Extraction technique influences the physico-chemical characteristics and functional properties of edible crickets (Acheta domesticus) protein concentrate

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.

Techno-functional properties and structural characteristics of cricket protein concentrates affected by pre-treatments and ultrafiltration/diafiltration processes

This study aimed to evaluate different pre-treatments on cricket flour (CF), solvent-defatting (CFH), and supercritical-defatting (CFS) to obtain cricket protein concentrate (CPC) by ultrafiltration (UF)-diafiltration (DF) and evaluate the UF-DF performance, techno-functional properties, and digestibility. Results showed that defatting efficiency was 63 % and 85 % for solvent-defatting and supercritical fluid defatting, respectively. The supercritical fluid extraction process decreased the protein solubility and affected the UF performance, decreasing protein retention by 33 %. However, the soluble protein of the generated concentrates was higher than 90 %. Protein concentrates showed a better foaming capacity at pH 5.0 and 7.0, while the oil-holding capacity (1.95-2.20 g/g) decreased in defatted concentrates but was higher than water-holding (0.30-0.60 g/g). Emulsion activity (45-50 %) was not affected by pre-treatments (p > 0.05). Protein digestibility ranged from 71 to 75 % (p < 0.05). Supercritical fluid defatting and ultrafiltration-diafiltration processes were suitable for obtaining cricket protein concentrates.

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.

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.

Comparison of Cricket Protein Powder and Whey Protein Digestibility

With the global population projected to reach nine billion by 2050, the search for alternative protein sources has become critical. This study evaluated the digestibility of cricket protein powder compared with that of whey protein powder. Cricket protein powder had a slightly lower protein content but higher fat content than whey protein powder. Although both contained all essential amino acids, their quantities varied. The most abundant essential amino acid was leucine in both samples. The essential amino acid index (EAAI) for cricket protein powder reached 79% when utilising crude protein for calculation. When using the amino acid sum calculation method, it increased by nearly 13%. The EAAI for whey protein was then 94% when calculated based on crude protein, with a slight increase observed when using the amino acid sum calculation method. Cricket protein exhibited a gradual increase in digestibility during intestinal digestion, reaching nearly 80%, whereas whey protein digestibility surpassed 97%. Despite the lower digestibility of cricket protein compared with whey protein, it remains sufficiently high for consideration as a valuable protein source. This study highlights the potential of cricket proteins and underscores the importance of assessing their protein content and digestibility in evaluating their nutritional value.

Protein, lipid, and chitin fractions from insects: Method of extraction, functional properties, and potential applications

Edible insects are accepted as food and feed ingredients in many parts of the world. Insects account for more than 80% of animal kingdom providing rich biodiversity of protein and lipid profiles compared to conventional livestock. Insect biomasses contain an average of 35-62% protein, 3-57% lipid, and 3-12% chitin, and their nutritional values are widely recognized due to their presence, including minerals, and vitamins. While whole insects are consumed as eggs, larvae, pupae, or adults, there has been a recent uptick in interest to use fractions, e.g., protein, lipid, and chitin, as food and feed ingredients. To utilize these fractions in various food and feed preparations, a deeper understanding of the physicochemical as well as functional properties of the ingredients is required, which are generally impacted by extraction and preparation processes. Thus, the methods of extraction/purification are important to preserve the quality and functional properties of these ingredients. This paper discusses the extraction methods for insect protein, lipid, and chitin, their functional properties, and potential applications in food and feed applications.

