Insects for Food and Feed-Safety Aspects Related to Mycotoxins and Metals

Edible insects as functional foods: bioactive compounds, health benefits, safety concerns, allergenicity, and regulatory considerations

The growing demand for sustainable and nutrient-rich food sources has positioned edible insects as a viable alternative to traditional animal-based proteins. This review explores the bioactive properties and food safety considerations of edible insects, emphasizing their potential health benefits and the challenges associated with their widespread consumption. Research has identified bioactive compounds in insects with antioxidant, antimicrobial, immunomodulatory, cardioprotective, and digestive health-promoting properties, highlighting their potential as functional foods for preventing or managing chronic diseases such as cardiovascular conditions and inflammatory disorders. Additionally, this review examines findings related to contaminants in edible insects, including heavy metals, microbial pathogens, and allergens, which could pose health risks. Certain insect species have shown accumulation of heavy metals, such as cadmium and lead, depending on their diet and environment. Moreover, microbial contamination, including bacteria, fungi, and parasites, can occur if farming and processing conditions are not properly controlled. Furthermore, insect proteins exhibit cross-reactivity with allergens found in crustaceans and dust mites, raising concerns for individuals with food allergies. For edible insects to be successfully integrated into global food systems, further technological advancements, regulatory oversight, and consumer acceptance strategies must be implemented. Addressing these challenges will enable edible insects to become a key component of sustainable food systems, contributing to global nutrition, environmental sustainability, and human health.

Arthropods in soil reclamation and bioremediation: Functional roles, mechanisms and future perspective

Soil arthropods are a diverse group of invertebrates that play pivotal roles in nutrient cycling, decomposition, soil structure formation, and regulation of soil biodiversity. Understanding the ecological significance of soil arthropods and their interactions with other soil organisms is crucial. This review paper examines the potential of arthropods in improving soil health and quality, with a specific focus on their relevance in acidic, saline/alkaline, and contaminated soils. The paper investigates the interactions between arthropods and their associated microbiomes, their contributions to soil physical and chemical properties, their influence on nutrient cycling and organic matter mineralization, as well as their role as indicators of soil health due to their sensitivity to environmental changes. Furthermore, the review explores how arthropods enhance the activities of microorganisms, such as bacteria, fungi, and yeast, which employ molecular mechanisms to remediate heavy metal contamination in soils. Lastly, the paper addresses key challenges and future directions for utilizing soil arthropods in the restoration of environmentally friendly soils.

Mycotoxins in Food: Cancer Risks and Strategies for Control

Mycotoxins are toxic compounds produced by fungi such as Aspergillus, Penicillium, and Fusarium, contaminating various food crops and posing severe risks to food safety and human health. This review discusses mycotoxins' origins, significance, and impact, particularly in relation to cancer risk. Major mycotoxins like aflatoxins, ochratoxins, fumonisins, zearalenone, and patulin are examined, along with their sources and affected foods. The carcinogenic mechanisms of these toxins, including their biochemical and molecular interactions, are explored, as well as epidemiological evidence linking mycotoxin exposure to cancer in high-risk populations. The review also highlights critical methodologies for mycotoxin detection, including HPLC, GC-MS, MS, and ELISA, and the sample preparation techniques critical for accurate analysis. Strategies for controlling mycotoxin contamination, both pre- and post-harvest, are discussed, along with regulations from organizations like the FAO and WHO. Current challenges in detection sensitivity, cost, and control effectiveness are noted. Future research is needed to develop innovative analytical techniques, improve control strategies, and address the influence of climate change on mycotoxin production. Finally, global collaboration and emerging technologies are essential for advancing mycotoxin control and enhancing food safety.

Presence of Trace Elements in Edible Insects Commercialized through Online E-Commerce Platform

This study aimed to evaluate the presence of various elements in edible insect-based food products available for human consumption. Several products were analyzed using atomic spectroscopy, and descriptive statistical analysis was conducted with IBM SPSS Statistics 27. The results revealed the presence of elements such as arsenic, cadmium, copper, magnesium, nickel, silver, lead, tungsten, uranium, mercury, platinum, aluminum, beryllium, bismuth, lithium, antimony, and thallium. Significant differences were found based on product type, insect species, and country of origin. The findings underscore the need to assess each insect species for its potential as a food source, taking into account element bioaccumulation factors. A comprehensive, global approach is essential for ensuring the food safety of edible insects as a sustainable protein source. Further research is needed to address these safety concerns.

