Insect lipid profile: aqueous versus organic solvent-based extraction methods

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.

Exploring the potential of Hermetia illucens larvae extracts: A promising approach for dermocosmetic formulations

Globally, the yearly disposal of 1.3 billion tonnes of food raises environmental and public health concerns. Black soldier fly (BSF) larvae present a sustainable solution, converting organic waste into nutrient-rich biomass. The extracted oil from BSF larvae, rich in fatty acids (FA), offers an eco-friendly alternative for the cosmetic industry. In this study, larvae sourced from a Portuguese company were fed olive pomace, a by-product of olive oil production. The lipidic sample extracted revealed a composition high in oleic acid, valuable for cosmetics. Investigating the biological activity of lipid extractions from larvae fed with olive pomace is a novel approach. Notably, the n-hexane ultrasound-assisted extraction method demonstrated potent antioxidant properties, and some extracts displayed antimicrobial activity. Five non-cytotoxic extracts; three with no relevant activity (IC50 from 236 to >400 μg/mL). These findings highlight BSF larvae as an environmentally friendly source of fatty acids, offering promising alternatives for diverse applications.

Extraction and application of lipids from edible insects

Research on new food sources is a worldwide challenge due to the constant increase in the global population. In this scenario, insects and bug based products have been investigated as feasible food alternatives. They are nutritionally healthy and environmentally sustainable. Eating insects (entomophagy) or utilizing their macronutrients in food formulations can efficiently solve the demand for nutritious food. The benefits of insect-based foods are reported in the literature, mainly because they are viable sources of fat (∼38%) and proteins (∼68%). Fats and oils are recognized as essential nutrients in human nutrition, as they provide a concentrated source of energy and act as structural components of cell membranes and signaling pathways. The high levels of fats/oils of edible insects open the perspective in the food industry to be used as ingredients in the enrichment of several products, such as cookies, biscuits, butter, and margarine, among others, thus contributing to consumer acceptance. Insect fat/oil can be obtained using extraction techniques, such as solvent and supercritical CO2 methods. The method depends on the insect species, fat/oil yield, and process costs. Thus, this review aims to provide current information on the consumption, application, and extraction of edible insect oils.

Microorganism Contribution to Mass-Reared Edible Insects: Opportunities and Challenges

The interest in edible insects' mass rearing has grown considerably in recent years, thereby highlighting the challenges of domesticating new animal species. Insects are being considered for use in the management of organic by-products from the agro-industry, synthetic by-products from the plastics industry including particular detoxification processes. The processes depend on the insect's digestive system which is based on two components: an enzymatic intrinsic cargo to the insect species and another extrinsic cargo provided by the microbial community colonizing-associated with the insect host. Advances have been made in the identification of the origin of the digestive functions observed in the midgut. It is now evident that the community of microorganisms can adapt, improve, and extend the insect's ability to digest and detoxify its food. Nevertheless, edible insect species such as Hermetia illucens and Tenebrio molitor are surprisingly autonomous, and no obligatory symbiosis with a microorganism has yet been uncovered for digestion. Conversely, the intestinal microbiota of a given species can take on different forms, which are largely influenced by the host's environment and diet. This flexibility offers the potential for the development of novel associations between insects and microorganisms, which could result in the creation of synergies that would optimize or expand value chains for agro-industrial by-products, as well as for contaminants.

Macrotermes subhylanus flour inclusion in biscuits: Effects on nutritional, sensorial and microbial characteristics

As the world's population expands, edible insects have been proposed as a food source that might address issues related to nutrition, health, the environment, and the economy. This study aimed to create a novel biscuit by adding Macrotermes subhylanus (M. Subhylanus) flour to wheat flour in various concentrations (5,10, 15 and 20 %). The moisture content of the insect composite flours varied between 6.83 % and 7.76 %, whereas the moisture content of the biscuits ranged from 2.86 % to 7.90 %. A significant difference (p < 0.05) was noted in the protein content of both the composite flours and biscuits as the concentration of insect flour increased, with values ranging from 15.03 % to 21.52 % for the flours and 17.38 % to 20.63 % for the biscuits. The lightness (L*) of the composite flours significantly decreased (p < 0.05) with higher additions of edible insect flour, whereas the redness (a*) and yellowness (b*) attributes did not show any statistical differences (p > 0.05). The biscuits were generally darker than the composite flours, as indicated by substantially lower L* values. The water activity of the biscuits was between 0.44 and 0.67. Sensory evaluation revealed that the substitution level (up to 15 %) is ideal for preparing acceptable insect-based biscuits. The panellist perceived no significant differences (p > 0.05) in terms of the texture between the insect-enriched biscuits and the control, except for MZ-20. The absence of pathogenic microogranisms in all baked biscuits containing edible insect flour highlights the effectiveness of heat treatment, ensuring that the biscuits meet microbiological safety guidelines. Additionally, Macrotermes subhylanus flour shows promise as a novel functional ingredient for the food industry.

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.

