Recent Insight on Edible Insect Protein: Extraction, Functional Properties, Allergenicity, Bioactivity, and Applications

Methods of Protein Extraction from House Crickets (Acheta domesticus) for Food Purposes

Global population is projected to reach 9.1 billion by 2050, emphasizing the need for increased food production. Edible insects, such as house crickets (Acheta domesticus), emerged as promising due to higher nutritional value and efficient feed conversion rates compared to conventional protein sources. Incorporating insect powders into new food products can improve consumer acceptance but often leads to poor technological food processing functionality and/or undesirable organoleptic characteristics. Protein isolates have proven to be effective in enhancing this functionality and consumer acceptance, but existent protein extraction methods still lack improvements concerning the optimization of protein extraction rates. This study aimed to address this gap by developing and comparing the yield of three different protein extraction methods using sodium hydroxide, ascorbic acid or alcalase from house crickets (Acheta domesticus) for food applications. Protein extraction was performed on cricket powder with a mean protein content of 46.35 g/100 g, and the results were evaluated. The enzymatic method shows the highest protein extraction rate at 69.91% with a mean protein content of 60.19 g/100 g, while extraction with NaOH or ascorbic acid resulted in rates of 60.44 and 46.34%, respectively. Further studies on technological food processing functionality and sensorial evaluation of products developed with this protein extract are recommended.

Review: Insects as a novel feed ingredient: processing technologies, quality and safety considerations

The current food system is placing significant strain on limited available resources. Novel protein sources have been suggested as a potential solution for ensuring further growth without compromising the natural balance of the planet. In this direction, edible insects appear to be crucial players. Consumers may not always prefer the direct use of insects as human food, indicating that the indirect use of insects as animal feed might be more suitable. Insects are characterised by high nutritional value and similar digestibility compared to more traditional feed such as soybean meal and fishmeal. However, effective introduction of edible insects in animal diets requires one or more processing operations. Processing is paramount for ensuring high microbiological safety while improving the quality, digestibility and palatability of the insect. Additionally, feed processing could allow a combination of insect-based ingredients with other traditional feed ingredients, obtaining a uniform and stable mixture, which can easily and conveniently be provided to the farmed animals. In this review, an overview of the most common processing methods (blanching, grinding, drying, mixing, extrusion) applied to edible insects with the aim of delivering high-quality insect-based feed is presented. Each processing step is carefully evaluated, the pros and cons of each operation are considered and important recommendations are provided. Barriers and opportunities for advancing the use of insects within the feed sector are finally illustrated. A strong emphasis is placed on the need of evaluating the effect of any processing step on the quality and safety of insect-derived products, particularly considering the possibility of replacing traditional feed ingredients with insect-derived materials.

Selenium Treatment Alleviates the Inhibition Caused by Nep-L Gene Knockdown in Silkworm (Bombyx mori)

Recent studies have emphasized the beneficial effects of 50 μM selenium (Se) on the growth and development of the silkworm, Bombyx mori; however, less is known about its underlying mechanism. To unravel the effect of 50 μM Se on the silkworms with neutral endopeptidase 24.11-like gene (NEP-L) knockdown, we injected small interfering RNA (siRNA) into the body cavity of silkworms. Phenotypic characteristics, mRNA expression of the Nep-L gene, and enriched Se content were evaluated in silkworms from each treatment group. After injecting Nep-L siRNA, the body weight, cocoon quality (cocoon weight, cocoon shell weight, and cocoon shell ratio), and egg production of silkworms were significantly reduced, without any significant effect on egg laying number. However, Se treatment could significantly alleviate the inhibition of body weight, and cocoon quality, without significant effects on egg laying number and production. In addition, the gene knockdown increased Se content in the B. mori. On the molecular level, the targeted Nep-L gene was inhibited significantly by siRNA interference, essentially with the strongest effect at 24 h after RNAi, followed by steady recovery. Among the three fragments, the siRNA of Nep-L-3 was the most effective in interfering with target gene expression. Nep-L gene showed the highest expression in Malpighian tubules (MTs). Both at the phenotypic and genotypic levels, our results show that Nep-L knockdown can exert a significant inhibitory effect on silkworms, and 50 μM Se can reverse the negative effect, which provides a practical prospect for strengthening the silkworm food industry.

