Effects of High Hydrostatic Pressure assisted degreasing on the technological properties of insect powders obtained from Acheta domesticus & Tenebrio molitor

Effects of high hydrostatic pressure processing on the physicochemical properties, functional characteristics, and antioxidant activity of silkworm pupae protein

With the rising demand for sustainable proteins, edible insects such as silkworm pupae are gaining recognition for their high-quality protein and essential nutrients. Advanced technologies like high hydrostatic pressure (HHP) processing have the potential to enhance the functional properties of insect proteins. This study investigated the application of HHP to silkworm pupa protein, focusing on its effects on physicochemical properties, functional characteristics, and bioactivity. HHP treatments at 400 and 600 MPa significantly enhanced emulsifying and foaming capacities, as well as antioxidant activity. Furthermore, HHP-assisted extraction facilitated protein unfolding and increased the exposure of hydrophobic groups on the protein surface, which likely contributed to improvements in protein solubility and antioxidant function. These findings provide valuable insights into the potential of HHP to enhance the quality of edible insect proteins for food applications.

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.

Application of edible insects to food products: A review on the functionality, bioactivity and digestibility of insect proteins under high-pressure/ultrasound processing

Edible insect products are recognized for their high-quality protein content and an array of essential nutrients, including minerals and fatty acids. As the demand for sustainable protein sources grows, insect-based foods are gaining attention as a viable solution to help address global food security. Emerging technologies including high-pressure processing (HPP) and ultrasound (US) have the potential to influence the key functional properties of insect proteins-such as solubility, gelling ability, foamability, and emulsifying capacity-making them more suitable for incorporation into various food products. Additionally, the physicochemical properties and functionality of these proteins can be altered by digestive processes. This review focuses on the physicochemical and functional properties, as well as the biological activities, of edible insects modified by HHP and US technologies. It also explores, for the first time, how digestion impacts the quality and biological activities of insect-based products.

Systematic preparation of animal-derived glycosaminoglycans: Research progress and industrial significance

Impurities and isomerized polysaccharides affect the analytical accuracy of glycosaminoglycans (GAGs) structure and bioactivity, hindering their application in food and medicine. Preparing homogeneous GAGs components is essential for exploring structure-potency relationships and facilitating industrial production. This review primarily summarizes research on animal-derived GAGs preparation over the past five years, standardizing the preparation process into four operational units: pre-extraction treatment, extraction of crude polysaccharides, refinement of crude polysaccharides, and separation of GAGs components. Analyzed for scientific research and industrial production, the principles and application conditions of traditional means and novel techniques to preparing GAGs are comprehensively emphasized, exploring the effects of different treatments on biological activity and structure. Current challenges and development trends are illuminated. This review aims to lay a foundation for the in-depth study of GAGs structure, bioactivity, and function, providing theoretical references for the comprehensive utilization of animal raw materials and the development of animal polysaccharide deep-processing industries.

Extraction, characterization, and use of edible insect oil - A review

Population growth is driving the search for new food sources, including entomophagy, i.e., a diet based on edible insects. Insect powder are rich in essential fatty acids, minerals, vitamins, and bioactive compounds such as antioxidant phenolics. The technologies for extracting oil from insects must be efficient to guarantee high yields. This oil due to its favorable nutritional profile, and lower cost, can be a viable alternative to vegetable and fish oils. Although common in some cultures, the consumption of insects faces resistance in others due to its association with dirt. Efforts are being made to scientifically demonstrate the safety and nutritional benefits of insects as well as their sustainability as a food source. This first review of insect oils focuses on presenting their different characteristics and encouraging the production and use of these products in the food, pharmaceutical, or cosmetics industries.

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.

