Effects of Hexane on Protein Profile, Solubility and Foaming Properties of Defatted Proteins Extracted from Tenebrio molitor Larvae

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.

Effect of thermal and defatting treatments on the composition, protein profile and structure of house cricket (Acheta domesticus) protein extracts

This study investigated the impact of blanching (100 °C, 40 s), defatting method (maceration, Soxhlet) and solvent polarity (hexane, ethanol) on the profile, structure and solubility of house cricket protein extracts. Blanching and Soxhlet using ethanol impacted the protein profile, with a lower content of myosin heavy chain and a higher abundance of low molecular weight proteins (<25 kDa). Moreover, ethanol induced aggregation of non-blanched cricket proteins, with a 13-72% reduction in protein recovery yield. The protein secondary structure of non-blanched extracts was also affected by ethanol with 18% more β-sheets. Furthermore, blanching resulted in a lower protein surface hydrophobicity by a factor of 3 to 7, with no impact of solvent polarity. Finally, the solubility of protein extracts remained >75%, regardless of the blanching and defatting methods. These findings, combined with the evaluation of techno-functional properties, could be used for the development of cricket-based protein ingredients for food formulations.

How the presence of residual lipids in a yellow mealworm protein concentrate affects its foaming properties?

The use of whole and visible insects is poorly accepted in Western countries, and this remains a significant challenge for product development. However, using insect-based protein-rich ingredients, like protein concentrate, can improve levels of consumer approval. The residual lipid content in insect protein concentrates can influence their techno-functional properties. Our study therefore aimed to evaluate the impact of the residual lipid content on the protein structure and foaming properties of a mealworm protein concentrate. Our results showed that the protein content increased from 78.01 to 84.82 % after using chloroform-methanol for lipid removal. The particle size distribution shifted from a bimodal to a unimodal pattern, and the surface hydrophobicity decreased from 267.02 to 48.91 after completely removing lipids by chloroform-methanol, with no noticeable impact on the protein profile. The foaming capacity improved, resulting in the formation of a firm and fluffy foam with high stability over time. These results highlight the importance of controlling the residual lipid content in mealworm protein concentrates to enhance their techno-functional properties. The next steps will entail comprehensively characterizing the lipid profile and exploring the various mechanisms contributing to the techno-functional properties.

Nutritional composition and techno-functionality of non-defatted and defatted flour of edible insect Arsenura armida

Edible insects are traditional foods worldwide, and in Mexico, is a prehispanic practice. Nowadays, edible insects can be a food source for the increasing population. This research aimed to evaluate the nutritional profile, physical and techno-functional characteristics of non-defatted (NDF) and defatted (DF) flour of the edible insect Arsenura armida to use as a functional ingredient. The lipid content in NDF was 24.18%. Both flours are high in protein, 20.36% in NDF and 46.89% in DF; their soluble proteins from A. armida were classified according to their molecular weight, which ranged from 12 to 94 kDa. The physical properties suggest that both flours have good flow characteristics. Regarding techno-functional properties, DF had the highest water (275.6%) and oil (121%) holding capacity values. The viscosity values indicate that they behave as a non-Newtonian shear-thinning fluid at a high concentration (20%). Emulsion capacity values range between 78.3 and 100% in both flours, with stability between 92.4 and 100%. These flours could be a good source of nutrients, and their techno-functional properties make them a good option for animal protein substitutes.

Effects of hexane on protein profile and techno-functional properties of pea protein isolates

The defatting of legume flours with hexane is usually the first step in producing protein-rich ingredients. However, its impact on protein profiles, zeta potential, surface hydrophobicity and techno-functionality of pea proteins has not been evaluated. Consequently, this work aimed to evaluate the impact of the hexane defatting step on pea protein profiles, surface hydrophobicity and zeta potential, as well as techno-functional properties of non-defatted and defatted pea protein isolates. The results showed that alkaline extraction of hexane-defatted pea flour increased the net surface charge (zeta-potential) and reduced particle size of the pea protein isolate. Moreover, only the foaming properties of pea protein isolate generated from defatted pea flour were improved. Consequently, except for improving foaming properties, the defatting step is not essential for the production of pea protein isolate.