Protein hydrolysates derived from superworm (Zophobas morio): Composition, bioactivity, and techno-functional properties

This study aimed to produce protein hydrolysates from superworm (Zophobas morio) flour using the enzymes alcalase (HA), protamex (HP), or flavourzyme (HF), and to characterize their nutritional composition, techno-functional properties, bioactive capacity, and bioaccessibility index. The enzymatic process increased the total amino acid and crude protein contents of the hydrolysates by approximately 36 % and 46 %, respectively, generating better foaming capacity, oil retention, and emulsification capacity, when compared to raw flour. Although 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical capture was similar between the hydrolysates, HA (1479,66 μM FeSO4/g) and HP (1514,66 μM FeSO4/g) showed greater antimicrobial and iron reducing power (FRAP) activity, while HF has a higher scavenging efficiency for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (27.53 %). The best antimicrobial activity was observed for HA against Vibrio corallilyticus (400 mg/mL), and HP showed a better antioxidant response scavenging for DPPH radical. The antioxidant capacity against ABTS radical after in vitro simulation of gastrointestinal digestion (GID) was as follows: HA (79.07 ± 1.53 %), HP (74.65 ± 5.85 %), and HF (57.95 ± 8.31 %). Therefore, insect flour is a promising ingredient for the production of protein hydrolysates and their application in animal and human feeds.

Impact of High Hydrostatic Pressure on the Physicochemical Characteristics, Functional Properties, Structure, and Bioactivities of Tenebrio molitor Protein

This study aimed to explore the influence of high hydrostatic pressure (HHP) treatment on the structure, functional characteristics, and bioactivities of Tenebrio molitor protein. The results showed that HHP induced dissociation of T. molitor protein, exposing hydrophobic groups and reducing particle size, which in turn reduced turbidity. Additionally, 600 MPa treatment significantly reduced the foaming stability and emulsifying activity of T. molitor protein. Treatments at 200 MPa and 400 MPa significantly reduced emulsion stability, whereas 400 MPa treatment significantly increased oil retention. HHP treatment also altered the secondary and tertiary structures of T. molitor protein, as demonstrated by circular dichroism and fluorescence spectra. Furthermore, HHP treatment significantly affected the antibacterial and antioxidant activities of T. molitor protein. This study provides a theoretical framework for using HHP to modify T. molitor protein.

An Investigation of the Status of Commercial Meat Analogs and Their Ingredients: Worldwide and South Korea

Meat analogs are a burgeoning industry, with plant-based meat analogs, insect-based meat analogs, algae-based meat analogs, mycoprotein-based meat analogs, and cell-based meat analogs. However, despite the industry's growth potential, market expansion faces hurdles due to taste and quality disparities compared to traditional meats. The composition and characteristics of meat analogs currently available in the market are analyzed in this study to inform the development of future products in this sector. The results show that plant-based meat analogs are mainly based on soy protein together with wheat gluten and methylcellulose or spices. Insect-based meat analogs tend to contain processed larvae as the protein source. Seaweed or spirulina is often the main ingredient in algae-based meat analogs. Mycoprotein-based meat analogs all use mycoproteins. Cell-based beef, pork, chicken, and seafood products are already under various stages of development around the world, although many are still at the prototype level.

Exploring Sustainable Future Protein Sources

With the exponential growth of the world population and the decline in agricultural production due to global warming, it is predicted that there will be an inevitable shortage of food and meat resources in the future. The global meat consumption, which reached 328 million tons in 2021, is expected to increase by about 70% by 2050, and the existing livestock industry, which utilizes limited resources, is having difficulty meeting the demand. Accordingly, cultured meat produced by culturing cells in the laboratory, edible insects consumed after cooking or processing, and plant-based meat processed by extracting proteins from plants have been proposed as sustainable food alternatives. These future protein sources are gaining popularity among consumers who prefer a healthy diet due to their nutritional benefits, and they are receiving attention for their potential to reduce environmental impact. This review describes the types and characteristics of protein sources such as cultured meat, antiserum media, edible insects, soy protein, wheat protein, and other mushroom mycelia, processing processes and technologies, market status, institutional challenges and prospects, and mushroom cultured meat.