Quality assessment of yellow mealworm (Tenebrio molitor L.) powders processed by pulsed electric field and convective drying

Edible insects offer opportunities for food production, as they are an interesting source of many nutrients. In this study, the effect of pulsed electric field (PEF) and convective drying on the chemical composition with emphasizing the fat properties as well as physical, techno-functional, and thermal properties of yellow mealworm powders was investigated. The chemical composition of the yellow mealworm powders differed by PEF. When PEF was applied at 20 and 40 kJ/kg, the moisture, ash, and protein content were significantly lower, while the fat extraction yield significantly increased compared to the control sample. Furthermore, the fat extracted from these samples was characterized by a higher proportion of saturated and monounsaturated fatty acids as well as a higher thrombogenicity index, which is not beneficial from a nutritional point of view. After treatment with PEF at 5 kJ/kg, the powder was the lightest, redness and yellowness. Moreover, the highest hygroscopicity, water activity, and water and oil binding capacity for this powder were determined. The results revealed that yellow mealworm powders are a good source of macronutrients and exhibit beneficial techno-functional properties, nevertheless, the drawback is their high cohesiveness (1.27-1.44), which can be difficult to apply under industrial conditions.

Changes of structural characteristics, functional properties and volatile compounds of Tenebrio molitor larvae protein after sustainable defatting process: Influence of the different volume ratios of n-hexane to ethanol

This work aimed to study the effect of defatting via the mixture of n-hexane and ethanol under different volume ratio on the changes of structural characteristics, functional properties and volatile compounds of Tenebrio molitor larvae protein (TMLP). The results showed that 1:0.6 vol ratio of n-hexane to ethanol rendered the highest defatting rate (P < 0.05), as well as led to the highest EAA/AA contents, sulfhydryl contents, surface hydrophobicity, solubility, water/oil holding capacities and emulsifying properties of TMLP (P < 0.05). However, higher volume ratio of n-hexane to ethanol led to negative impacts on functionalities of TMLP. Moreover, the contents of aldehydes and hydrocarbons which rendered off-flavour to TMLP significantly decreased with the increasing volume ratio of n-hexane to ethanol (P < 0.05), while the contents of pleasure flavour (hydrocarbons and ester compounds) were obviously enhanced. This study provides an eco-friendly defatting method on the processing of TMLP with superior quality attributes.

Quality evaluation of house cricket flour processed by electrohydrodynamic drying and pulsed electric fields treatment

House crickets are expected to play a significant role in the future food sector. Electrohydrodynamic (EHD) drying offers an environmentally friendly alternative to conventional drying methods. Pulsed electric fields (PEF) is a non-thermal process that facilitates conventional processes. EHD was applied to house crickets with and without PEF pretreatment, and the effect of PEF and EHD on the quality of the insects was evaluated. PEF pretreatment positively affected the oven drying at 60 °C by reducing its duration and thus decreasing the energy consumption by 14.22%. Moisture removal of EHD was not sufficient to replace oven drying, but when combined with oven drying, the overall energy consumption was reduced by >50%. PEF processing also increased the protein solubility (53.07% higher than the respective control) and antioxidant activity (24.05% higher than the respective control) of the oven-dried samples and reduced the histamine content of the EHD-dried samples (25.87% lower than the respective control).

Chitosan Alginate Nanoparticles of Protein Hydrolysate from Acheta domesticus with Enhanced Stability for Skin Delivery

This study aimed to develop chitosan alginate nanoparticles (CANPs) for enhanced stability for dermal delivery of protein hydrolysate from Acheta domesticus (PH). CANPs, developed using ionotropic pre-gelation followed by the polyelectrolyte complex technique, were characterized for particle size, polydispersity index (PDI), and zeta potential. After the incorporation of PH into CANPs, a comprehensive assessment included encapsulation efficiency, loading capacity, morphology, chemical analyses, physical and chemical stability, irritation potential, release profile, skin permeation, and skin retention. The most optimal CANPs, comprising 0.6 mg/mL sodium alginate, 1.8 mg/mL calcium chloride, and 0.1 mg/mL chitosan, exhibited the smallest particle size (309 ± 0 nm), the narrowest PDI (0.39 ± 0.01), and pronounced negative zeta potential (-26.0 ± 0.9 mV), along with an encapsulation efficiency of 56 ± 2%, loading capacity of 2.4 ± 0.1%, release of 40 ± 2% after 48 h, and the highest skin retention of 12 ± 1%. The CANPs induced no irritation and effectively enhanced the stability of PH from 44 ± 5% of PH remaining in a solution to 74 ± 4% after three-month storage. Therefore, the findings revealed the considerable potential of CANPs in improving PH stability and skin delivery, with promising applications in cosmetics and related fields.