Evaluation of Risk Factors Associated with Selected Elements in Veterinary Active Pharmaceutical Ingredients Using ICP-MS

One of the major concerns for animal health is the pollution of food and medicines given to animals by non-essential and toxic elements, which also poses a risk to human health via the food chain. The essential (Ca, Cr, Mn, Fe, Co, and Ni) and non-essential elements (Li, Ti, V, Ga, Ag, Cd, In, Ba, Bi, Th, and U) were monitored using inductively coupled plasma mass spectrometry (ICP-MS) in veterinary active pharmaceutical ingredients (V APIs). Samples were divided into four groups including antibiotic (14 samples), anthelmintic (7 samples), anticoccidial (5 samples), and externally used (5 samples). The results of the antibiotic group had the highest concentrations of most elements. The concentrations of the targeted elements were below the permissible limits as recommended by the United States Pharmacopeia (USP). The target hazard quotient (THQ) and the total target hazard quotient (TTHQ) were applied to evaluate the animal health risk associated with the exposure of the target elements in V API samples; the results showed that elements do not pose any risk to animals in all samples as indicated by THQ values less than 1. Validation parameters performed in this study showed good accuracy and validity of the ICP-MS analysis method, with good linearity (R2 ˃ 0.990), and the relative standard deviations (%RSD) were < 4% for all target elements. Analysis of variance (ANOVA-one way) was used to compare the means of veterinary drug groups for all targeted elements. The results showed that all elements have p-values < 0.05 except 52Cr and 54Fe.

Mitigation Strategies against Food Safety Contaminant Transmission from Black Soldier Fly Larva Bioconversion

The black soldier fly larva, Hermetia illucens, can efficiently convert organic waste into biomatter for use in animal feed. This circularity comes with a risk of contaminating downstream consumers of the larval products with microbes, heavy metals, and other hazards potentially present in the initial substrate. This review examines research on mitigation techniques to manage these contaminants, from pretreatment of the substrate to post-treatment of the larvae. While much research has been done on such techniques, little of it focused on their effects on food safety contaminants. Cheap and low-technology heat treatment can reduce substrate and larval microbial load. Emptying the larval gut through starvation is understudied but promising. Black soldier fly larvae accumulate certain heavy metals like cadmium, and their ability to process certain hazards is unknown, which is why some government authorities are erring on the side of caution regarding how larval bioconversion can be used within feed production. Different substrates have different risks and some mitigation strategies may affect larval rearing performance and the final products negatively, so different producers will need to choose the right strategy for their system to balance cost-effectiveness with sustainability and safety.

The first full study of heavy metal(loid)s in western-European hedgehogs (Erinaceus europaeus) from Portugal

The western-European hedgehog (Erinaceus europaeus) is an insectivore with a wide distribution in Portugal and a potential tool for biomonitoring relevant One Health hazards, including heavy metal(loid)s' pollution. The aim of this study was to positively contribute to the current knowledge about the metal(loid) pollution in Portugal. Forty-six hedgehogs (from rescue centres; with known provenance) were necropsied. Sex, age category and weight were determined. Spines, liver and kidney were collected, and metalloid concentrations were determined by inductively coupled plasma mass spectrophotometry (ICP-MS). In general, results did not present alarming metal(loid) concentrations, with the exception of cadmium (Cd) (in the kidneys) and copper (Cu). Hedgehogs from Viana do Castelo and Viseu showed elevated concentrations of arsenic (As) and Castelo Branco presented concerning values of cadmium (Cd). Adult and heavier hedgehogs tended to present higher levels of metal(loid)s. Sex does not seem to significantly affect the metal(loid)s' concentrations. Further analysis would be needed to prioritize areas with detail and allow the application of the necessary mitigation strategies.

Improving the nutritional values of yellow mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) larvae as an animal feed ingredient: a review

Yellow mealworm larvae (YML; Tenebrio molitor) are considered as a valuable insect species for animal feed due to their high nutritional values and ability to grow under different substrates and rearing conditions. Advances in the understanding of entomophagy and animal nutrition over the past decades have propelled research areas toward testing multiple aspects of YML to exploit them better as animal feed sources. This review aims to summarize various approaches that could be exploited to maximize the nutritional values of YML as an animal feed ingredient. In addition, YML has the potential to be used as an antimicrobial or bioactive agent to improve animal health and immune function in production animals. The dynamics of the nutritional profile of YML can be influenced by multiple factors and should be taken into account when attempting to optimize the nutrient contents of YML as an animal feed ingredient. Specifically, the use of novel land-based and aquatic feeding resources, probiotics, and the exploitation of larval gut microbiomes as novel strategies can assist to maximize the nutritional potential of YML. Selection of relevant feed supplies, optimization of ambient conditions, the introduction of novel genetic selection procedures, and implementation of effective post-harvest processing may be required in the future to commercialize mealworm production. Furthermore, the use of appropriate agricultural practices and technological improvements within the mealworm production sector should be aimed at achieving both economic and environmental sustainability. The issues highlighted in this review could pave the way for future approaches to improve the nutritional value of YML.