Physicochemical and techno-functional characterization of soluble proteins extracted by ultrasound from the cricket Acheta domesticus

The growing interest in using insects for human consumption is due to their numerous benefits. Insects offer efficient protein generation, rapid growth rates, and high nutritional value. The objective of this work was to evaluate the physicochemical and techno-functional properties of the different soluble protein fractions of the cricket Acheta domesticus using various methods: grinding (CF), defatting (DCF), alkalinization (SPA), and ultrasound-assisted extraction (SPS). CF, DCF, SPA, and SPS were used as extenders in food models and compared with a control group prepared with meat and a commercial soy protein (SPI). Defatting increased the protein content (52 %) in CF, improving digestibility, while the SPS extraction method improved solid recovery (40.46 %), protein recovery (41.94 %), total protein content (53.85 %), and digestibility (53.7 %) compared to SPA. Proteins exhibited pH-dependent solubility, with higher solubility at pH 12-13 and an isoelectric point of 4.5. In techno-functional properties, SPS had the highest water/oil retention capacity (2.8 g/g, 3.49 g/g), foam formation (386.66 %), and emulsifying stability (32.96 m2/g). CF showed no foam formation, although defatting (DCF) improved foam formation (8.33 %) and emulsifying stability (6.23 m2/g). Heat coagulation was higher for CF and DCF (30.58 % and 30.33 % respectively). All meat models with SPA and SPS showed high elasticity and cohesiveness but low hardness, gumminess, and chewiness. The model prepared with 15 % SPS reduced cooking losses (0.91 %) and total expressible fluid separation (1 %), improved water retention capacity (83.02 %), and increased total soluble protein content (5.32 mg/mL). The ultrasound-assisted extraction method proved to be an efficient way to obtain soluble proteins from Acheta domesticus with techno-functional properties suitable for use as a food additive or meat extender.

Current trends and possibilities of typical microbial protein production approaches: a review

Global population growth and demographic restructuring are driving the food and agriculture sectors to provide greater quantities and varieties of food, of which protein resources are particularly important. Traditional animal-source proteins are becoming increasingly difficult to meet the demand of the current consumer market, and the search for alternative protein sources is urgent. Microbial proteins are biomass obtained from nonpathogenic single-celled organisms, such as bacteria, fungi, and microalgae. They contain large amounts of proteins and essential amino acids as well as a variety of other nutritive substances, which are considered to be promising sustainable alternatives to traditional proteins. In this review, typical approaches to microbial protein synthesis processes were highlighted and the characteristics and applications of different types of microbial proteins were described. Bacteria, fungi, and microalgae can be individually or co-cultured to obtain protein-rich biomass using starch-based raw materials, organic wastes, and one-carbon compounds as fermentation substrates. Microbial proteins have been gradually used in practical applications as foods, nutritional supplements, flavor modifiers, and animal feeds. However, further development and application of microbial proteins require more advanced biotechnological support, screening of good strains, and safety considerations. This review contributes to accelerating the practical application of microbial proteins as a promising alternative protein resource and provides a sustainable solution to the food crisis facing the world.

Impact of salting-in/out assisted extraction on rheological, biological, and digestive, and proteomic properties of Tenebrio molitor larvae protein isolates

In this study, NaCl (salting-in) and (NH4)2SO4 (salting-out) treatments were employed in alkaline extraction and acid precipitation procedures, respectively, to enhance the extraction of Tenebrio molitor larvae protein isolates (TPIs). The in vitro digestibility, rheological properties, biological activities, and proteomic analysis of TPIs were investigated. The results showed that salting-in treatment did not result in significant differences (P > 0.05) in antioxidant activities (except for ABTS radical scavenging), but increased tumor necrosis factor β (TNF-β) and the degree of hydrolysis (DH). Salting-out treatment significantly (P < 0.05) enhanced trichloroacetic acid-soluble peptide yield (Tsp) and ACE inhibitory activities but negatively affected antioxidant and antibacterial activities. The combined salting-in-out treatment produced the highest values of DH (45.80 %), Tsp (72.46 %), and TNF-β (0.86 mg/kg). Proteomic analysis using UPLC-MS/MS identified 141 proteins, including metabolic enzymes and actin, in the TPIs. While the salting treatments did not significantly alter the protein compositions, they primarily affected protein content. Overall, salting-in and salting-out treatments can effectively enhance specific biological properties of T. molitor protein isolates, particularly digestibility and ACE inhibitory activities, while salting-out treatments may reduce antioxidant functions. These findings suggest the potential of salting-assisted extractions for optimizing insect protein functionality in food and nutraceutical applications.