Effect of gamma-ray and electron-beam irradiation on the structural changes and functional properties of edible insect proteins from Protaetia brevitarsis larvae

Edible insects are regarded as future food sources to replace traditional livestock proteins. However, insect proteins have poor processing properties owing to various structural limitations. We investigated the structure of Protaetia brevitarsis larvae proteins modified by irradiation, and analyzed their resulting processing abilities. Following irradiation with gamma rays and electron beams, the ratio of parallel β-sheets to β-turns changed significantly, and changes in the tertiary protein structures were also confirmed. The polydispersity indices of the proteins remained relatively constant following irradiation, although the zeta potential and mean diameter changed. Furthermore, the pH, protein solubility, surface hydrophobicity, foaming capacity, and emulsion stability were higher than those of the control, whereas the viscosity and foaming stability were lower. Thus, gamma ray and electron beam irradiation clearly lead to changes in the structures of edible insect proteins and improves their processing properties, promoting the industrial utilization of such proteins in the food industry.

Quality and staling characteristics of white bread fortified with lysozyme-hydrolyzed mealworm powder (Tenebrio molitor L.)

Edible insects have a low environmental impact but are rich in nutrients and have been promoted as alternative protein sources. However, adding insect flour to bread negatively affects the overall quality, especially loaf volume and textural properties. Furthermore, relevant studies on chitin are limited. Therefore, this study examined chitin hydrolysis using lysozymes to enhance the quality characteristics in defatted mealworm (Tenebrio molitor L.) powder (DF-M)-supplemented bread. The chitin hydrolysis degree by lysozymes was evaluated using the 3,5-dinitrosalicylic acid assay and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. The amount of chitin oligomers increased with time, and no significant difference in the hydrolysis efficiency between water and 400 mM acetate buffer was observed. Enzymatic hydrolysis improved the DF-M water- and oil-binding and antioxidant capacities. In addition, chitin hydrolysis increased the volume and softened the texture of white bread. In particular, bread supplemented with DF-M hydrolyzed for 4 h at 10 % had the highest moisture content among the mealworm-added bread groups during storage for 5 days. Moreover, sensory evaluation showed a positive effect of chitin hydrolysis on acceptability. Our findings indicate that chitin hydrolysis can improve the quality of bread containing insect additives. In conclusion, this study provides novel insights into producing high-quality and functional bakery products from edible insects by the enzymatic hydrolysis of edible insect powders and could expand the applications of edible insects as food ingredients.

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.

The Review of Cooking, Drying, and Green Extraction Methods on General Nutritional Properties of Mealworms and Locusts

The processing of edible insects as an alternative source of nutrition may be a key driver in the development of a sustainable food and feed system. This review will study two industrial types of insects-mealworms and locusts-and summarize evidence related to the impact of processing on their micro- and macronutritional characteristics. The focus will be on their potential use as food for human consumption as opposed to animal feed. Literature has indicated that these two insects have the potential to provide protein and fat qualities comparable to or better than traditional mammalian sources. For example, mealworms-the larval form of the yellow mealworm beetlepossess a higher fat content, while adult locusts are rich in fibers, especially chitin. However, due to the different matrix and nutrient compositions, the processing of mealworms or locusts at a commercial scale needs to be tailored to minimize nutritional loss and maximize cost efficiency. The stages of preprocessing, cooking, drying, and extraction are the most critical control points for nutritional preservation. Thermal cooking applications such as microwave technology have demonstrated promising results, but the generation of heat may contribute to a certain nutritional loss. In an industrial context, drying using freeze dry is the preferred choice due to its uniformity, but it can be costly while increasing lipid peroxidation. During the extraction of nutrients, the use of green emerging technologies such as high hydrostatic pressure, pulsed electric field, and ultrasound may provide an alternative method to enhance nutrient preservation.