Improvements in Visual Aspects and Chemical, Techno-Functional and Rheological Characteristics of Cricket Powder (Gryllus bimaculatus) by Solvent Treatment for Food Utilization

This study aimed to improve the visual aspects and chemical, techno-functional and rheological characteristics of Gryllus bimaculatus cricket powder through the use of different solvents, with the objective of using it as a protein source in food production. Four treatments (pH 5 aqueous solution, ethanol 20%, ethanol 99.5%, and hexane) were applied to the powder, and analyses were conducted to assess changes in the previously mentioned parameters. The results showed that the treatments led to an increase in protein concentration (from 55.4 to 72.5%) and a decrease in fat concentration (from 33.0 to 6.8%) in ethanol 99.5% treated powder, as well as a reduction in anti-nutritional compounds concentration, such as tannins (from 13.3 to 5.9 g/kg), in pH 5 treated powder, which is important for the nutritional value of the final product. The color of the powders was improved, being lighter after hexane and ethanol 99.5% treatments due to the removal of melanin with the defatting process. Flowability, water, and oil holding capacity were also improved in the defatted powders. All the results suggest that the main composition of the powder directly influences the analyzed parameters. These findings suggest that cricket powder treated with solvents can be used as a protein source in different food applications.

Emerging Protein Sources for Food Production and Human Nutrition

It is estimated that by 2050, the world’s population will be up to 9 billion [...]

Unpacking the Proteome and Metaproteome of the Black Soldier Fly Larvae: Efficacy and Complementarity of Multiple Protein Extraction Protocols

The larvae of the black soldier fly (BSF), Hermetia illucens (Diptera: Stratiomyidae), have demonstrated the ability to efficiently bioconvert organic waste into a sustainable source of food and feed, but fundamental biology remains to be discovered to exploit their full biodegradative potential. Herein, LC-MS/MS was used to assess the efficiency of eight differing extraction protocols to build foundational knowledge regarding the proteome landscape of both the BSF larvae body and gut. Each protocol yielded complementary information to improve BSF proteome coverage. Protocol 8 (liquid nitrogen, defatting, and urea/thiourea/chaps) was better than all other protocols for the protein extraction from larvae gut samples, and the exclusion of defatting steps yielded the highest number of proteins for the larval body samples. Protocol-specific functional annotation using protein level information has shown that the selection of extraction buffer can affect protein detection and their associated functional classes within the measured BSF larval gut proteome. A targeted LC-MRM-MS experiment was performed on the selected enzyme subclasses to assess the influence of protocol composition using peptide abundance measurements. Metaproteome analysis of the BSF larvae gut has uncovered the prevalence of two bacterial phyla: actinobacteria and proteobacteria. We envisage that using complementary extraction protocols and investigating the proteome from the BSF body and gut separately will expand the fundamental knowledge of the BSF proteome and thereby provide translational opportunities for future research to enhance their efficiency for waste degradation and contribution to the circular economy.

Evaluating the Functional Characteristics of Certain Insect Flours (Non-Defatted/Defatted Flour) and Their Protein Preparations

Edible insects as an alternative source of protein are gaining increasing attention, leading to new opportunities for their use in food processing. In this study, the functional properties, such as water and oil holding capacity, foaming, and emulsifying properties, of the most popular insect forms (flour, defatted flour, and protein preparations), such as Gryllus asimillis, Acheta domesticus, and Zophobas morio, were studied. Moreover, proximate analysis, protein extraction yield and efficiency, and sensory analysis, were evaluated. Defatting the flours yielded the highest protein content of all the insect forms tested, in the range of 70.51 to 76.02%, significantly reducing their calorific value by up to 35% for Z. morio. Generally, protein preparations exhibit the best functional properties among studied forms, and the most significant differences are noticeable in foaming capacity—near 30% higher than flours. Furthermore, all samples scored well in the sensory test (overall score 3.76–4.47) except for the Z. morio flour (2.93), which may exclude it from being used in the food industry. The results show that the insect forms studied, due to their good functional properties, can become a valuable component of food recipes, positively impacting the characteristics of the designed food.