ORIGINAL PAPER Microfluidization as Homogenization Technique in Pea Globulin-Based Emulsions Bonastre Oliete 1 & Francois Potin 1 & Eliane Cases 1 & Rémi Saurel 1 Received: 13 July 2018 /Accepted: 10 March 2019 # Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract The effect of microfluidization pressure (50, 70 and 130 MPa) during emulsification on the properties of native (NP) and soluble thermally aggregated (SA) pea (Pisum sativum L.) globulin-based emulsions at neutral pH was studied. Emulsions were char- acterized by interfacial protein-adsorption capacity, charge, emulsifying and flocculation properties, and creaming stability. NP- and SA-based emulsions were highly flocculated. Floc size decreased when increasing the microfluidization pressure during emulsification. Shear, turbulence, and collisions due to microfluidization induced modifications in the protein/aggregate associ- ation at the O/W interface and decreased the oil droplet size. SA-based emulsions showed higher floc size and smaller oil droplet size and revealed a more effective adsorption of SA at the O/W interface than NP. Creaming stability in NP-based emulsions decreased when increasing microfluidization pressure probably as a consequence of depletion-flocculation phenomena. On the contrary, creaming stability in SA-based emulsions improved when increasing homogenization pressure as a result of the formation of a gel-like network. Microfluidization could be used to modulate the emulsifying properties of pea globulin depend- ing on their initial denaturation state. Keywords Pea globulins . Aggregates . Microfluidization . High dynamic pressure . Emulsifying properties Introduction The efficient use of legume proteins is one of the major con- cerns in food industry (Lan et al. 2019). Among legumes, yellow peas (Pisum sativum L.) have been increasingly exploited in the last two decades to produce protein ingredi- ents for human food. However, pea proteins remain largely underutilized by the food industry as consequence of the in- sufficient structure–function knowledge related to their perfor- mance in food formulation (Karaca et al. 2011). The capacity to stabilize emulsion is one of the most im- portant techno-functional properties of pea proteins for their application in oil-based products (Rangel et al. 2003). Their amphiphilic nature (presence of hydrophobic and hydrophilic groups in the same molecule) permits proteins to act as effec- tive emulsifiers by decreasing the surface tension at the oil in water (O/W) interface. The emulsification process consists of two main mechanisms. First, the application of energy reduces the size of fat globules by mechanical shear, inertial forces and cavitation. Secondly, proteins migrate to the O/W interface and then undergo structural rearrangements to form a protec- tive layer by adsorbing at the surface of oil droplets (Euston 2004). The structural modifications of proteins during the emulsification process affect both the secondary and tertiary structures in such a way that maximizes interactions between hydrophobic segments and lipophilic phase (Dickinson 2010). In consequence, the final properties of pea protein-based emulsions depend on the protein properties (conformation, size, surface hydrophobicity, solubility, flexibility), the envi- ronmental characteristics (protein/oil ratio, pH, ionic strength), and the emulsification process conditions (type of homogenizer, amount of energy, flow profile, temperature, time). A complete review about the current progress in the * Bonastre Oliete bonastre.oliete@u-bourgogne.fr Francois Potin francois.potin@u-bourgogne.fr Eliane Cases eliane.cases@agrosupdijon.fr Rémi Saurel remi.saurel@agrosupdijon.fr 1 AgroSup Dijon, PAM UMR A 02.102, University Bourgogne Franche-Comté, F-21000 Dijon, France Food and Bioprocess Technology https://doi.org/10.1007/s11947-019-02265-3