Effect of Water Content and Pectin on the Viscoelastic Improvement of Water-in-Canola Oil Emulsions

Abstract

This study aimed to investigate gelation in glycerol monooleate (GMO)-stabilized water-in-canola oil (W/CO) emulsions by increasing water content (20–50 wt.%) and the addition of low methoxyl pectin (LMP) in the aqueous phase. A constant ratio of GMO to water was used to keep a similar droplet size in all emulsions. Hydrogenated soybean oil (7 wt.%) was used to provide network stabilization in the continuous phase. All fresh emulsions with LMP in the aqueous phase formed a stable and self-supported matrix with higher viscosity and gel strength than emulsions without LMP. Emulsion viscosity and gel strength increased with an increase in water content. All emulsions showed gel-like properties (storage moduli (G’) > loss moduli (G’’)) related to the presence of LMP in the aqueous phase and increased water content. Freeze/thaw analysis using a differential scanning calorimeter showed improved stability of the water droplets in the presence of LMP in the aqueous phase. This study demonstrated the presence of LMP in the aqueous phase, its interaction with GMO at the interface, and fat crystals in the continuous phase that could support the water droplets’ aggregation to obtain stable elastic W/CO emulsions that could be used as low-fat table spreads.

Stabilization of liquid water‐in‐oil emulsions by modifying the interfacial interaction of glycerol monooleate with aqueous phase ingredients

“…With the addition of LMP (both concentrations) (Figure 2b), a significant improvement in both CO and MO emulsion stability was observed compared to the emulsions without any additives ( p < 0.05). The effect of pectin on improving W/O emulsion stability has recently been reported for W/CO emulsion‐based low‐fat tablespread by Romero‐Peña and Ghosh (2021). Our initial hypothesis was that the presence of a large number of hydrogen bond‐forming groups in the aqueous phase would provide extensive stability to GMO at the W–O interface.…”

“…Overall, CO and MO‐emulsions with LMP (Figure 5) showed a more expanded water droplet network of smaller water droplets than the emulsions with S, AA, CA, or their mixture (Figures 3 and 4). This could also be related to the interaction between GMO and LMP and interfacial strengthening of water droplets' surfaces leading to the highest emulsion stability (Romero‐Peña & Ghosh, 2021). Such droplet networks could be responsible for increasing emulsion stability against phase separation reported for the emulsions with LMP in Figures 1 and 2.…”

Stabilization of liquid water-in-oil emulsions by modifying the interfacial interaction of glycerol monooleate with aqueous phase ingredients

“…However, the presence of Ca and LMP led to lower emulsion stability, which was due to the interaction of Ca with LMP making it less available to hydrogen bond with interfacial GMO. The effect of pectin on improving W/O emulsion stability has recently been reported for W/CO emulsion-based low-fat tablespread by Romero-Peña and Ghosh (2021).…”