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

Abstract

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.

Physical and Oxidative Stability of Low-Fat Fish Oil-in-Water Emulsions Stabilized with Black Soldier Fly (Hermetia illucens) Larvae Protein Concentrate

“…The peaks at 1647 cm −1 (amide I) and 1538 cm −1 (amide II) are indicative of α-helices conformation, and the presence of shoulder bands at 1626 cm −1 and 1517 cm −1 also indicates some degree of β-sheet secondary structure [ 34 ]. A more detailed analysis can be seen in Figure 2 B, where the Savitsky–Golay method and the second derivative were applied, similarly to a previous study on the protein concentrate of the black soldier fly [ 35 ]. The spectrum shows a qualitative analysis of the amide I region, correlated to C=O stretching.…”

“…A previous work reported the interfacial properties of black soldier fly protein concentrate (BSFPC) using a sunflower oil–water system to measure the decrease in IFT. The study reported that BSFCP instantaneously decreased IFT to 8.4 mN/m and reached 3.4 mN/m after 90 min of experiment [ 35 ]. The author used a 10 times higher protein concentration, 0.1% ( w / w ), compared to the concentration used in this study, 0.01% ( w / w ).…”

“…In addition, it has been reported that sunflower oil-in-water emulsion, stabilized by BSFPC, had a similar result to emulsion stabilized with WPI. Yet, BSFPC successfully reduced the mean droplet diameters of emulsions prepared with 20% to 40% of lemon oil compared to the same emulsions prepared with WPI [35]. The ability of a protein to stabilize emulsions could be an important characteristic required in many food formulations.…”

Polyphenol Loaded W1/O/W2 Emulsions Stabilized with Lesser Mealworm (Alphitobius diaperinus) Protein Concentrate Produced by Membrane Emulsification: Stability under Simulated Storage, Process, and Digestion Conditions

“…The nickel sieve had pores of 284.7 × 12.8 μm (length × width) with a thickness of 120 μm. Glass microbeads of 38 μm (0.44 g) were placed in the module on top of the nickel sieve, which resulted in 2 mm layer with an interstitial void diameter of ~22 μm, as calculated using the literature [ 43 ]. Coarse emulsions were placed in the vessel and immediately passed through the DMTS system pressurized to 500 kPa with N 2 ; this process is called one emulsification cycle.…”

“…In addition, enzymatic hydrolysis of the protein extracts could efficiently enhance their functionalities and obtain bioactive peptides with antioxidative, antihypertensive, antidiabetic, and antimicrobial properties [ 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. Regarding studies in emulsions stabilized with insect proteins, Wang et al [ 43 ] reported a superior performance of black soldier fly ( Hermetia illucens ) protein concentrate on emulsifying a high fraction (40 wt%) of lemon oil compared to whey protein isolate (WPI), and Gould and Wolf [ 44 ] found that sunflower oil emulsions stabilized with mealworm protein displayed smaller droplet size and a lower protein concentration was required compared to WPI; in addition, the produced emulsion also showed great stability under wide environmental stresses (temperature at −20 °C and 60–90 °C, pH 3–8 and ionic strength 80–330 mM). These results show the potential use of insect proteins to stabilize emulsions and are a good starting point to broaden their use to more complex systems, such as W 1 /O/W 2 emulsions.…”