Presentation Title

Impact of protein type and Maillard conjugation on nanoemulsion formation and on stability of emulsions at isoelectric point.

Faculty Mentor

Dr. Gabriel Davidov-Pardo

Start Date

17-11-2018 8:30 AM

End Date

17-11-2018 10:30 AM

Location

CREVELING 10

Session

POSTER 1

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

Nanoemulsions are colloidal systems of nanometric (d<500) oil droplets dispersed in an aqueous phase and have been valued in the food industry for their ability to incorporate lipophilic components into aqueous systems. Due to their amphiphilic nature, biopolymers, especially proteins, can be used to stabilize emulsions. While animal-based proteins have been best established for this purpose, there has been a growing interest in legume-based proteins, due to their sustainability, low cost, functional properties, and allergen-free and vegan attributes. However, protein-based nanoemulsions coagulate in pH ranges near the isoelectric point, limiting their use in food and beverage applications. The goal of this study is to optimize the pH stability of emulsions made with Maillard conjugates (MC) of pea protein (PP) and dextran. PP or caseinate (control) were combined in a 1:1 ratio with a 40 kDa dextran solution, freeze dried, and stored in a climacteric chamber (70% RH, 56oC) for 24 hours to promote Maillard conjugation. Nanoemulsions of medium-chain-triglyceride oil were fabricated using high pressure homogenization and MC of PP or caseinate as surfactants. Laser diffraction was used to measure droplet size distributions at pH=7 and pH=4.6. Caseinate-based nanoemulsions exhibited smaller droplet diameter 0.135 ± 0.016 µm and monomodal size distribution compared with those of PP, which resulted in larger droplets 0.237 ± 0.020 and bimodality. MC of both caseinate and PP effectively prevented droplet flocculation and creaming at pH=4.6, while emulsions made with non-MC proteins showed complete destabilization. At pH=4.6, MC emulsions exhibited droplet diameters of 0.143 ± 0.005 and 1.054 ± 0.281 µm for caseinate and PP, respectively. Droplet diameter at pH=4.6 of emulsions made with non-conjugated proteins were 659 ± 449 and 5.24 ±2.02 µm for caseinate and PP, respectively. Future research will continue to optimize PP-based nanoemulsions and will assess antioxidant potential of protein surfactants.

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Nov 17th, 8:30 AM Nov 17th, 10:30 AM

Impact of protein type and Maillard conjugation on nanoemulsion formation and on stability of emulsions at isoelectric point.

CREVELING 10

Nanoemulsions are colloidal systems of nanometric (d<500) oil droplets dispersed in an aqueous phase and have been valued in the food industry for their ability to incorporate lipophilic components into aqueous systems. Due to their amphiphilic nature, biopolymers, especially proteins, can be used to stabilize emulsions. While animal-based proteins have been best established for this purpose, there has been a growing interest in legume-based proteins, due to their sustainability, low cost, functional properties, and allergen-free and vegan attributes. However, protein-based nanoemulsions coagulate in pH ranges near the isoelectric point, limiting their use in food and beverage applications. The goal of this study is to optimize the pH stability of emulsions made with Maillard conjugates (MC) of pea protein (PP) and dextran. PP or caseinate (control) were combined in a 1:1 ratio with a 40 kDa dextran solution, freeze dried, and stored in a climacteric chamber (70% RH, 56oC) for 24 hours to promote Maillard conjugation. Nanoemulsions of medium-chain-triglyceride oil were fabricated using high pressure homogenization and MC of PP or caseinate as surfactants. Laser diffraction was used to measure droplet size distributions at pH=7 and pH=4.6. Caseinate-based nanoemulsions exhibited smaller droplet diameter 0.135 ± 0.016 µm and monomodal size distribution compared with those of PP, which resulted in larger droplets 0.237 ± 0.020 and bimodality. MC of both caseinate and PP effectively prevented droplet flocculation and creaming at pH=4.6, while emulsions made with non-MC proteins showed complete destabilization. At pH=4.6, MC emulsions exhibited droplet diameters of 0.143 ± 0.005 and 1.054 ± 0.281 µm for caseinate and PP, respectively. Droplet diameter at pH=4.6 of emulsions made with non-conjugated proteins were 659 ± 449 and 5.24 ±2.02 µm for caseinate and PP, respectively. Future research will continue to optimize PP-based nanoemulsions and will assess antioxidant potential of protein surfactants.