Physico-chemical, functional, and structural properties of un-defatted, cold and hot defatted yellow lupin protein isolates

This study investigates the structure, physico-chemical and functional properties of yellow lupin isolate protein (YLPI) obtained by different processes (conventional wet and purely aqueous fractionation) from un-defatted (YLPIU), and hot (YLPIHD) and cold (YLPICD) defatted flour. The defatting process modified the physical, structural and functional characteristics of lupin protein isolates. Indeed, a decrease of α-helix, free sulfhydryl groups amount and an increase of disulfide bond levels were observed for defatted samples, improving their emulsifying stability. The defatting process exposes the hydrophobic groups present within the YLPI, which increases total sulfhydryl content and protein surface hydrophobicity. Hot and cold defatting induced a decrease in turbidity, water-holding capacity, oil adsorption capacity, tapped and poured bulk densities. In addition, the defatting process changed the particle size of protein isolates that induced changes in their viscosity. Tryptophan spectra and protein surface hydrophobicity indicated that YLPICD and YLPIHD underwent structural conformational change during the defatting process.

From feed to functionality: Unravelling the nutritional composition and techno-functional properties of insect-based ingredients

In recent years, there has been a growing interest in using insects as a sustainable resource for biorefinery processes. This emerging field aims to convert insect biomass into valuable products while minimizing waste. The integration of emerging green technologies and the efficient extraction of high-value compounds from insects offer promising avenues for addressing the growing demand for sustainable food production and resource utilization. The review examines the impact of dietary modifications on the nutritional profile of insects. It highlights the potential for manipulating insect feed to optimize protein quality, amino acid profile, lipid content and fatty acid composition. Additionally, innovative green processing technologies such as ultrasound, high pressure processing, pulsed electric fields, cold plasma and enzymatic hydrolysis are discussed for their ability to enhance the extraction and techno-functional properties of insect-based ingredients. The review finds that dietary modifications can impact the nutritional composition of insects, allowing the customization of their nutrient content. By optimizing the insect feed, it is possible to increase the quantity and improve the quality of essential nutrients like proteins or lipids in the derived ingredients. Moreover, alternative processing technologies can improve the techno-functional properties (e.g., solubility, water and oil holding capacities, among others) of insect-based ingredients by modifying proteins' conformation. By harnessing these strategies, researchers and industry professionals can unlock the full potential of insects as a sustainable and nutritional food source, paving the way for innovative insect-based food products.

Evaluation of In Vitro Protein Hydrolysis in Seven Insects Approved by the EU for Use as a Protein Alternative in Aquaculture

Rapid population growth is leading to an increase in the demand for high-quality protein such as fish, which has led to a large increase in aquaculture. However, fish feed is dependent on fishmeal. It is necessary to explore more sustainable protein alternatives that can meet the needs of fish. Insects, due to their high protein content and good amino acid profiles, could be a successful alternative to fishmeal and soybean meal traditionally used in sectors such as aquaculture. In this work, seven species of insects (Hermetia illucens, Tenebrio molitor, Acheta domestica, Alphitobius diaperinus, Gryllodes sigillatus, Gryllus assimilis, and Musca domestica) approved by the European Union (UE) for use as feed for farmed animals (aquaculture, poultry, and pigs) were studied. Their proximate composition, hydrolysis of organic matter (OMd), hydrolysis of crude protein (CPd), degree of hydrolysis (DH/NH2 and DH/100 g DM), and total hydrolysis (TH) were analyzed. The results showed that Tenebrio molitor had digestibility similar to that of fishmeal, while Acheta domestica and Hermetia illucens provided similar digestibility to that of soybean meal. The acid detergent fiber (ADF) data were negatively correlated with all protein digestibility variables. The differences in the degree of hydrolysis (DH) results and the similarity in total hydrolysis (TH) results could indicate the slowing effects of ADF on protein digestibility. Further in vivo studies are needed.

