Lesser mealworm (A. diaperinus) protein as a replacement for dairy proteins in the production of O/W emulsions: Droplet coalescence studies using microfluidics under controlled conditions.

Dairy proteins are commonly used to stabilize oil-in-water (O/W) emulsions, which can be replaced by other sustainable sources of proteins, such as insects. This study investigated the potential of lesser mealworm protein concentrate (LMPC) as a sustainable alternative to whey protein isolate (WPI) in stabilizing oil-in-water (O/W) emulsions using microfluidics. The frequency of coalescence (Fcoal) was calculated using images of emulsion droplets obtained near the inlet and outlet of the coalescence channel. The stability of O/W emulsions, produced using sunflower oil (SFO) or hexadecane and stabilized with varying concentrations of LMPC and WPI (0.02% to 0.0005% w/v), was compared under controlled conditions. The dispersed phase fraction (5.3%-14.3% v/v), protein adsorption time onto oil droplets (0.0398-0.158 s), and pH (pH = 3 and pH = 7) were also studied. Fcoal was greatest (0.42 s-1) when the protein concentration was lowest (0.0005%), the oil percentage was highest (14.3%), the adsorption period was shortest (0.0398 s), and the pH was 3. Droplet diameters did not vary significantly, with values between 55 and 118 µm, across protein concentrations or adsorption periods, but a rise in oil fraction resulted in a substantial increase in droplet diameters. Increases in protein content, adsorption duration, and oil percentage all resulted in increased stability (reduction of Fcoal). While LMPC and WPI showed similar results in microfluidic experiments and other test conditions, further research is needed to verify LMPC's efficacy as a replacement for WPI in food emulsification. Nonetheless, the findings suggest that LMPC has potential as a substitute for WPI in this application.

Black Soldier Fly (Hermetia illucens) Protein Concentrates as a Sustainable Source to Stabilize O/W Emulsions Produced by a Low-Energy High-Throughput Emulsification Technology.

There is a pressing need to extend the knowledge on the properties of insect protein fractions to boost their use in the food industry. In this study several techno-functional properties of a black soldier fly (Hermetia illucens) protein concentrate (BSFPC) obtained by solubilization and precipitation at pH 4.0-4.3 were investigated and compared with whey protein isolate (WPI), a conventional dairy protein used to stabilize food emulsions. The extraction method applied resulted in a BSFPC with a protein content of 62.44% (Kp factor 5.36) that exhibited comparable or higher values of emulsifying activity and foamability than WPI for the same concentrations, hence, showing the potential for emulsion and foam stabilization. As for the emulsifying properties, the BSFPC (1% and 2%) showed the capacity to stabilize sunflower and lemon oil-in-water emulsions (20%, 30%, and 40% oil fraction) produced by dynamic membranes of tunable pore size (DMTS). It was proved that BSFPC stabilizes sunflower oil-in-water emulsions similarly to WPI, but with a slightly wider droplet size distribution. As for time stability of the sunflower oil emulsions at 25 °C, it was seen that droplet size distribution was maintained for 1% WPI and 2% BSFPC, while for 1% BSFPC there was a slight increase. For lemon oil emulsions, BSFPC showed better emulsifying performance than WPI, which required to be prepared with a pH 7 buffer for lemon oil fractions of 40%, to balance the decrease in the pH caused by the lemon oil water soluble components. The stability of the emulsions was improved when maintained under refrigeration (4 °C) for both BSFPC and WPI. The results of this work point out the feasibility of using BSFPC to stabilize O/W emulsions using a low energy system.