The Biotechnological Potential of Crickets as a Sustainable Protein Source for Fishmeal Replacement in Aquafeed

As aquaculture production grows, so does the demand for quality and cost-effective protein sources. The cost of fishmeal (FM) has increased over the years, leading to increased production costs for formulated aquafeed. Soybean meal (SBM) is commonly used as an FM replacer in aquafeed, but anti-nutritional factors could affect the growth, nutrition, and health of aquatic organisms. Cricket meal (CM) is an alternative source with a nutrient profile comparable to FM due to its high protein content, digestibility, and amino acid profile. CM use in aquafeed influences growth and reproductive performance while modulating the gut microbiota and immune response of fish and shrimp. However, consistent regulation and scaling up are necessary for competitive prices and the marketing of CM. Moreover, the chitin content in CM could be an issue in some fish species; however, different strategies based on food biotechnology can improve the protein quality for its safe use in aquafeed.

Invertebrate composting quality of the invasive alga Rugulopteryx okamurae, prospects for its bio-recycling, management and circular economy

In recent decades, the invasive seaweed Rugulopteryx okamurae has had a huge environmental impact on marine biodiversity, fisheries, GHG emissions and public health along much of the Iberian Peninsula and islands coastline. Due to the enormous amount of algae biomass that is expelled to the beaches where it slowly rots, some circular economy business initiatives, such as composting, are emerging. In the present study, we compared the quality of compost obtained from earthworms (Dendrobaena veneta), cockroaches (Eublaberus sp.), mealworms (Tenebrio molitor) and black soldier fly larvae (Hermetia illucens). Batches fed with 100% organic kitchen waste (control group) were compared with batches fed with 50% algae and 50% kitchen waste (treatment group). Our results show that the most sensitive species (D. veneta and T. molitor) to R. okamurae toxins compost adequately. The C/N ratio, electrical conductivity (EC), pH, total organic matter (TOM), C, K, K2O, Mg, MgO, N, P, P2O5, B, Cu, Ni and Zn of the compost obtained were determined. A high quality compost was obtained in which only the EC values are slightly elevated. Particularly good was the compost obtained with H. illucens and Eublaberus sp. This quality is in agreement with previous research on the mass balance of composting. Therefore, both species offer, in the field of circular economy, encouraging prospects for the development of composting enterprises.

Quality Characteristics of Meat Analogs through the Incorporation of Textured Vegetable Protein and Tenebrio molitor Larvae in the Presence of Transglutaminase

Alternative protein sources with greater nutritional value and a lower environmental footprint have recently attracted interest in the production of meat substitutes. However, it is required that these alternatives mimic the texture and structure of meat. This study investigated varying ratios of textured vegetable proteins (TVP) to Tenebrio molitor larvae (brown mealworm; TM) with the addition of transglutaminase (TG) to determine the quality characteristics of these emulsions. The results demonstrated low protein solubility of the emulsions as TVP content increased. Furthermore, when the proportion of TM was high, the TG-treated emulsion had a low pH. Additionally, when there was a high TM ratio to TVP in the TG treatment, the emulsions demonstrated better thermal stability and water holding capacity. Regarding the rheological properties of the emulsion, both the frequency-dependent storage modulus (G') and loss modulus (G'') increased as the proportion of TVP in the emulsion increased with and without the addition of TG. Differential scanning calorimetry analyses demonstrated two protein denaturation peaks in all treatments, with high peak temperatures for both treatments with a high proportion of TM. The hardness and chewiness of the emulsion were highest in the treatment (T6 and T8) with TG, and the gumminess of the emulsion was greatest when TM only or when equal ratios of TVP and TM were treated with TG, respectively. In conclusion, the addition of TM to TVP with TG improves the overall texture of the protein mixture, making it a suitable meat alternative.