Effects of the Incorporation of Male Honey Bees on Dough Properties and on Wheat Flour Bread's Quality Characteristics

Two different levels (5 and 10%) of male honey bees (drones) in powder form were incorporated into wheat flour, and their impact on dough properties and on bread-quality characteristics were investigated. The incorporation of the drone powder to the wheat flour caused a decrease in the extensibility and energy of the dough in the extensograph and an increase in the dough's maximum resistance with increasing levels of the added drone powder. The elongational viscosity values of the dough fortified with drone powder were significantly higher than those of the control wheat flour dough. The breads supplemented with 10% drone powder exhibited lower lightness (L*) values compared to the control bread. The addition of drone powder led to an increase in the total dietary fiber content and insoluble dietary fiber content in the fortified bread. Significant differences in the specific volume values were observed between the control bread and the corresponding ones with 10% drone powder. Upon storage, the moisture content of the crumb of the control bread and of the fortified breads were both significantly decreased, while the addition of the drone powder to the wheat flour bread increased the crumb hardness and gumminess but decreased the cohesiveness of the breads.

Cricket Protein Isolate Extraction: Effect of Ammonium Sulfate on Physicochemical and Functional Properties of Proteins

Crickets are known to be a promising alternative protein source. However, a negative consumer bias and an off-flavor have become obstacles to the use of these insects in the food industry. In this study, we extracted the protein from commercial cricket powder by employing alkaline extraction-acid precipitation and including ammonium sulfate. The physicochemical and functional properties of the proteins were determined. It was found that, upon including 60% ammonium sulfate, the cricket protein isolate (CPI) had the highest protein content (~94%, w/w). The circular dichroism results indicated that a higher amount of ammonium sulfate drastically changed the secondary structure of the CPI by decreasing its α-helix content and enhancing its surface hydrophobicity. The lowest solubility of CPI was observed at pH 5. The CPI also showed better foaming properties and oil-holding capacity (OHC) compared with the cricket powder. In conclusion, adding ammonium sulfate affected the physicochemical and functional properties of the CPI, allowing it to be used as an alternative protein in protein-enriched foods and beverages.

Identification of common cricket (Acheta domesticus) proteins, extracted by acid and alkaline methods

Edible insects currently represent an interesting alternative protein source to the animal ones. The objective of the present wok is to characterize proteins isolated from common cricket (Acheta domesticus). Powder samples of this insect-based flour were obtained using two extraction methods, i.e. acid and alkaline. Subsequently, the proteins isolated have been characterized. The fractionation of proteins in the flour of Acheta domesticus by acid or alkaline-based methods, gave rise to isolates with up to 71.6% in protein content. Extraction in an alkaline medium of insoluble proteins (pellet) resulted in the best performance on protein recovery. These isolates present a wide variety of peptides and proteins, having identified the following ones in the pellet fraction obtained with the acid method: myosin heavy-chain isoforms C, E and Miosin heavy chain (Mhc); tropomyosin; troponin; α and β actin, and some enzymes such as the β subunit ATP synthetase. The characterization results provide information which will enable us to predict the possible physicochemical (gel formation, solubility, water retention capacity, etc.) changes that could take place in the cricket protein during processing in the food and feed industry.

Current state of insect proteins: extraction technologies, bioactive peptides and allergenicity of edible insect proteins

This review aims to provide an updated overview of edible insect proteins and the bioactivity of insect-derived peptides. The essential amino acid content of edible insects is compared with well-known protein sources to demonstrate that edible insects have the potential to cover the protein quality requirements for different groups of the population. Then the current methodologies for insect protein extraction are summarized including a comparison of the protein extraction yield and the final protein content of the resulting products for each method. Furthermore, in order to improve our understanding of insect proteins, their functional properties (such as solubility, foaming capacity, emulsifying, gelation, water holding capacity and oil holding capacity) are discussed. Bioactive peptides can be released according to various enzymatic hydrolysis protocols. In this context, the bioactive properties of insect peptides (antihypertensive, antidiabetic, antioxidant and anti-inflammatory properties) have been discussed. However, the allergens present in insect proteins are still a major concern and an unsolved issue for insect-based product consumption; thus, an analysis of cross reactivity and the different methods available to reduce allergenicity are proposed. Diverse studies of insect protein hydrolysates/peptides have been ultimately promoting the utilization of insect proteins for future perspectives and the emerging processing technologies to enhance the wider utilization of insect proteins for different purposes.