Intensification of the SFE Using Ethanol as a Cosolvent and Integration of the SFE Process with sc-CO2 Followed by PLE Using Pressurized Ethanol of Black Soldier Fly (Hermetia illucens L.) Larvae Meal-Extract Yields and Characterization

The objective of this research was to investigate and compare the results obtained in the intensification and integration of (sc-CO2) under different pressure conditions (25 and 30 MPa) at 60 °C. When intensifying the process, ethanol (10%) was used as a co-solvent (sc-CO2 + EtOH). In the process integration, black soldier fly larvae flour, defatted via supercritical extraction (SFE), was the raw material for pressurized liquid extraction (PLE) using ethanol as solvent. The extract yields, fatty acid profile, free fatty acids, triacylglycerols (TAGs), oxidative stability, and nutritional quality of the oil obtained using sc-CO2 + EtOH were evaluated. The composition of bioactive compounds (carotenoids, acidity, antioxidant compounds, tocopherols, and phospholipids) was determined in both extracts. The yields of the extracts were different by 32.5 to 53.9%. In the extracts obtained with sc-CO2 + EtOH (10%), the predominant fatty acids were oleic, palmitic, and linoleic, with considerable levels of desirable fatty acids (DFA), tocopherols, and phospholipids. The nutritional indices showed good values for polyunsaturated and saturated fatty acids (PUFAs/SFAs), above 0.45%. Extracts from larvae meal defatted with SFE showed carotenoids, phenolic compounds, and antioxidant activity. HPTLC and HPLC analyses indicated the presence of amino acids, sugars, phenolics, and organic acids in their composition. This study revealed that the supercritical fluid extraction (SFE) process, or its conditions, can modify the fatty acid composition and the presence of minor bioactive compounds in the obtained extracts.

Determination of Triacylglycerol Composition in Mealworm Oil (Tenebrio molitor) via Electrospray Ionization Tandem Mass Spectrometry with Multiple Neutral Loss Scans

Mealworms (Tenebrio molitor) have been used as an alternative source of proteins and lipids. Triacylglycerols (TAGs) are major sources of energy and have been used to provide essential fatty acids. They are also the main components of mealworm oil, and their composition and content are extensively linked to its physical and chemical properties. However, because of the complexity of TAG molecules, their identification and quantitation are challenging. This study employed electrospray ionization tandem mass spectrometry (ESI-MS/MS) with multiple neutral loss scans (NLS) to analyze the TAG composition and content in mealworm oil. Identifying and quantifying TAGs using ESI-MS/MS in combination with multiple NLS was an efficient way to improve accuracy and timeliness. For the accurate quantification of TAGs, isotopic deconvolution and correlation factors were applied. A total of 57 TAGs were identified and quantified: C52:2 (16:0/18:1/18:1) (1549.4 nmol/g, 18.20%), C52:3 (16:0/18:1/18:2) (1488.1 nmol/g, 17.48%), C54:4 (18:1/18:1/18:2) (870.1 nmol/g, 10.23%), C54:6 (18:1/18:2/18:2) (659.8 nmol/g, 7.76%) and C52:4 (16:0/18:2/18:2) (600.5 nmol/g, 7.06%), which were the most abundant TAGs present in the mealworm oil. The fundamental properties of mealworm oil, including its degree of oxidation, nutritional effect and physical properties, were elucidated.

Recent advances in edible insect processing technologies

Alternative foods have emerged as one of the hot research topics aiming at alleviating food shortage. Insects are one of the alternative foods due to their rich nutrients. Processing is a critical step to develop insect foods, while there is a lack of comprehensive reviews to summarize the main studies. This review aims to demonstrate different processing methods in terms of their impact on insect nutrition and their potential risks. Heat treatments such as boiling and blanching show a negative effect on insect nutrition, but essential to assure food safety. Insects treated by high-pressure hydrostatic technology (HPP) and cold atmospheric pressure plasma (CAPP) can achieve a similar sterilization effect but retain the nutritional and sensory properties. Drying is a practical processing method for industrial insect production, where oven drying serves as a cost-effective method yielding products comparable in quality to freeze-dried ones. In terms of extraction technology, supercritical carbon dioxide and ultrasound-assisted technology can improve the extraction efficiency of proteins and lipids from insects, enhance the production of composite insect-fortified foods, and thus facilitate the development of the insect food industry. To address the widespread negative perceptions and low acceptance towards insect foods among consumers, the primary development direction of the insect food industry may involve creating composite fortified foods and extracting insect-based food components.

Characterization of mixed-component oleogels: Beeswax and glycerol monostearate interactions towards Tenebrio Molitor larvae oil

Edible insects are attracting attention as an alternative food due to their excellent production efficiency, lower carbon consumption, and containing high protein. Tenebrio Molitor larvae (TM), one of the approved edible insects worldwide, contain more than 30 % fat content consisting of 70 % unsaturated fatty acids, and particularly high phospholipids. Most of the research has focused on the utilization of proteins, and there are few studies using oils from TM. Therefore, in this study, to expand the utilization of TM oil in food applications, the oleogel was prepared with TM oil fortified by the incorporation of beeswax (BSW) and glycerol monostearate (GMS), and their structure, rheological and thermal properties were evaluated. The interaction between BSW and GMS contributed to the strength of the oleogel structure. The addition of GMS or the increase of the gelator concentrations resulted in increasing the melting point, which is consistent with the observed increase in viscoelasticity. As the temperature increased, the solid fat content decreased. The result of FT-IR suggests that TM oil is physically solidified without changing chemical composition through oleogelation. This study suggests a new processing direction for edible insects by confirming the rheological, thermal, and physicochemical characteristics of TM oil-based oleogel.