Research Progress and Production Status of Edible Insects as Food in China

Based on the background of the exacerbating food shortage in the world, it is particularly important to diversify food resources in every possible direction. Among the choices available, edible insects have become an important alternative source of animal food with their high nutritional and functional (pharmacological) values, partially replacing normally consumed animal and livestock protein food sources. The utilization of edible insects has been an ancient custom since the dawn of civilization, attributed to their rich nutrition, alternate protein source, medicinal values, and presence of diverse secondary metabolites and alkaloids. This review provides an introduction to three key aspects of edible insects as food: freshness, long-term preservation, and medicinal value. It also provides details on the food source and products of edible insect species, their detailed nutritional composition and medicinal values, and their potential in producing alternative protein sources. Additionally, the review also encompasses rearing and producing technologies, resource utilization, and industrial development in China. Simultaneously, the problems and challenges faced in the artificial rearing and production development of edible insects, the production advantages over traditional livestock, and the farming evaluation and prospects of edible insects, as well as the lack of specific legislation on edible insects in China, are discussed. This review will be helpful in scientific knowledge propagation regarding edible insects for the public, guiding consumers to establish a diverse perception of sustainable agriculture and food sources in the world that has, as yet, been thwarted by food insecurity. Moreover, though edible insects could potentially serve as part of a commercial and industrial agri-enterprise that could generate a huge income, artificial rearing technology and edible insect product manufacturing and processing have not received sufficient attention from the government on a policy level, thereby leaving an open space for extensive research on edible insects as an alternate food source as well as an examination of the industrial prospects of edible insect products.

Unlocking the Potential of Insect-Based Proteins: Sustainable Solutions for Global Food Security and Nutrition

The present review highlights the potential of insect-based proteins to address the growing need for sustainable and secure food systems. The key findings suggest that edible insects offer a viable and environmentally friendly alternative to traditional livestock, requiring significantly less land, water, and feed while emitting lower levels of greenhouse gases. Insect farming can also reduce waste and recycle nutrients, supporting circular economy models. Nutritionally, insects provide high-quality protein, essential amino acids, and beneficial fats, making them valuable to human diets. Despite these benefits, this review emphasizes the need for comprehensive regulatory frameworks to ensure food safety, manage potential allergenicity, and mitigate contamination risks from pathogens and environmental toxins. Additionally, developing innovative processing technologies can enhance the palatability and marketability of insect-based products, promoting consumer acceptance. This review concludes that with appropriate regulatory support and technological advancements, insect-based proteins have the potential to significantly contribute to global food security and sustainability efforts.

Evaluating bio-physicochemical properties of raw powder prepared from whole larvae containing liquid silk of the domestic silkworm

The domestic silkworm, Bombyx mori, has been widely used in silk production for centuries. It is also used as a bioreactor by the textile and pharmaceutical industries to mass produce recombinant bioactive proteins containing silk-based materials. Furthermore, silkworms are well-known as a source of food and have also been orally administered to prevent and treat several human disorders. In this study, we aimed to investigate the inherent bio-physicochemical properties of edible silkworms to accurately evaluate their clinical and nutritional potential. We prepared raw powder from whole larvae of silkworm. The yield rate of the powder derived from dried larvae was almost 100% (98.1-99.1% in replicates). As "percentage yield" translates to "Budomari" in Japanese, this raw powder was named "B100rw." We further prepared B100dn that was denatured through autoclaving. Thereafter, we examined whether B100rw sustained the original bio-physicochemical properties by comparing it with B100dn. There was no significant difference in nutritional content between B100rw and B100dn. B100rw contained proteins derived from silkworm larvae and mulberry leaves, whereas the proteins of B100dn were mostly degraded. On measuring the enzymatic activity of both powders using trehalase as an indicator enzyme, B100rw was found to maintain trehalase activity. B100rw also maintained a random coil conformation, similar to that of liquid silk. This suggested that B100rw sustained the unique bio-physicochemical properties of living larvae. These findings may facilitate the development of novel food products or orally administered vaccines.