Adoption of on-farm feed safety practices among livestock farmers: Evidence from Saudi Arabia

Compliance with feed safety standards and practices on the farm promotes sustainable livestock production and can positively affect the environment and human health. This study aims to examine farmers' on-farm adoption of feed safety practices and determine the differences in adoption according to the socio-economic characteristics of farmers. An online survey was conducted to collect the study data. The study participants consisted of 442 livestock farmers in Riyadh region, Saudi Arabia. The study findings revealed that farmers highly adopted categories of feed purchasing (77.9 %) and feed mixing and distribution (75.05 %), whereas they were considered as a moderate level adoption regarding feed storing (70.9 %). The cluster analysis results showed two main patterns of adoption- "high adopters" and "moderate adopters"-based on the average level of adoption for 25 feed safety practices examined. The cluster of "high adopters" accounted for 59.9 % of the sample and had higher average adoption in all practices examined. The findings revealed that there are significant differences between the two segments of farmers, corresponding to gender, membership in livestock association, extension contact, raising sheep, and feeding system. This study proposes the regular monitoring of farms to ensure strict adherence to feed safety regulations, with the implementation of awareness and capacity development initiatives pertaining to feed safety concerns.

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.

Insects as an alternative protein source for poultry nutrition: a review

This review summarizes the most relevant scientific literature related to the use of insects as alternative protein sources in poultry diets. The black soldier fly, the housefly, the beetle, mealworms, silkworms, earthworms, crickets, and grasshoppers are in the spotlight because they have been identified as an important future source of sustainable animal proteins for poultry feeding. Insect meals meet poultry requirements in terms of nutritional value, essential amino acid composition, nutrient digestibility, and feed acceptance. Furthermore, they are enriched with antimicrobial peptides and bioactive molecules that can improve global health. Results from poultry studies suggest equivalent or enhanced growth performances and quality of end-products as compared to fish meal and soybean meal. To outline this body of knowledge, this article states established threads of research about the nutrient profiles and the digestibility of insect meals, their subsequent effects on the growth and laying performances of poultry as well as the quality of meat, carcass, and eggs. To fully exploit insect-derived products, the effects of insect bioactive molecules (antimicrobial peptides, fatty acids, and polysaccharides) were addressed. Furthermore, as edible insects are likely to take a meaningful position in the feed and food chain, the safety of their derived products needs to be ensured. Some insights into the current knowledge on the prevalence of pathogens and contaminants in edible insects were highlighted. Finally, the effect of insect farming and processing treatment on the nutritive value of insect larvae was discussed. Our overview reveals that using insects can potentially solve problems related to reliance on other food sources, without altering the growth performances and the quality of meat and eggs.

Biotransfer of heavy metals along the soil-plant-edible insect-human food chain in Africa

Although mining is Zambia's major economic activity, it is implicated in environmental contamination, particularly with heavy metals. This study investigated the accumulation and transfer of heavy metals along the soil-plant-edible insect-human food chain. Our results revealed the presence of eight heavy metals (Arsenic, Cadmium, Chromium, Copper, Iron, Nickel, Lead, and Zinc) with a 28-60 % increase in soil concentrations at the proximity of the mining facilities. There was a higher accumulation of Cd, Cu, Ni, Fe, Pb, and Zn than As and Cr in plant species near the mine. Among the insect species studied, C. forda accumulated nickel significantly higher (70-81 %), I. obscura had higher cadmium (2-84 %) and lead (10-79 %), while I. rubra and M. falciger accumulated higher iron (41-96 %) and zinc (1-67 %), respectively, than other insect species. The quantity of I. obscura consumed (248 g person-1 day-1) was significantly higher (9-37 %) than other insect species. It was noted that the consumption of insects increased the daily intake of heavy metals, enhanced the target hazard quotient, and increased the associated health risks by up to 9 folds compared to the WHO permissible limits meaning that the daily intake of metals consumed depends on the daily quantity of insects consumed. Our findings suggest that the accumulation of heavy metals along the soil-plant-edible insect-human food chain could pose severe human and environmental health risks along the mining gradients. The potential consequences of heavy metal mobility in the consumer trophic levels and the ecotoxicological consequences are particularly concerning. Furthermore, physiological and biological studies are needed to investigate the abovementioned effects.