Bioactive compounds and biological activity in edible insects: A review

New strategies to combat hunger are a current and urgent demand. The increase in population has generated a high demand for products and services that affect food production, cultivation areas, and climate. Viable and sustainable alternative sources have been sought to meet food quality requirements. In this context, edible insects are a good source of macro-nutrients, and bioactive compounds confer biological properties that improve their nutritional aspects and benefit human health. This review aims to present the benefits and contributions of edible insects from the point of view of the biological contribution of macronutrients, and bioactive compounds, as well as consider some anti-nutritional aspects reported in edible insects. It was found that insects possess most of the macronutrients necessary for human life and are rich in bioactive compounds commonly found in plants. These bioactive compounds can vary significantly depending on the developmental stage, diet, and species of edible insects. However, they also contain phytochemicals in which anti-nutrients predominate, which can adversely affect humans with allergenic reactions or reduced nutrient viability when consumed in high amounts or for prolonged periods. Hydrocyanide, oxalates, soluble oxalate, and phytate are the most studied anti-nutrients. However, the doses at which they occur are far below the limits in foods. In addition, anti-nutrient levels decrease significantly in processing, such as oven-drying and defatting methods. However, there are few studies, so more trials are needed to avoid generalizing. Therefore, edible insects can be considered complete food.

An analysis of emerging food safety and fraud risks of novel insect proteins within complex supply chains

Food consumption play a crucial role in human life, yet conventional food production and consumption patterns can be detrimental to the environment. Thus, research and development has been directed towards alternative proteins, with edible insects being promising sources. Edible insects have been recognised for their sustainable benefits providing protein, with less emission of greenhouse gas, land and water usage compared to sources, such as beef, chicken, and dairy products. Among the over 2000 known edible insect species, only four, namely yellow mealworm (Tenebrio molitor), migratory locust/grasshopper (Locusta migratoria), grain mould beetle, also known as lesser mealworm which is a larval form of Alphitobius diaperinus (from the family of Tenebrionidae of darkling beetles) and house cricket (Acheta domesticus), are currently authorised in specific products through specific producers in the EU. The expansion of such foods into Western diets face challenges such as consumer barriers, gaps in microbiological and chemical safety hazard data during production and processing, and the potential for fraudulent supply chain activity. The main aim of this study was to map the supply chain, through interviews with personnel along the supply chain, coupled with searches for relevant publications and governmental documents. Thus, the main potential points of food safety and fraud along the edible insect supply chain were identified. Feed substrate was identified as the main area of concern regarding microbiological and chemical food safety and novel processing techniques were forecast to be of most concern for future fraudulent activity. Despite the on-going authorisation of insect species in many countries there are substantial food safety and authenticity information gaps in this industry that need to be addressed before edible insects can be viewed as a safe and sustainable protein sources by Western consumers.

Nutritional Value of Banded Cricket and Mealworm Larvae

Insect farming is more ecological than traditional animal farming, as it requires less water and contributes to lower greenhouse gas emissions. In our study, banded cricket (BC) and mealworm larvae (ML) were analyzed. The proximate composition was determined according to Association of Official Analytical Chemists. The mineral content was determined by colorimetry and mass spectrometry. Fatty acid methyl esters (FAMEs) were obtained from the samples and separated using a gas chromatography apparatus, coupled with a mass spectrometer. Our research confirmed that insects are a rich source of protein, with ML containing significantly more protein than BC (74.41 and 65.66 g/100 g dry matter (DM), respectively). In terms of the content of macrominerals, ML was significantly richer than BC, especially in terms of magnesium content (8.75 g/100 g DM). In terms of the content of saturated fatty acids, BC contained almost twice as much as ML (40.05 and 24.74% of the sum of fatty acids, respectively). EPA and DHA were only detected in the fat of BC. The presented results prove that both ML and BC can be good sources of protein both in human and companion animal diets. The component that is predominantly high in insects is fat, with a favorable fatty acid profile, especially in terms of polyunsaturated fatty acids. This study contributes new knowledge on the nutritional value of edible insects. In this research, we included three different nitrogen conversion factors for crude protein content. Our results partially confirm previous studies by other authors, although they provide new information on the content of fatty acids.

Fatty Acid and Amino Acid Profiles of Seven Edible Insects: Focus on Lipid Class Composition and Protein Conversion Factors

This study is based on the fatty acid and amino acid profiles of seven edible insect species: Acheta domesticus, Alphitobius diaperinus, Blaptica dubia, Galleria mellonella, Locusta migratoria, Tenebrio molitor, and Zophobas morio. The aim of the present study is to provide new data on the fatty acid distributions among lipid classes as well as the species-specific protein conversion factor (Kp) of a wide range of insects in order to further improve the nutritional characterisation of insects as food. Oleic acid was the predominant fatty acid in all insects except for A. domesticus, in which a significantly higher percentage of linoleic acid was found. The majority of the lipids were neutral lipids. A significant amount of α-linolenic acid in the phospholipid fraction of L. migratoria was shown, while in T. molitor, phospholipids were the only fraction in which a measurable amount of docosahexaenoic acid was found. Overall, in most insects, the phospholipid fraction had the highest polyunsaturated fatty acid content compared to the other classes, which may be protective in terms of auto-oxidative stability. Kp values in the range of 4.17 to 6.43 were obtained. Within the nutritional quality indices, all insects showed healthy fatty acids and high-quality amino acid profiles.

