1150Influence of ultrasound treatment on the emulsifying properties of Tenebrio molitor-based ingredients displaying different protein content

Livia A. Santiago1,2, Lucas S. Queiroz2, Ipek Altay2, Gwenn Pinel2 , Naaman F. N. Silva3,2, Betül Yesiltasfname lname2, Aberham H. Feyissa2 , Rodolphe Marie4, Guilherme M. Tavares1 and Federico Casanova2*

1Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, 13083-862 Campinas, Brazil.
2Food Production Engineering, National Food Institute, Technical University of Denmark, Søltofts Plads, 2800, Kongens Lyngby, Denmark.
3Center of Natural Sciences, Federal University of São Carlos (UFSCar), Buri 18290-000, SP, Brazil.
4Department of Health Technology, Technical University of Denmark, Ørsteds Plads, 2800 Kongens Lyngby, Denmark.

This study investigated the influence of protein extraction steps and ultrasound (US) treatment on the structural and emulsifying properties of Tenebrio molitor protein-based ingredients displaying different protein contents. A mealworm defatted flour (MDF) and a mealworm protein isolate (MPI) were produced through defatting and alkaline solubilization, followed by isoelectric precipitation, respectively. Proximate composition revealed a significant increase in protein concentration from MDF (56.86 ± 0.68 %) to MPI (87.74 ± 3.64 %), although the protein extraction yield decreased from 87.41 % (MDF vs. initial flour) to 13.60 % (MPI vs. MDF). MPI exhibited a smaller particle size, higher solubility, and greater surface hydrophobicity and intrinsic fluorescence than MDF, indicating structural rearrangements that enhanced interfacial activity. Ultrasound (US) treatment induced conformational modifications in protein structure, increasing surface hydrophobicity without altering molecular weight distribution. Emulsions stabilized with MPI displayed smaller droplet sizes, higher ζ-potential values, and superior physical stability compared to MDF-based emulsions. Although US treatment did not affect the macroscopic properties of MPI emulsions, it improved the stability of MDF emulsions, suggesting enhanced interfacial adsorption and droplet stabilization. US treatment did not compromise the emulsifying properties of MPI despite the structural changes induced, while it enhanced the functionality of MDF, highlighting ultrasound as a promising and sustainable approach to improve the techno-functional performance of insect-based protein ingredients.