Graphical Abstract

Tenebrio molitor as a Clean Label Ingredient to Produce Nutritionally Enriched Food Emulsions

Tenebrio molitor flour, a sustainable source of protein and bioactive compounds, was used as a clean label ingredient in order to reformulate a commercial hummus sauce, replacing egg yolk and modified starch, improving its nutritional quality. For this purpose, the impact of different concentrations of insect flour on the sauce was studied. Rheology properties, texture profile analysis, and the microstructure of the sauces were analyzed. Nutritional profile analysis was carried out, as well as bioactivity, namely the total phenolic content and the antioxidant capacity. Sensory analysis was conducted to determine the consumer's acceptance. At low concentrations (up to 7.5% of T. molitor flour) the sauce structure remained practically unchanged. However, for higher additions of T. molitor (10% and 15%), a loss of firmness, adhesiveness and viscosity was observed. Structure parameters such as elastic modulus (G') at 1 Hz of the sauces with 10% and 15% were significantly lower than the commercial sauce, indicating a loss of structure caused by Tenebrio flour incorporation. Although the formulation with 7.5% T. molitor flour was not the best rated in the sensory analysis, it showed a higher antioxidant capacity compared to the commercial standard. In addition, this formulation also presented the highest concentration in total phenolic compounds (16.25 mg GAE/g) and significantly increased the content of proteins (from 4.25% to 7.97%) and some minerals, compared to the standard.

Insects as Feed for Companion and Exotic Pets: A Current Trend

The objective of this review was to carry out a comprehensive investigation of the benefits of incorporating insects as a pet food ingredient and the implications this can have in determining a market demand for insect-based pet foods. Black soldier fly larvae (Hermetia illucens), mealworm larvae (Tenebrio molitor) and adult house crickets (Acheta domesticus) are currently used in pet food. These insects are widely fed to exotic pets, mainly in whole, live or dehydrated formats. They are also incorporated as meal or fat and are offered to cats and dogs as dry or wet food and treats. Scientific studies about the use of insects for dog and cat feed are scarce. Most studies are in dogs. Research shows that insect nutrients, mainly amino acids, have high digestibility, are beneficial to health, do not have any detrimental effect on the gut microbiota and are accepted by dogs. In several countries, insects are approved for use in pet food and commercialization has spread throughout the world. Pet owners are willing to try foods made with insect meal for their pets. In conclusion, the use of insects in pet food is a reality that is taking on more and more prominence.

Edible Insects’ Transformation for Feed and Food Uses: An Overview of Current Insights and Future Developments in the Field

The integration of insect-derived extracts in feed and food products has become a field of growing interest in recent years. In this review, we collect different studies carried out on edible insects’ transformation processes and focus on the various treatment operations, extraction technologies, and solvents used in different processing steps. We include an overview of current insights into the different steps of the transformation process: insect reception, killing methods, pretreatments, storage, delipidation, protein extraction, as well as chitin and chitosan extraction. Finally, we reflect on the most important future challenges of this sector.

Protein by-products: Composition, extraction, and biomedical applications

Significant upsurge in animal by-products such as skin, bones, wool, hides, feathers, and fats has become a global challenge and, if not properly disposed of, can spread contamination and viral diseases. Animal by-products are rich in proteins, which can be used as nutritional, pharmacologically functional ingredients, and biomedical materials. Therefore, recycling these abundant and renewable by-products and extracting high value-added components from them is a sustainable approach to reclaim animal by-products while addressing scarce landfill resources. This article appraises the most recent studies conducted in the last five years on animal-derived proteins' separation and biomedical application. The effort encompasses an introduction about the composition, an overview of the extraction and purification methods, and the broad range of biomedical applications of these ensuing proteins.

Effect of High Hydrostatic Pressure Intensity on Structural Modifications in Mealworm (Tenebrio molitor) Proteins

Processing edible insects into protein extracts may improve consumer acceptability. However, a better understanding of the effects of food processing on the proteins is needed to facilitate their incorporation into food matrices. In this study, soluble proteins from Tenebrio molitor (10% w/v) were pressurized using high hydrostatic pressure (HHP) at 70–600 MPa for 5 min and compared to a non-pressurized control (0.1 MPa). Protein structural modifications were evaluated using turbidity measurement, particle-size distribution, intrinsic fluorescence, surface hydrophobicity, gel electrophoresis coupled with mass spectrometry, and transmission electron microscopy (TEM). The observed decrease in fluorescence intensity, shift in the maximum emission wavelength, and increase in surface hydrophobicity reflected the unfolding of mealworm proteins. The formation of large protein aggregates consisting mainly of hexamerin 2 and ⍺-amylase were confirmed by protein profiles on gel electrophoresis, dynamic light scattering, and TEM analysis. The typical aggregate shape and network observed by TEM after pressurization indicated the potential involvement of myosin and actin in aggregate formation, and these were detected by mass spectrometry. For the first time, the identification of mealworm proteins involved in protein aggregation phenomena under HHP was documented. This work is the first step in understanding the mealworm protein–protein interactions necessary for the development of innovative insect-based ingredients in food formulations.