Exploring the Potential of Sago Caterpillars as Cooking Oils: Extraction, Purifying and Characterization

<b>Background and Objective:</b> The dual demand for palm oil, both as a cooking oil and as a raw material for biodiesel, gives rise to concerns regarding potential shortages. Hence, it is crucial to explore alternative sources of cooking oil, with one such alternative being the oil extracted from sago caterpillars. This study aims to extract and determine the characteristics of sago caterpillar oil and its potential as cooking oil. <b>Materials and Methods:</b> Sago caterpillar oil extraction was done using pressing, Soxhlet extraction and Folch's lipid extraction. The yield of sago caterpillar oil obtained by pressing, Soxhlet and Folch's lipid extraction were 20, 16 and 2.2%, respectively. Oil purifying was done using degumming, neutralization and bleaching. Furthermore, the resulting sago caterpillar oil was characterized physically, chemically and organoleptic. <b>Results:</b> The sago caterpillar oil met the requirements as cooking oil based on the Indonesian National Standard for cooking oil and other chemical parameters. The results of the analysis of sago caterpillar oil with gas chromatography-mass spectrometer showed that the sago caterpillar oil contained 0.15% lauric acid, 2.06% myristic acid, 5.92% palmitoleic acid, 55.05% palmitic acid, 0.84% linoleic acid, 34.00% oleic acid and 1.43% stearic acid. The main peak positions from the fourier transform infrared spectrophotometer are at 725, 1118, 1165, 1234, 1373, 1458, 1743, 2854 and 2924 cm¹. The results of the analysis of sago caterpillar oil showed that the lipid profile of sago caterpillar oil was similar to commercial palm oil. <b>Conclusion:</b> Based on the results of extraction, purifying and characterization, it was concluded that sago caterpillar oil has the potential to be used as cooking oil.

Evaluating an emerging technology-based biorefinery for edible house crickets

Introduction

Edible insects, specifically house crickets, are expected to play an important role in the future food systems due to their rich nutritional profile, low environmental impact and growing consumer acceptance as food. Their content of proteins, lipids, chitin and phenolics offer great potential for the valorization of their biomass into nutritional end products and fractions. Furthermore, emerging food processing technologies and green solvents are relevant for improving the valorization process.

Materials and methods

High pressure (HP) and ultrasound (US) processing were implemented in an insect biorefinery system, where a hexane/methanol/water solvent was used to separate fat, phenolics and a solid fraction containing proteins and chitin. Subsequently, a deep eutectic solvent of betaine and urea (B/U) was used to for protein and chitin isolation.

Results

A maximum of 15% of fat was isolated, with no positive effect from the US or HP treatments. The US treatment enhanced the phenolic extraction yield by 38.69%, while HP negatively affected the antioxidant capacity. B/U was efficient in separating proteins and chitin, resulting in a protein concentrate with a protein content ≥80% and a chitinous fraction with a chitin content ≥70%.

Conclusion

House cricket biomass can be refined into valuable fractions with a quick and simple method, making the process industrially relevant.

Edible insects and legumes exert an antioxidant effect on human colon mucosal cells stressed with 2,2'-azobis (2-amidinopropane)-dihydrochloride

Introduction

Edible insects have been recognized as a more sustainable source of nutrients and bio-active compounds than animal-based products, in line with classical vegetable sources such as legumes. In this study, we assessed the antioxidant properties of four edible insects (silkworms, grasshoppers, mealworms and giant worms) and four legume seeds (lentils, chickpeas, Roveja peas and grass peas).

Methods

After the aqueous extraction or in vitro simulated digestion process, selected products were assessed for: (i) in vitro antioxidant capacity through Ferric Reducing Antioxidant Power (FRAP) assay; (ii) the ability to reduce free radicals production induced by a pro-oxidant agent in cells of human colonic mucosa.

Results

All the aqueous extracts and digesta of edible insects displayed significantly higher in vitro antioxidant activity than legumes. Moreover, edible insects at all tested concentrations were able to exert an antioxidant effect in the cellular model, while legumes were effective mainly at high concentrations.

Discussion

Despite human trials are need to confirm and define these results in a physiological situation, here we suggest a role for edible insects in oxidative stress prevention. Since oxidative stress is strongly correlated with several intestinal pathologies, the results obtained could be interesting for the prevention and relief of the negative symptoms, offering new advantages to their already known ecological and nutritional properties.

Lesser mealworm (Alphitobius diaperinus L.) larvae oils extracted by pure and binary mixed organic solvents: Physicochemical and antioxidant properties, fatty acid composition, and lipid quality indices

Insect oil is one of the most sustainable lipid sources with remarkable health effects. Herein, the type of organic solvents (i.e., n-hexane, ethanol, and isopropanol) and their binary mixtures was evaluated based on the quantity (e.g., yield extraction) and quality (e.g., bioactive compounds, thermal stability, DPPH scavenging rate, fatty acid profile, and nutritional indices) of lesser mealworm oils. The oils extracted by ethanol/isopropanol and ethanol/n-hexane significantly showed the highest extraction yield and efficiency, lightness, accelerated thermal stability, phenolics, tocopherols, vitamin D, campesterol, β-sitosterol, phosphatidylinositol and phosphatic acid, linoleic acid, and hypocholesterolemic/hypercholesterolemic ratio, while these organic mixtures meaningfully extracted lipids with the lowest peroxide value, free fatty acid, and atherogenicity and thrombogenicity indices. These solvents compared to pure ones could dissolve membrane and internal lipids with the complete disintegration of external structures. The ethanol/isopropanol mixture would be a promising solvent for n-hexane substitution to extract this oil on an industrial scale.

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.

