Influence of the processing on composition, protein structure and techno-functional properties of mealworm protein concentrates produced by isoelectric precipitation and ultrafiltration/diafiltration

Edible insects represent a great alternative protein source but food neophobia remains the main barrier to consumption. However, the incorporation of insects as protein-rich ingredients, such as protein concentrates, could increase acceptance. In this study, two methods, isoelectric precipitation and ultrafiltration-diafiltration, were applied to produce mealworm protein concentrates, which were compared in terms of composition, protein structure and techno-functional properties. The results showed that the protein content of the isoelectric precipitation concentrate was higher than ultrafiltration-diafiltration (80 versus 72%) but ash (1.91 versus 3.82%) and soluble sugar (1.43 versus 8.22%) contents were lower. Moreover, the protein structure was affected by the processing method, where the ultrafiltration-diafiltration concentrate exhibited a higher surface hydrophobicity (493.5 versus 106.78 a.u) and a lower denaturation temperature (161.32 versus 181.44 °C). Finally, the ultrafiltration-diafiltration concentrate exhibited higher solubility (87 versus 41%) and emulsifying properties at pH 7 compared to the concentrate obtained by isoelectric precipitation. •Two methods were compared to produce mealworm protein isolates.•Higher protein content was produced by precipitation vs ultrafiltration.•Production method impacted protein denaturation and surface hydrophobicity.•Protein solubility was higher for ultrafiltration vs isoelectric precipitation.•Longer emulsion stability was obtained for ultrafiltration vs precipitation.