Mealworm, TM (Tenebrio molitor), and black soldier fly, BSF (Hermetia illucens) are of special interest for food and feed applications due to their environmental benefits such as low water and land requirements, low greenhouse gas emissions, and high feed-conversion efficiency. This study assesses the use of ultrafiltration (UF) to fractionate protein concentrates from TM and BSF (TMPC, BSFPC) in order to enhance emulsifying and foaming properties. A 30 kDa regenerated cellulose acetate membrane enabled the separation of concentrate and permeate fractions for both insect proteins from two different initial feed concentrations (10 and 7.5 g/L). Permeate flux and protein transmission behave differently depending on the insect type and the initial concentration; while for TMPC permeate flux increases with a decrease in the initial protein concentration, it is not affected for BSFPC. The existing membrane cleaning protocols are suitable for recovering water flux after UF of insect proteins, enabling membrane re-use. Emulsifying activity is maintained for all the TMPC fractions, but it is significantly lower for the permeate fractions of BSFPC. Foaming properties are maintained for all the UF fractions of BSFPC and the ones from 7.5 g/L TMPC. Acidic solubilization leads to a fraction with enhanced emulsifying capacity and one with higher foaming capacity than the original for BSFPC. This study opens the door to membrane technology for insect protein fractionation, which has not been studied so far and has already provided useful solutions for other animal and plant proteins.

The effectiveness of high pressure-assisted extraction (HPAE) in improving insect protein extraction and functionality was studied. Defatted insect powders of Tenebrio molitor and Alphitobius diaperinus were pressure treated at 100–300 MPa for 5 min at 25 °C. Protein content, molecular weight distribution (MWD) of protein fractions, emulsifying activity (EA), and modifications in the secondary structure of the proteins were assessed for the different fractions. In comparison to control, HPAE at 100, 250, and 300 MPa enhanced protein extraction by approximately 18% for both insect species. A 22% increase in protein extraction was observed for A. diaperinus at 200 MPa compared to the control. A clear decrease in EA was noted for both T. molitor and A. diaperinus proteins extracted at 150, 200, 250, and 300 MPa. The MWD analysis indicated that HPEA increased the intensity of protein bands between 10–20 kDa and around 37 kDa for both insect species. This study demonstrates the potential of high pressure to not only enhance protein extraction by up to 22% but also to modify the emulsifying activity of insect proteins.

The main objective of this research was to evaluate the performance of portable FT-MIR (4000 to 630 cm ⁻¹ ) and handheld FT-NIR (7400 to 4000 cm ⁻¹ ) spectrometers, combined with partial least squares regression (PLSR) multivariate analysis. This method was used to predict the percentage of insect lipids added to mixtures of vegetable and seed oils, as well as to profile the fatty acid composition in the lipid fractions of Locusta migratoria and Acheta domesticus mixed with these oils. Insect lipids from L. migratoria and A. domesticus were extracted from their powdered forms using organic solvent extraction and then mixed with five edible oils (olive, sunflower, avocado, almond, and linseed) at concentration ratios ranging from 0 to 100% (n = 140). The fatty acid (FA) profile of the samples was determined using the fatty acid methyl ester (FAME) method. PLSR was used to develop algorithms for predicting insect lipid content in mixtures and FA composition. The PLSR model for predicting the percentage of insect lipids in mixtures with vegetable and seed oils demonstrated good linearity, with high correlation ( R _CV = 0.99), low standard errors of cross-validation (SE _CV ≤ 2.21%) and prediction (SE _P ≤ 2.32%), and high predictive performance as indicated by the ratio of prediction to deviation (RPD ≥ 9.23). The percentage of myristic, palmitic, stearic, oleic, linoleic, and α-linolenic fatty acid as well as the content of saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) were accurately predicted with values of SE _CV ≤ 4.64% and an R _CV ≥ 0.88. However, the FT-MIR spectrometer tested showed superior performance in predicting fatty acids and SFA, MUFA, PUFA reaching values of 0.99 in coefficient of correlation (RP) and 0.66% in standard error in prediction (SE _P ).