Novel Insights on the Sustainable Wet Mode Fractionation of Black Soldier Fly Larvae (Hermetia illucens) into Lipids, Proteins and Chitin

The black soldier fly larvae (BSFL) is a sustainable ingredient for feed applications, biofuels, composite materials and other biobased products. Processing BSFL to obtain lipid and protein fractions with enhanced functional properties as a suitable replacement for conventional feed ingredients has gained considerable momentum. In this regard, a novel and sustainable wet mode fractionation (WMF) scheme for BSFL was explored. Fresh BSFL were steam blanched and pulped to obtain BSFL juice and juice press cake. Subsequent treatment of BSFL juice employing homogenization or enzyme incubation and further centrifugation resulted in the obtention of four different BSFL fractions (Lipid—LF; Cream—CF; Aqueous—AF; and Solid—SF). Total energy consumption for a batch BSFL (500 g) WMF process was 0.321 kWh. Aqueous and solid fractions were the predominant constituents of BSFL juice. Lauric acid (44.52–49.49%) and linoleic acid (19.12–20.12%) were the primary fatty acids present in BSFL lipids. Lipid hydrolysis was observed in lipids belonging to the solid (free fatty acids > triacylglycerides) and cream fractions. Aqueous fraction proteins (ctrl) displayed superior emulsion stability and foam capacity than other treatments. Juice press cake retained 60% of the total chitin content and the rest, 40%, was found in the solid fraction (ctrl). The material distribution of principal constituents in different fractions of the WMF process and amino acid profile was elucidated. Overall, the versatile WMF process proposed in this study involves simple unit operations to obtain functional ingredients from BSFL, which can be further explored by researchers and industry stakeholders.

Detection of Authenticity and Quality of the Turkish Delights (Lokum) by Means of Conventional and Fast Field Cycling Nuclear Magnetic Resonance Relaxometry

Turkish delights (lokum) are traditional confectionery products that contain mainly sucrose as the sugar source and starch as the gelling agent. However, manufacturers sometimes might prefer to use corn syrup instead of sucrose to decrease the cost. This jeopardizes the originality of Turkish delights and leads to production of adulterated samples. In this study, Turkish delights were formulated using sucrose (original sample) and different types of corn syrups (SBF10, SCG40, and SCG60). Results clearly indicated that corn-syrup-containing samples had improved textural properties and were less prone to crystallization. However, this case affected authenticity of the products negatively. Both time domain nuclear magnetic resonance (TD NMR) and fast field cycling nuclear magnetic resonance (FFC NMR) techniques were found to be effective to discriminate the original samples from the corn-syrup-containing samples. In addition, quantitative analysis of FFC NMR showed that, apart from the rotational motions, molecules in Turkish delights (mainly water and also sugar molecules) undergo two types of translational dynamics.

A Review on the Extraction and Processing of Natural Source-Derived Proteins through Eco-Innovative Approaches

In addition to their nutritional and physiological role, proteins are recognized as the major compounds responsible for the rheological properties of food products and their stability during manufacture and storage. Furthermore, proteins have been shown to be source of bioactive peptides able to exert beneficial effects on human health. In recent years, scholarly interest has focused on the incorporation of high-quality proteins into the diet. This fact, together with the new trends of consumers directed to avoid the intake of animal proteins, has boosted the search for novel and sustainable protein sources and the development of suitable, cost-affordable, and environmentally friendly technologies to extract high concentrations of valuable proteins incorporated into food products and supplements. In this review, current data on emergent and promising methodologies applied for the extraction of proteins from natural sources are summarized. Moreover, the advantages and disadvantages of these novel methods, compared with conventional methods, are detailed. Additionally, this work describes the combination of these technologies with the enzymatic hydrolysis of extracted proteins as a powerful strategy for releasing bioactive peptides.