Edible insect as an alternative protein source: a review on the chemistry and functionalities of proteins under different processing methods

The consumption of edible insects can be anadvantageous alternative to the conventional food supply chain, which involves global water waste, land deficit, undernutrition, and starvation. Besides the nutritional aspects, insect proteins have demonstrated a wide range of functional properties such as foamability, emulsifying and gelling abilities. The protein content and amino acid profile of some insects have revealed a good nutritional value and interesting functional properties. However, it is crucial to comprehend how the protein quality is affected by insect feeding, drying, and defatting. There is a knowledge gap about the impact of industrial treatment, such as pH, ionic strength, and heat treatment, on insect proteins' functional properties. In this review, we have aimed to highlight the potential application of insect proteins as a nutritional source and their promising technological applications. The study reported the principal insect protein characterization methodologies that have been investigated in the literature aiming to correlate the physicochemical parameters to possible protein functionalities. The research on the functional properties of insect proteins is at the exploratory level. Further detailed studies are needed to clarify the structure-function relation of insect proteins and how these functionalities and insect processing can increase consumer acceptance.

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.

In Vitro Crude Protein Digestibility of Insects: A Review

The high protein content of insects has been widely studied. They can be a good food alternative, and therefore it is important to study the effect of digestion on their protein. This review examines the different in vitro protein digestibility methodologies used in the study of different edible insects in articles published up to 2021. The most important variables to be taken into account in in vitro hydrolysis are the following: phases (oral, gastric and intestinal), enzymes, incubation time and temperature, method of quantification of protein hydrolysis and sample preprocessing. Insects have high digestibility data, which can increase or decrease depending on the processing of the insect prior to digestion, so it is important to investigate which processing methods improve digestibility. The most commonly used methods are gut extraction, different methods of slaughtering (freezing or blanching), obtaining protein isolates, defatting, thermal processing (drying or cooking) and extrusion. Some limitations have been encountered in discussing the results due to the diversity of methodologies used for digestion and digestibility calculation. In addition, articles evaluating the effect of insect processing are very limited. It is concluded that there is a need for the standardisation of in vitro hydrolysis protocols and their quantification to facilitate comparisons in future research.

Whole Wheat Bread Enriched with Cricket Powder as an Alternative Protein

The current market trends in modern sedentary lifestyles drive the development of new functional products able to fulfill consumers’ demand for a healthy diet. Whole wheat bread contains more protein and fiber than white bread; however, it could be improved in terms of protein content and quality. Cricket powder, which contains high protein (55.11, wt%), could be used as an alternative source to tackle those deficiencies in such bread. Hence, the study aimed to apply cricket powder in the whole wheat bread formula to enrich protein content, indispensable amino acids and determine their physico-chemical properties, consumers’ acceptance, and shelf-life storage. The results showed that all enriched bread presented high protein (18.97−25.94, wt%), fat (10.91−15.07, wt%), and ash (2.09−2.33, wt%) with the increment of the cricket powder than those of the control bread. Enriched breads’ crust colors were not significantly different (p > 0.05), while crumb colors were darker (L* = 55.64−64.48) compared to the control (L* = 69.98). Enriched bread had a hard texture and required a lot of chewing force compared to the control. Furthermore, all samples yielded a shelf-life of 5 days when monitoring the mold growth. From the results, the bread enriched with 20% cricket powder yielded the best consumers’ acceptance score of 77%. It was predominantly high in indispensable amino acids such as leucine, phenylalanine, lysine, and arginine. Therefore, cricket powder could be a novel alternative protein source and successfully utilized in whole wheat bread to enhance its protein content and indispensable amino acids with consumers’ acceptance responding to the current market trend.