Effects of undesired substances and their bioaccumulation on the black soldier fly larvae, Hermetia illucens (Diptera: Stratiomyidae)-a literature review

Black soldier fly (BSF), Hermetia illucens (L.) (Diptera: Stratiomyidae), is predominantly reared on organic wastes and other unused complementary substrates. However, BSF may have a buildup of undesired substances in their body. The contamination of undesired substance, e.g., heavy metals, mycotoxins, and pesticides, in BSF mainly occurred during the feeding process in the larval stage. Yet, the pattern of accumulated contaminants in the bodies of BSF larvae (BSFL) is varied distinctively depending on the diets as well as the contaminant types and concentrations. Heavy metals, including cadmium, copper, arsenic, and lead, were reported to have accumulated in BSFL. In most cases, the cadmium, arsenic, and lead concentration in BSFL exceeded the recommended standard for heavy metals occurring in feed and food. Following the results concerning the accumulation of the undesired substance in BSFL's body, they did not affect the biological parameters of BSFL, unless the amounts of heavy metals in their diets are highly exceeding their thresholds. Meanwhile, a study on the fate of pesticides and mycotoxins in BSFL indicates that no bioaccumulation was detected for any of the target substances. In addition, dioxins, PCBs, PAHs, and pharmaceuticals did not accumulate in BSFL in the few existing studies. However, future studies are needed to assess the long-term effects of the aforementioned undesired substances on the demographic traits of BSF and to develop appropriate waste management technology. Since the end products of BSFL that are contaminated pose a threat to both human and animal health, their nutrition and production process must be well managed to create end products with a low contamination level to achieve a closed food cycle of BSF as animal feed.

The accumulation of heavy metals in feeder insects and their impact on animal production

Insects have emerged as a novel feed protein source that could help to produce enough food to feed the growing global population. Good-quality protein content, minerals and bioactive compounds are the main reasons for the use of insects in livestock. Nonetheless, insects should be proven to be safe for use before being used as feeder insects for livestock. The accumulation of heavy metals in the feedstuff is becoming a major food safety concern, as this poses a serious problem to animal health and threatens human health through the transmission of toxic substances into the human food chain. It has been shown that feeder insects grown from agricultural waste materials contain chemical contaminants such as pesticides and veterinary drug residues. Current research mostly focuses on the safety evaluation of undesirable substances in edible insects for human consumption, but rarely indicates if these insects are safe to use in livestock feeds, particularly for avian species. Therefore, owing to the potential risks of heavy metal in animal production, heavy metal residues in feeder insects have received scientific attention. Hence, this review article is intended to evaluate and discuss selected heavy metals in insects, comparing them with toxicity limits for feedstuff of animal origin, and their potential risks of exposure. A literature search on metal elements present in insects was conducted using electronic databases. In addition, the citations included in articles were used to find other relevant articles or documents on this topic. Identified published articles were grouped and evaluated according to the insect species, growth stage and substrate from which the insects were grown. It was observed that the accumulation of heavy metals in insects is mainly associated with agricultural waste materials fed to insects. Furthermore, metal toxicity in animals varies according to animal species and age, metal type, concentration, and chemical form.

Foodborne Diseases in the Edible Insect Industry in Europe-New Challenges and Old Problems

Insects play a key role in European agroecosystems. Insects provide important ecosystem services and make a significant contribution to the food chain, sustainable agriculture, the farm-to-fork (F2F) strategy, and the European Green Deal. Edible insects are regarded as a sustainable alternative to livestock, but their microbiological safety for consumers has not yet been fully clarified. The aim of this article is to describe the role of edible insects in the F2F approach, to discuss the latest veterinary guidelines concerning consumption of insect-based foods, and to analyze the biological, chemical, and physical hazards associated with edible insect farming and processing. Five groups of biological risk factors, ten groups of chemical risk factors, and thirteen groups of physical risks factors have been identified and divided into sub-groups. The presented risk maps can facilitate identification of potential threats, such as foodborne pathogens in various insect species and insect-based foods. Ensuring safety of insect-based foods, including effective control of foodborne diseases, will be a significant milestone on the path to maintaining a sustainable food chain in line with the F2F strategy and EU policies. Edible insects constitute a new category of farmed animals and a novel link in the food chain, but their production poses the same problems and challenges that are encountered in conventional livestock rearing and meat production.

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

Does the presence of heavy metal and catechol contaminants in organic waste challenge the physiological performance of the bioconverter Hermetia illucens?

The increased human activities and the worldwide population growth are constantly increasing the production of solid wastes. Over the years, waste management has thus become a prominent issue for several companies and municipalities, and several engineering techniques have been developed over the years in order to convert wastes into other solid materials or fuels. Yet, several techniques are important contributors to environmental pollution, and biological-based solutions have thus become progressively very popular. In particular, insect-based conversion of organic wastes represent eco-friendly tools, and the growth and development of insect species such as the black soldier fly have been tested and improved for a large diversity of organic wastes. However, organic wastes, including food wastes, may contain several pollutants such as heavy metals and catechol which could affect the bioconversion efficiency by incurring physiological costs that would be undetectable at the organismal level, i.e. have null to little effects on the life cycle of Hermetia illucens. In this context, assessments of antioxidant capacities can provide a rapid and low-cost evaluation of the capability of insects to handle exposure to heavy metals and catechol. Here, we aimed at measuring the physiological responses of the black soldier fly H. illucens grown on food wastes (kitchen, fruit or vegetable wastes) contaminated by cadmium, iron, lead or catechol. Biomarkers of oxidative stress (concentrations of hydrogen peroxide and protein carbonyls), non-enzymatic total antioxidant capacity (ascorbic acid amounts) and activity of enzymatic antioxidants (activities of superoxide dismutase and polyphenoloxidase) were measured from the gut of the larvae. We found no evidence of deleterious impacts of food waste contamination by catechol or heavy metals on H. illucens. In most experimental treatments, the array of physiological endpoints we measured for evaluating the degree of oxidative stress experienced by the larvae remained similar to controls. Possible physiological effects were reported for cadmium and catechol only, which tended to increase the oxidation of proteins and hydrogen peroxide in the larvae. Finally, our results suggested that the nature of the food waste could equally affect the physiological responses of the insect.