Insights into Cold Plasma Treatment on the Cereal and Legume Proteins Modification: Principle, Mechanism, and Application

Cereal and legume proteins, pivotal for human health, significantly influence the quality and stability of processed foods. Despite their importance, the inherent limited functional properties of these natural proteins constrain their utility across various sectors, including the food, packaging, and pharmaceutical industries. Enhancing functional attributes of cereal and legume proteins through scientific and technological interventions is essential to broadening their application. Cold plasma (CP) technology, characterized by its non-toxic, non-thermal nature, presents numerous benefits such as low operational temperatures, lack of external chemical reagents, and cost-effectiveness. It holds the promise of improving proteins' functionality while maximally retaining their nutritional content. This review delves into the pros and cons of different cold plasma generation techniques, elucidates the underlying mechanisms of protein modification via CP, and thoroughly examines research on the application of cold plasma in augmenting the functional properties of proteins. The aim is to furnish theoretical foundations for leveraging CP technology in the modification of cereal and legume proteins, thereby enhancing their practical applicability in diverse industries.

Structural, extraction and safety aspects of novel alternative proteins from different sources

With rapid population growth and continued environmental degradation, it is no longer sustainable to rely on conventional proteins to meet human requirements. This has prompted the search for novel alternative protein sources of greater sustainability. Currently, proteins of non-conventional origin have been developed, with such alternative protein sources including plants, insects, algae, and even bacteria and fungi. Most of these protein sources have a high protein content, along with a balanced amino acid composition, and are regarded as healthy and nutritious sources of protein. While these novel alternative proteins have excellent nutritional, research on their structure are still at a preliminary stage, particularly so for insects, algae, bacteria, and fungi. Therefore, this review provides a comprehensive overview of promising novel alternative proteins developed in recent years with a focus on their nutrition, sustainability, classification, and structure. In addition, methods of extraction and potential safety factors for these proteins are summarized.

Conjugation of lesser mealworm (Alphitobius diaperinus) larvae protein with polyphenols for the development of innovative antioxidant emulsifiers

Lesser mealworm protein concentrate (LMPC) was conjugated with chlorogenic acid (CA) or tannic acid (TA) using an alkaline method. The impact of polyphenol type and concentration on the physicochemical and structural characteristics, antioxidant, interfacial, and emulsifying properties of the LMPC-polyphenol conjugates were investigated. Under the conditions tested, TA demonstrated higher affinity for LMPC compared to CA. The conjugation of LMPC induced conformational changes as showed by intrinsic fluorescence and FT-MIR raw spectra analysis. The surface hydrophobicity of the conjugates was reduced, leading to increased interfacial tension values for LMPC-TA conjugates without impairment of the emulsifying activity. The antioxidant properties were significantly improved by the conjugation. Flaxseed oil-in-water (O/W) emulsions stabilized by the conjugates and LMPC remained physically stable for 12 days at 50 °C with a notable reduction of secondary oxidation products when conjugates were used. LMPC-TA and LMPC-CA exhibited potential to be used as novel antioxidant emulsifiers in O/W emulsions.

Use of a Silkworm (Bombyx mori) Larvae By-Product for the Treatment of Atopic Dermatitis: Inhibition of NF-κB Nuclear Translocation and MAPK Signaling

Atopic dermatitis (AD) is a long-lasting inflammatory skin disease that contributes to the global health burden and impacts 10–20% of the world’s population. In this study, we determined the anti-AD effect of a by-product of silkworm (Bombyx mori) larval powder, strain Yeonnokjam (SLPY), as a sustainable, natural source for the development of therapeutic agents for AD. HaCaT cells were used to assess the in vitro anti-inflammatory activity of SLPY, and a 1-chloro-2,4-dinitrobenzene (DNCB)-induced mouse model was used to study the in vivo anti-AD effects. SLPY treatment downregulated the expression of the inflammatory cytokines TNF-α, IL1β, IL-8, and Cox-2 in stimulated HaCaT cells. Similarly, the topical application of SLPY in DNCB-treated mice downregulated the expression of inflammatory cytokines and proteins while ameliorating the clinical features of AD. Further, SLPY treatment inhibited the nuclear translocation of NF-κb p65, thereby supporting the efficacy of SLPY in the treatment of AD.