Protein Sources Alternative to Meat: State of the Art and Involvement of Fermentation

Meat represents an important protein source, even in developing countries, but its production is scarcely sustainable, and its excessive consumption poses health issues. An increasing number of Western consumers would replace, at least partially, meat with alternative protein sources. This review aims at: (i) depicting nutritional, functional, sensory traits, and critical issues of single-cell proteins (SCP), filamentous fungi, microalgae, vegetables (alone or mixed with milk), and insects and (ii) displaying how fermentation could improve their quality, to facilitate their use as food items/ingredients/supplements. Production of SCP (yeasts, filamentous fungi, microalgae) does not need arable land and potable water and can run continuously, also using wastes and byproducts. Some filamentous fungi are also consumed as edible mushrooms, and others are involved in the fermentation of traditional vegetable-based foods. Cereals, pseudocereals, and legumes may be combined to offer an almost complete amino acid profile. Fermentation of such vegetables, even in combination with milk-based products (e.g., tarhana), could increase nutrient concentrations, including essential amino acids, and improve sensory traits. Different insects could be used, as such or, to increase their acceptability, as ingredient of foods (e.g., pasta). However, insects as a protein source face with safety concerns, cultural constraints, and a lack of international regulatory framework.

Technological Performance of Cricket Powder (Acheta domesticus L.) in Wheat-Based Formulations

The recent socio-economic situation requires producers to change the composition of basic foods. The aim of this study was to assess the technological properties of wheat flour enriched with cricket powder (CP) (at 5%, 10%, and 20% levels) for the development of bread and pasta. The hydration (i.e., water absorption capacity, oil absorption capacity, water absorption index, water solubility index, and swelling power), foaming (i.e., foaming capacity and stability),emulsifying (emulsifying activity and emulsion stability), and rheological (during gluten aggregation, mixing, extension, and leavening) properties were investigated. Finally, bread and fresh pasta were prepared and characterized. Emulsifying activity, stability, and foaming capacity decreased in the presence of CP, whereas foaming stability and water solubility increased. The results on dough rheology highlighted the need to increase the amount of water, and to decrease the mixing and leavening time, to keep an acceptable bread volume. Indeed, 10% CP enrichment led to a product characterized by a similar volume and crumb hardness to the control (wheat flour). Despite the decrease in extensibility caused by CP, it was possible to produce fresh pasta enriched with CP, with the best cooking behavior obtained at a 5% replacement level.

Proximate, Physicochemical, Techno-Functional and Antioxidant Properties of Three Edible Insect (Gonimbrasia belina, Hermetia illucens and Macrotermes subhylanus) Flours

In this study, edible insect flours from Gonimbrasia belina (Mashonzha), Hermetia illucens (black soldier fly larvae) and Macrotermes subhylanus (Madzhulu) were prepared and assessed in terms of proximal, physicochemical, techno-functional and antioxidant properties. The crude protein of the edible insect flours varied between 34.90−52.74%. The crude fat of the insect flours differed significantly (p < 0.05), with H. illucens (27.93%) having the highest crude fat. G. belina was lighter (L*) and yellower (+b*) compared to H. illucens and M. subhylanus, and there was no significant difference (p > 0.05) in the redness (+a*) of the edible insect flours. There were no significant differences (p > 0.05) in foam capacity and foam stability of all three edible insect flours. Moreover, the antioxidant activity against the DPPH radical was low for H. illucens (3.63%), with M. subhylanus (55.37%) exhibiting the highest DPPH radical. Principal component analysis (PCA) was applied to the techno-functional properties and antioxidant indices of the edible insect flours. PC1 accounted for 51.39% of the total variability, while component 2 accounted for 24.71%. In terms of PC1, the FS, OBC and FC were responsible for the major differences in the edible insect flours. The findings revealed that edible insect flours are a good source of antioxidants and can be used as an alternative protein source and a potential novel food additive due to their techno-functional qualities.

