, in turn, leads to lower shear thinning behavior and, consequently, lower viscosity [ 26 , 27 ].…”

Characterization of Physicochemical Properties of Oil-in-Water Emulsions Stabilized by Tremella fuciformis Polysaccharides

“…As shown in Table 2, Pec illustrated the highest K value, followed by TFP, CMC, and GA, which was in agreement with the viscosity results. This could have resulted from the different droplet sizes in various emulsions, where the bigger the droplet size, the less availability of droplets to interact, therefore leading to a low viscosity [33,34]. However, the R 2 of all the emulsions in the Herschel-Bulkley model are higher (Table 3) than that in the Power-Law model, indicating a better fitting effect (R 2 > 0.9).…”

Encapsulation of bioactive compounds of food interest: applications, current advances, challenges, and opportunities.

“…Carbohydrates such as starches, corn syrup solids and maltodextrins are frequently employed as encapsulating agents. These materials exhibit low viscosities at high solids concentrations and good solubility (Da Costa et al, 2012;Madene et al, 2006), due to reduced interfacial properties of these materials are employed with mixtures of proteins or gums ( Jayasundera et al, 2011;Vélez-Erazo et al, 2021). Starch and starch-based ingredients (modified starches, maltodextrins and cyclodextrins) act as carrier agents for flavor encapsulation, fat replacers and emulsion stabilizers (Falcão et al, 2022;Madene et al, 2006).…”