Preliminary Data on Essential and Non-essential Element Occurrence in Processed Animal Proteins from Insects

Insects represent a valuable and environmentally friendly protein alternative in food and feed. The Farm to Fork strategy encouraged the reintroduction of animal by-products in feed production to optimise recycling and to valorise under-used resources. In order to grant safe and valuable feed products, this study investigated the black soldier fly (BSF) (Hermetia illucens) chemical risk. Samples collected in different steps of production (8 samples of substrate for culturing, 7 samples of larvae, 15 samples of protein meal, 18 samples of spent substrate) were analysed for microessential elements (chromium, copper, iron, nickel, selenium and zinc) and inorganic contaminants (aluminium, arsenic, cadmium, lead, tin and vanadium) by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Microessential elements were found in the following order: Fe > Zn > Cu > Ni > Se > Cr (mg kg^-1). Non-essential element concentrations were found lower than the set limits according to the European Union Regulations. The growing demand for alternative protein sources for feed production could be partially compensated by black soldier fly (BSF) (Hermetia illucens) meal, as it appears a good source for high-quality proteins and microessential elements which play a pivotal role in animal growth. In the foreseeable future the current legislation and the official monitoring plans may be implemented and broaden, to focus and assess limits for upcoming matrices, and to ensure feed and food safety.

Detoxication and bioconversion of aflatoxin B1 by yellow mealworms (Tenebrio molitor): A sustainable approach for valuable larval protein production from contaminated grain

Yellow mealworm (Tenebrio molitor) is a supplementary protein source for food and feed and represents a promising solution to manage grain contaminated with Aflatoxin B₁ (AFB₁). In this study, AFB₁ present in different concentrations in wheat bran was treated and removed via bioconversion by yellow mealworm of different instars, with emphasis on the bioconversion performance and metabolism of AFB₁. Upon application of wheat bran spiked with 100 μg/kg AFB₁ to 5th-6th instar yellow mealworms, the conversion rate of AFB₁ was up to 87.85 %. Low level of AFB₁ (< 2 μg/kg) was accumulated in the larval bodies, and the survival rate, development and nutrition contents of yellow mealworm were not significantly affected. It was revealed that 1 kg of wheat bran contaminated with AFB₁ increased the weight of yellow mealworms from 138 g to 469 g, containing approximately 103 g of protein. The bioconversion of AFB₁ by yellow mealworms led to generation of 13 metabolites in the frass and 3 metabolites in the larvae. AFB₁ was detoxicated and removed via phase I metabolism comprising reduction, dehydrogenation, hydration, demethylation, hydroxylation, decarbonylation and ketoreduction, followed by phase II metabolism involving conjugation of amino acid, glucoside and glutathione (GSH). The toxicity of AFB₁ metabolites was deemed lower than that of AFB₁ according to their structures. This study provides a sustainable approach and theoretical foundation on using yellow mealworms for cleaner grain contamination management and valuable larval protein production via bioconversion of food and feed contaminated by AFB₁.

Potential Utilization of Insect Meal as Livestock Feed

Globally, the utilization of alternative protein sources in livestock feed has been extensively deliberated and established to be the best novel approach. Extensive research indicated that insects provide good opportunities as a sustainable, high quality, and low-cost component of animal feed. The use of insects in animal diet sounds to be the prospective opportunity leading to sustainability of animal feeds and meet the intensifying worldwide plea for livestock products. The value of these protein sources has, however, increased due to limited production, competition between humans and animals. The use of insects for feeding farmed animals represents a promising alternative because of the nutritional properties of insects and the possible environmental benefits, given the sustainability of this type of farming. Yet little has been documented about the nutrient composition of various insect meals, the impact of insect meal in the animal feed industry, safety, and attitude and willingness of farmers to accept insect-based animal feed and food. Therefore, this chapter seeks to document the potential utilization of insect meal as livestock feed.