Analysis of the Composition of Different Instars of Tenebrio molitor Larvae using Near-Infrared Reflectance Spectroscopy for Prediction of Amino and Fatty Acid Content

Insects are a sustainable protein source for food and feed. The yellow mealworm (Tenebrio molitor L.) is a promising candidate for industrial insect rearing and was the focus of this study. This research revealed the diversity of Tenebrio molitor larvae in the varying larval instars in terms of the nutritional content. We hypothesized that water and protein are highest in the earlier instar, while fat content is very low but increases with larval development. Consequently, an earlier instar would be a good choice for harvest, since proteins and amino acids content decrease with larval development. Near-infrared reflectance spectroscopy (NIRS) was represented in this research as a tool for predicting the amino and fatty acid composition of mealworm larvae. Samples were scanned with a near-infrared spectrometer using wavelengths from 1100 to 2100 nm. The calibration for the prediction was developed with modified partial least squares (PLS) as the regression method. The coefficient for determining calibration (R²_C) and prediction (R²_P) were >0.82 and >0.86, with RPD values of >2.20 for 10 amino acids, resulting in a high prediction accuracy. The PLS models for glutamic acid, leucine, lysine and valine have to be improved. The prediction of six fatty acids was also possible with the coefficient of the determination of calibration (R²_C) and prediction (R²_P) > 0.77 and >0.66 with RPD values > 1.73. Only the prediction accuracy of palmitic acid was very weak, which was probably due to the narrow variation range. NIRS could help insect producers to analyze the nutritional composition of Tenebrio molitor larvae fast and easily in order to improve the larval feeding and composition for industrial mass rearing.

Consumers' acceptance toward whole and processed mealworms: A cross-country study in Belgium, China, Italy, Mexico, and the US

The interest in edible insects as food is growing, both in traditional and non-traditional insect-eating countries given their advantages in terms of sustainability and nutritional content. However, only a few studies have conducted cross-country investigations on the acceptance of including processed or whole insects in the diet. Thus, this study aimed to examine to which extent consumers were accepting (i) whole and visible mealworms, (ii) processed mealworms in their diet and (iii) to explore the factors affecting the acceptance level of consuming mealworms in countries with and without entomophagy tradition. An online survey was applied to collect responses (3,006) from five countries-i.e., Belgium, China, Italy, Mexico, and the US-using a quota sampling method. Moreover, an information treatment was included with about half of the participants receiving information about the advantages of edible insects as food (ingredient) and the presence of food safety regulations. Across countries, gender was the main factor affecting acceptance level as men accepted mealworms more than women. Entomophagy tradition mainly explained the differences among countries. Countries with entomophagy traditions (Mexico and China) showed higher acceptance of including whole or processed mealworms in the diet compared to countries with no entomophagy traditions (i.e., Belgium, Italy, and the US). While information and age did affect differently the acceptance of including processed mealworms in countries with entomophagy traditions showing that consumer acceptance was affected by information in Mexico and by age in China. Whereas it was found that younger people (below 42 years old) in countries without entomophagy tradition were more open to accepting processed mealworms in their diet. Moreover, across countries, the acceptance of including processed mealworms was higher compared to whole mealworms. These findings provide insights into which consumer segments to target and the potential impact of information when introducing new insect-based foods in countries with and without entomophagy traditions.

Overcoming obstacles in insect utilization

Edible insects have long been part of human diets in some countries, and they are expected to become an important alternative food source because of their nutritional value and favorable environmental impact. However, insects’ consumption safety and consumer acceptance are still significant barriers to market positioning, mainly in Western regions. Therefore, several processing technologies have been applied to develop insect-based food products and derivatives to increase consumer safety, shelf-life, and sensorial properties, including appearance. The processing pathway for insects as food might then be focused on eliminating such concerns. However, even though there is enough information related to processing techniques for edible insects, the use of the treated material has been limited as a substitute rather than a main constituted nutritional component. Moreover, there is little information about novel technologies and uses of insect derivatives compared to the minimally processed insect, as in the case of flours. This review presents the food safety (biological and chemical hazards) and cultural aspects of difficulties of eating insects and the role of processing raw material, extraction of insect derivatives (lipids and proteins), and food prototypes development on safety and consumer acceptance.

Graphical abstract

Nutritional Composition, Phenolic Compounds and Antioxidant Activity of Different Samples of Water Boatmen Eggs (Hemiptera: Corixidae)

The group of aquatic insects collectively called "water boatmen" or "Axayacatl" (Hemiptera: Corixidae) and their eggs, called "Ahuahutle", have been consumed and cultivated since the pre-Hispanic era in Mexico. Nevertheless, food composition databases contain limited information on the nutritional composition of these eggs. This work evaluates the macronutrients and bioactive compounds of water boatmen eggs obtained from three different locations in Mexico. The primary analyses to be determined for the first time were some bioactive compounds in the eggs, such as phenolic compounds, total flavonoids, condensed tannins content, antioxidant activity (DPPH and ABTS), and, additionally, fatty acids and proximal composition. The results showed that the sample from Hidalgo (AMC) presented the highest number of phenolic compounds (855.12 ± 0.52), followed by ALT (125.52 ± 0.05) and, with the lowest amount, AMT (99.92 ± 0.13), all expressed in an mg GAE/g sample. ALT indicated the highest mol TE/g sample concentration for ABTS (25.34 ± 0.472) and DPPH (39.76 ± 0.054), showing a significant difference in the DPPH method with the AMT samples. The three Corixidae egg samples had between 15 to 18 different fatty acid profiles, and there were statistically significant differences (Student's t-test ≤ 0.05) between the means using MSD. The total fats of the three samples were between 12.5 and 15.5 g/100 g dry basis. In addition, Corixidae eggs are excellent protein sources. Thus, water boatmen's eggs can be considered to be a food rich in bioactive compounds.