Nutritional, Techno-Functional and Structural Properties of Black Soldier Fly (Hermetia illucens) Larvae Flours and Protein Concentrates

Due to their protein content and balanced amino acid profile, edible insects have been described as an excellent alternative protein source to combat malnutrition. As the global population continues to grow, edible insects such as the black soldier fly larvae (BSFL) may contribute to food security. The effect of different protein extraction methods, i.e., alkaline solution and acid precipitation (BSFL-PC1) and extraction with an alkali (BSFL-PC2), on the nutritional, techno-functional, and structural properties of BSFL flours and protein concentrates were studied. The highest protein content (73.35%) was obtained under alkaline and acid precipitation extraction (BSFL-PC1). The sum of essential amino acids significantly increased (p < 0.05) from 24.98% to 38.20% due to the defatting process during extraction. Protein solubility was significantly higher in protein concentrates (85−97%) than flours (30−35%) at pH 2. The emulsion capacity (EC) was significantly higher (p < 0.05) in the protein concentrates (BSFL-PC1 and BSFL-PC2) compared to the freeze-dried and defatted BSFL flours, while the emulsion stability (ES) was significantly (p < 0.05) higher in BSFL-PC1 (100%) compared with BSFL-PC2 (49.8%). No significant differences (p > 0.05) were observed in foaming stability (FS) between freeze-dried and defatted BSFL flours. Fourier transform infrared spectroscopy (FT-IR) analysis revealed distinct structural differences between BSFL flours and protein concentrates. This was supported by surface morphology through scanning electron microscopy (SEM) images, which showed that the protein extraction method influenced the structural properties of the protein concentrates. Therefore, based on the nutritional and techno-functional properties, BSFL flour fractions and protein concentrates show promise as novel functional ingredients for use in food applications.

Chemical composition, energy and nutritional values, digestibility and functional properties of defatted flour, protein concentrates and isolates from Carbula marginella (Hemiptera: Pentatomidae) and Cirina butyrospermi (Lepidoptera: Saturniidae)

Edible insects constitute a potential source of alternative proteins as a food supplement. The present study aimed to investigate the chemical composition, energy and nutritional values, the digestibility and functional properties of Carbula marginella (Thunberg) and Cirina butyrospermi (Vuillet) defatted flour, protein concentrates, and isolates. Carbula marginella has shown the highest content of protein (41.44%), lipid (51.92%), calcium (33.92 mg/100 g) and sodium (185.84 mg/100 g) while the highest contents of carbohydrate (34.54%), ash (4.77%), iron (31.27 mg/100 g), magnesium (150.09 mg/100 g), and potassium (1277 mg/100 g) have been observed for C. butyrospermi. Linoleic (30.23%), palmitic (27.54%), oleic (26.41%) and stearic (8.90%) acids were the most dominant fatty acids found in C. marginella. Cirina butyrospermi was characterized by high levels of oleic (27.01%), stearic (21.02%), linolenic (20.42%), palmitic (13.06%), and linoleic (8.01%) acids. Protein and essential amino acid contents of the protein isolates in both insect species were 1.7–2 times higher than that of their defatted flours. The protein isolate of C. marginella exhibited the highest protein digestibility (87.63%), while the highest fat absorption capacity (8.84 g/g) and foaming capacity (48.40%) have been obtained from the protein isolate of C. butyrospermi. These findings indicate that the protein concentrates and isolates of C. marginella and C. butyrospermi have great potential for industrial applications.