Diet Fermentation Leads to Microbial Adaptation in Black Soldier Fly (Hermetia illucens; Linnaeus, 1758) Larvae Reared on Palm Oil Side Streams

Insects offer a promising alternative source of protein to mitigate the environmental consequences of conventional livestock farming. Larvae of the black soldier fly (Hermetia illucens; Linnaeus, 1758) efficiently convert a variety of organic side streams and residues into valuable proteins, lipids, and chitin. Here, we evaluated the suitability of two palm oil industry side streams—empty fruit bunches (EFB) and palm kernel meal (PKM)—as larval feed, and their impact on the larval gut microbiome. Among 69 fungal species we screened, Marasmius palmivorus, Irpex consors, and Bjerkandera adusta achieved the fastest growth and lignin degradation, so these fungi were used for the pretreatment of 7:3 mixtures of EFB and PKM. Larvae reared on the mixture pretreated with B. adusta (BAD) developed significantly more quickly and reached a higher final weight than those reared on the other pretreatments or the non-fermented reference (NFR). Amplicon sequencing of the BAD and NFR groups revealed major differences in the larval gut microbiome. The NFR group was dominated by facultatively anaerobic Enterobacteriaceae (typical of H. illucens larvae) whereas the BAD group favored obligately anaerobic, cellulolytic bacteria (Ruminococcaceae and Lachnospiraceae). We hypothesize that fungal lignin degradation led to an accumulation of mycelia and subsequent cellulolytic breakdown of fiber residues, thus improving substrate digestibility.

Mycotoxin Metabolism by Edible Insects

Mycotoxins are a group of toxic secondary metabolites produced in the food chain by fungi through the infection of crops both before and after harvest. Mycotoxins are one of the most important food safety concerns due to their severe poisonous and carcinogenic effects on humans and animals upon ingestion. In the last decade, insects have received wide attention as a highly nutritious, efficient and sustainable source of animal-derived protein and caloric energy for feed and food purposes. Many insects have been used to convert food waste into animal feed. As food waste might contain mycotoxins, research has been conducted on the metabolism and detoxification of mycotoxins by edible insects. The mycotoxins that have been studied include aflatoxins, fumonisins, zearalenone (ZEN), vomitoxin or deoxynivalenol (DON), and ochratoxins (OTAs). Aflatoxin metabolism is proved through the production of hydroxylated metabolites by NADPH-dependent reductases and hydroxylases by different insects. ZEN can be metabolized into α- and β-zearalenol. Three DON metabolites, 3-, 15-acetyl-DON, and DON-3-glucoside, have been identified in the insect DON metabolites. Unfortunately, the resulting metabolites, involved enzymes, and detoxification mechanisms of OTAs and fumonisins within insects have yet to be identified. Previous studies have been focused on the insect tolerance to mycotoxins and the produced metabolites; further research needs to be conducted to understand the exact enzymes and pathways that are involved.

Food waste bioconversion into new food: A mini-review on nutrients circularity in the production of mushrooms, microalgae and insects

The global challenge of feeding an ever-increasing world population is leading scientists' attention towards nutritious and sustainable foods whose production should have low impacts on environment, economy and society. In case the input feedstock can be waste nutrients, the label of such productions becomes even greener. Nutrients circularity is nowadays an important circular economy practice. This mini-review focuses on the valorisation of food waste as precious biomass to grow new food and feed. In particular, three functional edibles are discussed in the present paper: mushrooms, microalgae and insects. These foods are part of people diets since ages in certain areas of the world and the original aspect of their cultivation and breeding found on waste nutrients recovery is here reviewed. Proofs of such food waste biorefinery viability are already given by several researches featuring the main traits of a suitable growing medium: optimal pool of nutrients and optimal pH. However, lot of work still needs to be done in order to assess the optimal growth and cultivation conditions and the health security of the harvested/bred edibles. A SWOT factors analysis was performed.

[Survey of Arsenic/Heavy Metals and Pesticide Residues in Edible Insects for Human Consumption or Supplied in Japan]

Arsenic (As) and heavy metals (Cd, Hg, Pb, and Cu) and pesticide residues in 14 edible insects were investigated. The maximum levels of elements were 6.15 for As, 0.82 for Cd, 0.50 for Hg, 0.67 for Pb, and 297.7 ppm for Cu. Fenobucarb (or BPMC) has been quantified through GC- and LC-MS/MS analysis at a concentration of approximately 3 ppm. Further studies of the contaminants may help ensure the safety of edible insect consumption.