Frying dough with yellow mealworm oil: Aroma profile and consumer perception at a central location test and at home

Insect oil is a valuable fraction that is obtained from insect processing. The aim of this study is to evaluate the impact of yellow mealworm oil (YMW) oil (crude, deodorized, and blended with vegetable oil) on the sensory evaluation and aroma profile of fried dough. The sensory evaluation was performed in a sensory lab (central location test, CLT) and at home in order to examine how the evaluation environment or context impacts consumer perceptions. The strongest liking and preference were found for the donuts that were fried in 100% deodorized YMW oil and in YMW oil blended with vegetable oil. The evaluation environment did not affect overall liking scores but had an impact on sensory profiling, with more discriminating sensory terms observed for the test that was conducted at the sensory lab than for the test that was conducted at home. A distinctive profile of volatile organic compounds (VOCs) was found for every fried dough. The discrimination between VOCs and other frying oils that were observed is well in line with the sensory descriptors and the consumer test results. Acetic acid, acetic acid ethenyl ester, and tetrahydro-6-propyl-2H-Pyran-2-one were present in the doughs that were fried in crude YMW oil and in its blend with vegetable oil. They were absent from deodorized YMW oil and from its blend with vegetable oil. This study shows that, as far as fried donuts are concerned, deodorized YMW oil is an alternative to a vegetable oil-the two lead to similar sensorial experiences and preferences. PRACTICAL APPLICATION: Yellow mealworm oil (YMW) oil is a co-product of insect protein that can be valorized in the food industry. In the present study, it is demonstrated that the deodorization of YMW oil produces positive sensorial experiences and increases consumer acceptance of insect-based food. Furthermore, findings indicate that consumer testing at home yields similar acceptance and preference ratings suggesting that this type of testing may be an alternative means of collecting reliable consumer data.

Nutritional Composition, Health Benefits, and Application Value of Edible Insects: A Review

For thousands of years, edible insects have been used as food to alleviate hunger and improve malnutrition. Some insects have also been used as medicines because of their therapeutic properties. This is not only due to the high nutritional value of edible insects, but more importantly, the active substances from edible insects have a variety of biofunctional activities. In this paper, we described and summarized the nutritional composition of edible insects and discussed the biological functions of edible insects and their potential benefits for human health. A summary analysis of the findings for each active function confirms that edible insects have the potential to develop functional foods and medicines that are beneficial to humans. In addition, we analyzed the issues that need to be considered in the application of edible insects and the current status of edible insects in food and pharmaceutical applications. We concluded with a discussion of regulations related to edible insects and an outlook on future research and applications of edible insects. By analyzing the current state of research on edible insects, we aim to raise awareness of the use of edible insects to improve human health and thus promote their better use and development.

Ultrasound-Assisted Alcoholic Extraction of Lesser Mealworm Larvae Oil: Process Optimization, Physicochemical Characteristics, and Energy Consumption

The ultrasound-assisted extraction (UAE) of oil from lesser mealworm (Alphitobius diaperinus L.) larvae powders (LMLPs) using ethanol/isopropanol as the superior solvent was optimized. The evaluation of time (9.89−35.11 min), solvent-to-LMLPs (2.39−27.61 v/w), and temperature (16.36−83.64 °C) showed that the highest extraction efficiency (EE, 88.08%) and in vitro antioxidant activity (IVAA) of reducing power (0.651), and DPPH free-radical scavenging capacity (70.79%) were achieved at 22.5 v/w solvent-to-LMLPs and 70 °C for 22.64 min. Optimal ultrasound conditions significantly improved the EE than n-hexane extraction (60.09%) by reducing the electric energy consumption by ~18.5 times from 0.637 to 0.035 kWh/g. The oil diffusivity in ethanol-isopropanol during the UAE (0.97 × 10−9 m2/s) was much better than that of n-hexane (5.07 × 10−11 m2/s). The microstructural images confirmed the high efficiency of ethanol-isopropanol in the presence of ultrasounds to remove oil flakes from the internal and external surfaces of LMLPs. The improved IVAA was significantly associated with the total phenolic (4.306 mg GAE/g, r = 0.991) and carotenoid (0.778 mg/g, r = 0.937) contents (p < 0.01). Although there was no significant difference in the fatty acid profile between the two extracted oils, ethanol-isopropanol under sonication acceptably improved oxidative stability with lower peroxides, conjugated dienes and trienes, and free fatty acids.

The Characteristic of Insect Oil for a Potential Component of Oleogel and Its Application as a Solid Fat Replacer in Cookies

The larvae of Tenebrio molitor, an edible insect, have recently attracted attention in the food industry as a protein supplement or future food material. However, despite more than 30% of the total weight being fat content, few studies have been conducted on the fat (oil) derived from Tenebrio molitor larvae (TM oil) and its food utilization. In this study, TM oil was extracted and its fatty acid composition and antioxidant activity were investigated. Then, the oleogels were prepared with TM oil and oleogelators (candelilla wax, carnauba wax, and beeswax) and their rheological and thermal properties were evaluated to elucidate their utilization as a solid fat replacer in cookies. In the results, TM oil contained 73.6% unsaturated fatty acids and showed a lower antioxidant activity than olive oil. Although the highest hardness was shown in oleogel with candelilla wax, the highest viscoelasticity above 50 °C was observed for oleogel with carnauba wax. The highest melting point was observed in carnauba oleogel. Lower peroxide values were observed in the oleogel samples than for TM oil, indicating that oleogelation of structuring oil improved the oxidative stability of TM oil. In addition, the shortening replacement with carnauba wax oleogel showed a desirable cookie quality in terms of spreadability and texture properties.

