High Internal Phase Emulsions Preparation Using Citrus By-Products as Stabilizers

Area of Science:

• Food Science
• Material Science

Background:

• The citrus juice industry generates substantial by-products, primarily citrus pomace (CP).
• Citrus pomace is rich in polysaccharides like cellulose and pectin, offering potential as stabilizers and emulsifiers.
• Valorizing citrus by-products is crucial for sustainability and economic benefit.

Purpose of the Study:

• To investigate the use of unmodified citrus pomace (CP) for creating high internal phase emulsions (HIPEs).
• To explore the synergistic stabilizing effects of pea protein isolate (PPI) with CP in HIPEs.
• To characterize the structure, stability, and properties of CP- and PPI-stabilized HIPEs.

Main Methods:

• Preparation of HIPEs using varying concentrations of CP and PPI.
• Rheological analysis to determine viscoelastic properties (G', G'', apparent viscosity).
• Microscopy (e.g., optical microscopy) to visualize emulsion structure and droplet arrangement.
• Assessment of emulsion color and physical stability.

Main Results:

• All tested emulsions exhibited solid-like viscoelastic behavior (G' > G'').
• Increased concentrations of CP and PPI led to higher elastic modulus (G') and apparent viscosity (η).
• Microscopy revealed polyhedral oil droplets encapsulated by a CP and PPI layer, with enhanced packaging at higher concentrations.
• Emulsion physical stability improved with the addition of PPI.

Conclusions:

• Stable HIPEs can be successfully produced using 1.25% CP and 0.5% PPI.
• Citrus pomace and pea protein isolate show significant potential for stabilizing emulsions.
• These HIPEs are suitable for formulating various food products, including mayonnaises, fillings, and creams.