Yellow Mealworm and Black Soldier Fly Larvae for Feed and Food Production in Europe, with Emphasis on Iceland

Insects are part of the diet of over 2 billion people worldwide; however, insects have not been popular in Europe, neither as food nor as a feed ingredient. This has been changing in recent years, due to increased knowledge regarding the nutritional benefits, the need for novel protein production and the low environmental impact of insects compared to conventional protein production. The purpose of this study is to give an overview of the most popular insects farmed in Europe, yellow mealworm, Tenebrio molitor, and black soldier fly (BSF), Hermetia illucens, together with the main obstacles and risks. A comprehensive literature study was carried out and 27 insect farming companies found listed in Europe were contacted directly. The results show that the insect farming industry is increasing in Europe, and the success of the frontrunners is based on large investments in technology, automation and economy of scale. The interest of venture capital firms is noticeable, covering 90% of the investment costs in some cases. It is concluded that insect farming in Europe is likely to expand rapidly in the coming years, offering new proteins and other valuable products, not only as a feed ingredient, but also for human consumption. European regulations have additionally been rapidly changing, with more freedom towards insects as food and feed. There is an increased knowledge regarding safety concerns of edible insects, and the results indicate that edible insects pose a smaller risk for zoonotic diseases than livestock. However, knowledge regarding risk posed by edible insects is still lacking, but food and feed safety is essential to put products on the European market.

A systematic literature review on the effects of mycotoxin exposure on insects and on mycotoxin accumulation and biotransformation

Novel protein sources for animal feed are needed, and the use of insects as feed ingredient is explored. The insect production sector offers opportunities for a circular and sustainable approach to feed production by upgrading waste or side streams into high-quality proteins. However, potential food or feed safety issues should be studied in advance. Mycotoxins, such as aflatoxin B1, are natural contaminants commonly found in agricultural crops and have proven to be detrimental to the agricultural industry, livestock, and human health. This systematic review aims to provide a comprehensive overview of the published evidence on effects of mycotoxin exposure on insect growth and survival, mycotoxin accumulation within the insect body, and metabolization of various mycotoxins by insects. The review includes 54 scientific articles published in the past 55 years, in total covering 32 insect species. The main findings are the following: (1) Insects of the order Coleoptera show lower mortality after exposure to aflatoxin B1 when compared to Lepidoptera and Diptera; (2) effects of mycotoxins on larval growth and survival are less detrimental in later larval stages; (3) accumulation of mycotoxins was low in most insect species; (4) mycotoxins are metabolized within the insect body, the degree of which depends on the particular mycotoxin and insect species; (5) cytochrome P450s are the main family of enzymes involved in biotransformation of mycotoxins in some insect species. Results of this review support an optimistic outlook for the use of mycotoxin-contaminated waste streams as substrate for insect rearing.

Food Safety of Consuming Black Soldier Fly (Hermetia illucens) Larvae: Microbial, Heavy Metal and Cross-Reactive Allergen Risks

Black soldier fly (Hermetia illucens) larvae (BSFL) are a promising, sustainable source of nutrients, however, there is limited knowledge regarding the food safety of consuming BSFL. This study determined the safety of consuming BSFL for direct human consumption in terms of microbial, heavy metal and allergen content. Microbial counts were determined using ISO (International Organization for Standardization) methods, heavy metals were determined using inductively coupled plasma mass spectrometry and allergens were determined via Orbitrap mass spectrometry and ELISA (enzyme-linked immunosorbent assay) kits. Feed and killing method influenced the presence of Bacillus cereus (p = 0.011), and only the killing method influenced Escherichia coli (p < 0.00) and total viable count (TVC) (p < 0.00). Blanching resulted in a 3-log reduction in E. coli and a 3.4 log reduction in the TVC counts. Salmonella spp. and Listeria spp. were not detected in the BSFL samples. Heavy metals were detected although they were below maximum legal limits. Cross-reactive allergens, tropomyosin and arginine kinase, were detected in the BSFL samples, although the clinical significance requires research. The feed fed to the BSFL and blanching were found to influence the safety of consuming BSFL, highlighting the importance of incorporating sufficient decontamination steps, such as blanching, to ensure food safety.

Current permissible levels of metal pollutants harm terrestrial invertebrates

The current decline of invertebrates worldwide is alarming. Several potential causes have been proposed but metal pollutants, while being widespread in the air, soils and water, have so far been largely overlooked. Here, we reviewed the results of 527 observations of the effects of arsenic, cadmium, lead and mercury on terrestrial invertebrates. These four well-studied metals are considered as priorities for public health and for which international regulatory guidelines exist. We found that they all significantly impact the physiology and behavior of invertebrates, even at levels below those recommended as 'safe' for humans. Our results call for a revision of the regulatory thresholds to better protect terrestrial invertebrates, which appear to be more sensitive to metal pollution than vertebrates. More fundamental research on a broader range of compounds and species is needed to improve international guidelines for metal pollutants, and to develop conservation plans to protect invertebrates and ecosystem services.