Effect of HHP, Enzymes and Gelatin on Physicochemical Factors of Gels Made by Using Protein Isolated from Common Cricket (Acheta domesticus)

The effect of high hydrostatic pressure (HHP) combined with enzymatic methods or gelatin incorporation in the gelation process of protein isolated from Acheta domesticus was investigated. The results indicate that transglutaminase (TGasa) or glucose oxidase (GOx) enzymes can induce reversible aggregation in dispersions of insoluble protein fractions and increase viscosity in dispersions of soluble fractions, but does not induce gel formation even after HHP treatment; in consequence, enzymatic treatment on cricket protein can be used to increase viscosity but not to form gels. It is technically feasible to obtain gels by adding 2% porcine gelatin to dispersions of protein fractions and subjecting them to HHP. The firmness and syneresis variation values of those gels during storage depended on the protein extracted fraction (insoluble or soluble protein) and on the concentration of protein used. The highest hardness and lowest syneresis was found with the gels obtained from the insoluble fraction at 11 and 15% (w/w) protein concentration. Color difference (ΔE* > 3) appreciable to the naked eye was observed along the storage period and no noticeable pH variations were found after 28 days of storage. Results indicate that new raw materials of interest can be developed for the food industry based on cricket protein isolates, to make high-protein foods which could be applied in a wide variety of different food applications including 3D printing or fat substitution.

Protein extraction protocols for optimal proteome measurement and arginine kinase quantitation from cricket Acheta domesticus for food safety assessment

Insects have been consumed by people for millennia and have recently been proposed as a complementary, sustainable source of protein to feed the world's growing population. Insects and crustaceans both belong to the arthropod family. Crustacean (shellfish) allergies are common and potentially severe; hence, the cross-reactivity of the immune system with insect proteins is a potential health concern. Herein, LC-MS/MS was used to explore the proteome of whole, roasted whole and roasted powdered cricket products. Eight protein extraction protocols were compared using the total number of protein and distinct peptide identifications. Within these data, 20 putative allergens were identified, of which three were arginine kinase (AK) proteoforms. Subsequently, a multiple reaction monitoring MS assay was developed for the AK proteoforms and applied to a subset of extracts. This targeted assay demonstrated that allergen abundance/detectability varies according to the extraction method as well as the food processing method.

LF NMR spectroscopy analysis of water dynamics and texture of Gluten-Free bread with cricket powder during storage

The paper presents the effect of replacing starch (at 2%, 6% and 10%) with cricket powder (CP) on the water behavior studied by the ¹H NMR method, as well as the texture of gluten-free bread during 6-day storage. It was noticed that the bread crumb containing CP has lower water transport rate than the control bread crumb, while concluding that 2% CP stabilizes water transport throughout the entire staling time range. The NMR analyzes showed that the initial T₂₁ values are the higher, the more starch has been replaced with the CP, however, after 6 days of storage, all tested samples are characterized by similar values of the T₂₁ parameter. A decrease in long component of spin-spin relaxation time T₂₂ during storage was also observed. It has been noted that the replacement of starch to 2% and 6% CP causes an increase in the molecular dynamics of water. The less starch present, the greater the potential for bulk molecules to move. The observed changes at the molecular level resulted in macroscopic changes in the texture of the bread. After analyzing the hardness parameter of the tested breads, it was found that on the day of baking, bread without the addition of CP had significantly higher values of this parameter than breads with CP. For the sample without CP, the highest increase in total hardness change (123.93%) was noted during storage, which indicates the fastest texture change process. Based on the results obtained, it can be concluded that the use of cricket powder to enrich gluten-free bread can not only improve the nutritional value, but also effectively delay the process of bread staling.

Contributions of protein and milled chitin extracted from domestic cricket powder to emulsion stabilization