Functional, Antioxidant, and Anti-Inflammatory Properties of Cricket Protein Concentrate (Gryllus assimilis)

Edible insects can represent an alternative to obtain high-quality proteins with positive biological properties for human consumption. Cricket flour (Gryllus assimilis) was used to obtain cricket protein concentrate (CPC) using pHs (10.0 and 12.0) of extraction and pHs (3.0, 4.0, 5.0, and 6.0) of isoelectric precipitation (pI). Protein content, water and oil absorption capacity, protein solubility, antioxidant, and anti-inflammatory activities were determined. In addition, the protein profile was characterized by electrophoresis and the in vitro CPC digestibility was evaluated. Cricket flour presented 45.75% of protein content and CPC 12-5.0 presented a value of 71.16% protein content using the Dumas method. All samples were more soluble at pH 9.0 and 12.0. CPC 12-3.0 presented a percentage of water-binding capacity (WBC) of 41.25%. CPC 12-6.0 presented a percentage of oil-binding capacity (OBC) of 72.93%. All samples presented a high antioxidant and anti-inflammatory activity. CPC 12-4.0 presented a value FRAP of 70,034 umol trolox equivalents (TE)/g CPC, CPC 12-6.0 presented a value ABTS of 124,300 umol TE/g CPC and CPC 10-3.0 presented a DPPH value of 68,009 umol TE/g CPC. CPC 10-6.0 and CPC 12-6.0 presented high anti-inflammatory activity, with values of 93.55% and 93.15% of protection, respectively. CPCs can be used as functional ingredients in the food industry for their excellent functional and biological properties.

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.

Bacterial Outer Membrane Permeability Increase Underlies the Bactericidal Effect of Fatty Acids From Hermetia illucens (Black Soldier Fly) Larvae Fat Against Hypermucoviscous Isolates of Klebsiella pneumoniae

Behind expensive treatments, Klebsiella pneumoniae infections account for extended hospitalization’s high mortality rates. This study aimed to evaluate the activity and mechanism of the antimicrobial action of a fatty acid-containing extract (AWME3) isolated from Hermetia illucens (HI) larvae fat against K. pneumoniae subsp. pneumoniae standard NDM-1 carbapenemase-producing ATCC BAA-2473 strain, along with a wild-type hypermucoviscous clinical isolate, strain K. pneumoniae subsp. pneumoniae KPi1627, and an environmental isolate, strain K. pneumoniae subsp. pneumoniae KPM9. We classified these strains as extensive multidrug-resistant (XDR) or multiple antibiotic-resistant (MDR) demonstrated by a susceptibility assay against 14 antibiotics belonging to ten classes of antibiotics. Antibacterial properties of fatty acids extracted from the HI larvae fat were evaluated using disk diffusion method, microdilution, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), half of the inhibitory concentration (MIC50), and bactericidal assays. In addition, the cytotoxocity of AWME3 was tested on human HEK293 cells, and AWME3 lipid profile was determined by gas chromatography-mass spectrometry (GC-MS) analysis. For the first time, we demonstrated that the inhibition zone diameter (IZD) of fatty acid-containing extract (AWME3) of the HI larvae fat tested at 20 mg/ml was 16.52 ± 0.74 and 14.23 ± 0.35 mm against colistin-resistant KPi1627 and KPM9, respectively. It was 19.72 ± 0.51 mm against the colistin-susceptible K. pneumoniae ATCC BAA-2473 strain. The MIC and MBC were 250 μg/ml for all the tested bacteria strains, indicating the bactericidal effect of AWME3. The MIC50 values were 155.6 ± 0.009 and 160.1 ± 0.008 μg/ml against the KPi1627 and KPM9 isolates, respectively, and 149.5 ± 0.013 μg/ml against the ATCC BAA-2473 strain in the micro-dilution assay. For the first time, we demonstrated that AWME3 dose-dependently increased bacterial cell membrane permeability as determined by the relative electric conductivity (REC) of the K. pneumoniae ATCC BAA-2473 suspension, and that none of the strains did not build up resistance to extended AWME3 treatment using the antibiotic resistance assay. Cytotoxicity assay showed that AWME3 is safe for human HEK293 cells at IC₅₀ 266.1 μg/ml, while bactericidal for all the strains of bacteria at the same concentration. Free fatty acids (FFAs) and their derivatives were the significant substances among 33 compounds identified by the GC-MS analysis of AWME3. Cis-oleic and palmitoleic acids represent the most abundant unsaturated FAs (UFAs), while palmitic, lauric, stearic, and myristic acids were the most abundant saturated FAs (SFAs) of the AWME3 content. Bactericidal resistant-free AWM3 mechanism of action provides a rationale interpretations and the utility of HI larvae fat to develop natural biocidal resistance-free formulations that might be promising therapeutic against Gram-negative MDR bacteria causing nosocomial infections.