Alternative Protein Sources and Novel Foods: Benefits, Food Applications and Safety Issues

The increasing size of the human population and the shortage of highly valuable proteinaceous ingredients has prompted the international community to scout for new, sustainable, and natural protein resources from invertebrates (e.g., insects) and underutilized legume crops, unexploited terrestrial and aquatic weeds, and fungi. Insect proteins are known for their nutritional value, being rich in proteins with a good balance of essential amino acids and being a valuable source of essential fatty acids and trace elements. Unconventional legume crops were found rich in nutritional, phytochemical, and therapeutic properties, showing excellent abilities to survive extreme environmental conditions. This review evaluates the recent state of underutilized legume crops, aquatic weeds, fungi, and insects intended as alternative protein sources, from ingredient production to their incorporation in food products, including their food formulations and the functional characteristics of alternative plant-based proteins and edible insect proteins as novel foods. Emphasis is also placed on safety issues due to the presence of anti-nutritional factors and allergenic proteins in insects and/or underutilized legumes. The functional and biological activities of protein hydrolysates from different protein sources are reviewed, along with bioactive peptides displaying antihypertensive, antioxidant, antidiabetic, and/or antimicrobial activity. Due to the healthy properties of these foods for the high abundance of bioactive peptides and phytochemicals, more consumers are expected to turn to vegetarianism or veganism in the future, and the increasing demand for such products will be a challenge for the future.

Evaluation of Anti-Oxinflammatory and ACE-Inhibitory Properties of Protein Hydrolysates Obtained from Edible Non-Mulberry Silkworm Pupae (Antheraea assama and Philosomia ricinii)

Food-derived bioactive peptides (BAPs) obtained from edible insect-protein hold multiple activities promising the potential to target complex pathological mechanisms responsible for chronic health conditions such as hypertension development. In this study, enzymatic protein hydrolysates from non-mulberry edible silkworm Antheraea assama (Muga) and Philosomia ricini (Eri) pupae, specifically Alcalase (A. assama) and Papain (P. ricini) hydrolysates obtained after 60 and 240 min, exhibited the highest ACE-inhibitory and antioxidant properties. The hydrolysates' fractions (<3, 3-10 and >10 kDa), specifically Alc_M60min_F3 (≤3 kDa) and Pap_E240min_F3 (≤3 kDa), showed the highest antioxidant and ACE-inhibitory activities, respectively. Further RP-HPLC purified sub-fractions F4 and F6 showed the highest ACE inhibition as well as potent anti-oxinflammatory activities in lipopolysaccharide (LPS)-treated endothelial cells. Indeed, F4 and F6 ACE-inhibitory peptide fractions were effective in preventing p65 nuclear translocation after 3 h of LPS stimulation along with the inhibition of p38 MAPK phosphorylation in HUVEC cells. In addition, pretreatment with F4 and F6 ACE-inhibitory peptide fractions significantly prevented the LPS-induced upregulation of COX-2 expression and IL-1β secretion, while the expression of NRF2 (nuclear factor erythroid 2-related factor 2)-regulated enzymes such as HO-1 and NQO1 was induced by both peptide fractions. The derived peptides from edible pupae protein hydrolysates have potentialities to be explored as nutritional approaches against hypertension and related cardiovascular diseases.

Cytoprotective and Antioxidant Effects of Hydrolysates from Black Soldier Fly (Hermetia illucens)

The black soldier fly (BSF), Hermetia illucens, has been recognized as one of the most promising insect species for its ability to valorize organic waste while producing a valuable larval biomass with a great potential as a sustainable source of nutrients, including proteins and bioactive molecules. In the present study, BSF larvae were used to produce and characterize the protein hydrolysates (BPHs) that were then evaluated for their potential biological activity in vitro. The BPHs obtained from the BSF larvae proteins by enzymatic digestion were characterized by Nuclear Magnetic Resonance (NMR) and polyacrylamide gel electrophoresis and assessed for their antioxidant activity (BPHs in the range of 0.1 to 1.5 mg/mL) in L-929 cells. Our findings show that BPHs can exert a dose-dependent cytoprotective role against H₂O₂-iduced oxidative stress in cells. This antioxidant activity relies on the reduction of ROS levels in challenged cells as measured by flow cytometry and fluorescence microscopy, together with the induction and nuclear translocation of Nrf2, as evaluated by qPCR and indirect immunofluorescence analysis, respectively. Overall, our findings on the remarkable biological activity of the BPHs obtained in a large-scale process strongly suggest the application of BPHs as ingredients promoting animal health in feed formulations.