The structural modifications and techno-functional properties of yellow mealworm protein concentrate is influenced by the presence of residual lipids

In this study, we compared the impact of partial and total defatting by using hexane and chloroform-methanol respectively, on the lipid and protein profiles, protein structure, and techno-functional properties of a yellow mealworm protein concentrate to address the influence of residuals lipids. The results showed significant changes in the particle size distribution (bimodal versus monomodal), surface hydrophobicity (49.35 vs 21.74 a.u.), and secondary structure of the proteins following defatting. Phospholipids accounted for 60% of the residual lipids content. Although residual lipids after Soxhlet extraction did not notably influence protein solubility except at pH 6 (49.74% after total defatting compared to 59.28% after partial defatting), they negatively impacted foaming properties (foam stability of 100% vs 65% after 30 min) and induced higher emulsifying properties (3.23 vs 2.57 for emulsion stability index) of the mealworm protein extract. Consequently, the residual lipids content after Soxhlet extraction of mealworm protein ingredients appears as an important parameter to consider in determining techno-functional properties.