Characterization of lipid extracts from the Hermetia illucens larvae and their bioactivities for potential use as pharmaceutical and cosmetic ingredients

There is an increasingly growing demand for the use of natural and sustainable bioactives in the field of the pharmaceutical and cosmetic industries. The biomass from black soldier fly larvae (Hermetia illucens) can be viewed as an innovative source of compounds with high aggregate value and marketing potential due to the sustainable organic matter bioconversion process used as substrate for its development. This insect can be a source of lipid compounds with high added value, mainly due to its high content in fatty acids (FA) with potential applicability in the pharmaceutical and cosmetic industry. In this context, in this work different extraction methods were tested (decoction, microwaves, maceration and ultrasound), using water, acetone, n-hexane as extraction solvents, to evaluate yields of the BSF larvae lipid extracts, as well as their lipid profile, and a preliminary safety screening was conducted. Results show that despite using different extraction techniques and solvents, similar FA composition profiles were obtained. The lauric acid content (C12: 0) is elevated in all the extracts in relation to the other FA, ranging 37%-62%. The contents in palmitic (C16: 0) and oleic (C18: 1n-9) acids, were also high in all applied extraction methods. The omega-6 FA (ω-6 PUFAs), mainly linoleic acid (C18: 2n6c), were also identified in the lipid fraction of BSF larvae biomass, with a content variation between 4.5% and 17.7%, while the omega-3 group, namely α-Linolenic acid (C18: 3n3), presented values between 0.66% and 1.95%. None of the extracts presented toxicity in preliminary tests with the Artemia salina model. Through this study, it was possible to confirm that BSF larvae oil can be obtained by sustainable methods, containing a broad mixture of FA and being highly rich in lauric acid, with a promising skin care applicability.

Analysis of wheat flour-insect powder mixtures based on their near infrared spectra

Insects are gaining more and more space in food and feed sectors, creating an intense scientific interest towards insects as food ingredients. Several papers deal with cereal-based products complemented by insect powder in the past few years. However, adulteration and quality control of such products present some hot topics for researchers, e.g., how can we justify the amounts and/or species of the insects used in the given products? Our paper aims to answer such questions by analysing seven edible insect powders of different species independently. The mixtures with wheat flour were analysed using near infrared spectroscopy and chemometric methods. Not only powders of different species were clearly differentiated, but also mixtures created by different amounts of wheat flour. Prediction of insect content showed 0.65% cross-validated error. The proposed methodology gives an excellent tool for quality control of insect-based cereal food products.

Lipids from Insects in Cosmetics and for Personal Care Products

Simple Summary

The use of insects as a new source of lipids is a topic of great interest from both environmental and economic points of view. In addition to use in feed and energy applications, lipids could be used for the formulation of personal care products. The cosmetics industry is always in search of new ingredients to use in novel product formulations. The processes mediated by bioconverter insects, such as Hermetia illucens, are really advantageous because starting from substrates of low economic and biological value (agri-food by-products, zootechnical, catering, and other waste), it is possible to obtain products of high commercial value. The composition of insect lipids depends on the feeding substrate, as well as the insect species, therefore for each personal care application, it is possible to find the most suitable starting conditions. In this review, we display a general outlook on insect lipids, the extraction processes, and their use in cosmetics and personal care fields.

Abstract

Insects, the most varied group of known organisms on Earth, are arousing great interest also for the possibility to use them as a feed and food source. The mass rearing of some species, defined as “bioconverters”, is spreading worldwide, thanks to their sustainability. At the end of the bioconversion process, breeders obtain eco-friendly biomolecules of high biological and economic value, including proteins and lipids, from larvae of bioconverter insects, in particular Hermetia illucens. Besides the most classical use of insect lipids as food additives, they are also used in the formulation of several products for personal care. The composition of insect lipids depends on the substrate on which the insects are reared but also on the insect species, so the cosmetic producers should consider these features to choose their insect starting point. The most abundant fatty acids detected in H. illucens are lauric, myristic, palmitic, and oleic acids, regardless of feed substrate; its fatty acids composition is favorable for soap composition, while their derivatives are used for detergent and shampoo. Here, we offer an overview of insect lipids, their extraction methods, and their application in cosmetics and personal care products.

Fatty acid profile, minor bioactive constituents and physicochemical properties of insect-based oils: A comprehensive review

Insect-based food or ingredients have received tremendous attention worldwide because of their potential to ensure food and nutrition security, mitigating the reliance on land-dependent agricultural products. Indeed, insect-farming has low environmental impacts with reduced land, water and energy input. More importantly, insects are rich in high quality proteins and fats. They are also excellent sources of minerals, vitamins and bioactive compounds. Insect-based lipids are intriguing because they may contain high levels of unsaturated fatty acids particularly linoleic and α-linolenic acids. Besides, the insect-based lipids also show a considerable amount of bioactive components such as tocols, sterols and carotenoids. However, their fatty acid compositions and the nutritional values may vary depending on species, feed composition, developmental stage, geographical locations, and extraction techniques. Therefore, the present article aims to provide a comprehensive review on the fatty acid composition, the minor bioactive constituents and the physicochemical properties of fats and oils derived from insects of different orders (Coleoptera, Lepidoptera, Hymenoptera, Orthoptera, Hemiptera and Diptera). The various parameters affecting the nutritional compositions of the insect-based lipids will also be highlighted. These information will definitely provide a detailed insight on the potential applications of these fats in various food systems based on their unique properties.