Interfacial and emulsifying properties of fractionated cricket powder were assessed to identify whether emulsification properties originate from protein or chitin particles. Fractions extracted in alkaline water, containing high protein and mineral contents, increased the surface pressure of heptane-water interfaces with near-saturation equilibrium surface pressure of 31 mN/m. Dynamic surface pressure profiles indicated adsorption of protein clusters to the interface. Emulsification capacity of protein fraction was 50% greater than that of the source cricket flour, although oil-in-water emulsions prepared with 1-2% (w/w) protein fraction formed a cream layer within one day of storage. Emulsified layers persisted for up to 20 days, and light scattering measurements described a stable population with surface-volume-mean diameter of approximately 3 μm. Chitin-rich fractions milled to a particle size of 0.5-200 μm contributed negligible surface pressure, and its emulsification capacity was 5% of the value for the source cricket flour. Emulsions prepared with chitin-rich fractions coexisted with an unstable precipitate layer comprising 60% of the added solid, which was attributed to larger particles with poor emulsifying capability. Stable chitin-stabilized emulsion phases were resistant to creaming, yet volume-mean droplet diameter surpassed 50 μm within 24 h of storage. Both protein and chitin fractions have emulsifying capabilities but would require further processing or secondary additives to achieve desirable storage stability.

Protein quality and physicochemical properties of commercial cricket and mealworm powders

The pressing need for protein supply growth gives rise to alternative protein sources, such as insect proteins. Commercial cricket and mealworm powders were examined for their protein quality, surface charge and functional attributes. Both insect powders had similar proximate compositions with protein and ash contents of ~ 66% db (dry weight basis) and 5% db, respectively, however cricket powder contained more lipid (16.1%, db) than mealworm powder (13.7%, db). Mealworm protein had an amino acid score of 0.71 and was first limiting in lysine, whereas cricket protein was first limiting in tryptophan with an amino acid score of 0.85. In vitro protein digestibility values of 75.7% and 76.2%, and in vitro protein digestibility corrected amino acid scores of 0.54 and 0.65, were obtained for mealworm and cricket powders, respectively. Zeta potential measurements gave isoelectric points near pH 3.9 for both insect powders. Mealworm and cricket powders had water hydration capacities of 1.62 g/g and 1.76 g/g, respectively, and oil holding capacities of 1.58 g/g and 1.42 g/g, respectively. Both insect proteins had low solubility (22-30%) at all pHs (3.0, 5.0, and 7.0) measured. Cricket powder had a foaming capacity of 82% and foam stability of 86%, whereas mealworm powder was non-foaming. Values for commercial pea and faba bean protein concentrates were reported for comparative purposes. The insect proteins had similar protein quality as the pulse proteins and had higher solubility at pH 5.0 but were much less soluble at pH 7.0.

Food Proteins: Technological, Nutritional, and Sustainability Attributes of Traditional and Emerging Proteins

Protein is an essential macronutrient and a key structural component of many foods. The nutritional and technological properties of food protein ingredients depend on their source, extraction and purification, modification during food manufacture, and interactions with other food components. In addition to covering these elements, this review seeks to highlight underappreciated aspects of protein environmental sustainability and explores the potential of cultured meat and insect-derived proteins.

Potential of Extracted Locusta Migratoria Protein Fractions as Value-Added Ingredients

Although locusts can be sustainably produced and are nutrient rich, the thought of eating them can be hard to swallow for many consumers. This paper aims to investigate the nutritional composition of Locusta migratoria, including the properties of extracted locust protein, contributing to limited literature and product development opportunities for industry. Locusts sourced from Dunedin, New Zealand, contained a high amount of protein (50.79% dry weight) and fat (34.93%), which contained high amounts of omega-3 (15.64%), creating a desirably low omega-3/omega-6 ratio of 0.57. Three protein fractions including; insoluble locust fraction, soluble locust fraction, and a supernatant fraction were recovered following alkali isoelectric precipitation methodology. Initially, proteins were solubilised at pH 10 then precipitated out at the isoelectric point (pH 4). All fractions had significantly higher protein contents compared with the whole locust. The insoluble protein fraction represented 37.76% of the dry weight of protein recovered and was much lighter in colour and greener compared to other fractions. It also had the highest water and oil holding capacity of 5.17 mL/g and 7.31 mL/g, possibly due to larger particle size. The high supernatant yield (56.60%) and low soluble protein yield (9.83%) was unexpected and could be a result of experimental pH conditions chosen.