Mycotoxin extraction from edible insects with natural deep eutectic solvents: a green alternative to conventional methods

Edible insects are widely consumed in Africa, Asia, Oceania and Latin America, but less commonly so in Western countries. Since the turn of the millennium, however, entomophagy has aroused growing interest worldwide in response to the increasing scarcity of food resources. In fact, edible insects can be a source of high-quality protein, and also of fat, energy, minerals and vitamins. However, the lack of regulatory guidelines for microbiologically or chemically hazardous agents potentially present in these new foods (e.g., mycotoxins) may make their consumption unsafe. In this work, we developed an environmentally friendly analytical method using natural deep eutectic solvents (NADES or natural DES) in combination with ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of six mycotoxins of great concern owing to their toxic effects on humans and animals (namely, fumonisin B₁, fumonisin B₂, T-2 toxin, HT-2 toxin, ochratoxin A and mycophenolic acid) in insect-based food products. The target mycotoxins were co-extracted from cricket flour by using the optimum DES composition (namely, a mixture of choline chloride and urea, in a 1:2 mole ratio, containing 15% water which resulted in the highest extraction recoveries for all toxins). An experimental design method (Fractional Factorial Design (FFD) was used to examine the influence of the operational variables DES volume and water content, amount of sample, extraction time and extraction temperature on the extraction efficiency for each mycotoxin. Under optimum conditions, extraction recoveries were close to 100% except for fumonisin B₂ (70%) and T-2 toxin (50%), with relative standard deviations (RSDs) below 13% in all cases. The proposed NADES-UHPLC-MS/MS method was validated in accordance with the European Commission 2002/657/EC and 2006/401/EC decisions, and used to determine the target compounds in cricket flour, silkworm pupae powder and black cricket powder.

Possibilities of the Development of Edible Insect-Based Foods in Europe

All over the world, a large proportion of the population consume insects as part of their diet. In Western countries, however, the consumption of insects is perceived as a negative phenomenon. The consumption of insects worldwide can be considered in two ways: on the one hand, as a source of protein in countries affected by hunger, while, on the other, as an alternative protein in highly-developed regions, in response to the need for implementing policies of sustainable development. This review focused on both the regulations concerning the production and marketing of insects in Europe and the characteristics of edible insects that are most likely to establish a presence on the European market. The paper indicates numerous advantages of the consumption of insects, not only as a valuable source of protein but also as a raw material rich in valuable fatty acids, vitamins, and mineral salts. Attention was paid to the functional properties of proteins derived from insects, and to the possibility for using them in the production of functional food. The study also addresses the hazards which undoubtedly contribute to the mistrust and lowered acceptance of European consumers and points to the potential gaps in the knowledge concerning the breeding conditions, raw material processing and health safety. This set of analyzed data allows us to look optimistically at the possibilities for the development of edible insect-based foods, particularly in Europe.

Cytochrome P450-mediated mycotoxin metabolism by plant-feeding insects

Mycotoxins are secondary metabolites produced primarily by filamentous fungi that when consumed cause pathological responses in animal hosts or consumers. Defined functionally rather than structurally, mycotoxins derive from numerous primary metabolic pathways. Through opportunistic or mutualistic associations, insect herbivores inflict damage that can predispose plants to infection by mycotoxin-producing phytopathogens, resulting in economically significant contamination. The few cytochrome P450 subfamilies implicated in mycotoxin detoxification by insects, including CYP6 and CYP9, are also known to detoxify phytochemicals. Some insect P450s bioactivate, rather than detoxify, mycotoxins, suggestive of an 'escalation' in arms-race interactions between these herbivores and fungi. Characterizing insect P450s that detoxify mycotoxins can be useful for developing biological remediation technologies and for ensuring the safety of insects reared for human or livestock consumption.

Use Them for What They Are Good at: Mealworms in Circular Food Systems

Future food systems must provide more food produced on less land with fewer greenhouse gas emissions if the goal is to keep planetary boundaries within safe zones. The valorisation of agricultural and industrial by-products by insects is an increasingly investigated strategy, because it can help to address resource scarcities and related environmental issues. Thus, insects for food and feed have gained increasing attention as a sustainable protein production strategy in circular food systems lately. In this article, we provide an overview on by-products, which have already been fed to T. molitor (mealworms), a common edible insect species. In addition, we investigate other by-products in Austria, which can be suitable substrates for T. molitor farming. We also provide an overview and discuss different perspectives on T. molitor and link it with the circular economy concept. We identify several future research fields, such as more comprehensive feeding trials with other by-products, feeding trials with mealworms over several generations, and the development of a standardized framework for insect rearing trials. In addition, we argue that due to their ability to convert organic by-products from agricultural and industrial processes into biomass in an efficient way, T. molitor can contribute towards resource-efficient and circular food and feed production. However, several hurdles, such as legal frameworks, need to be adapted, and further research is needed to fully reap the benefits of mealworm farming.

Dietary zinc enrichment reduces the cadmium burden of mealworm beetle (Tenebrio molitor) larvae

The industrial production of Tenebrio molitor L. requires optimized rearing and processing conditions to generate insect biomass with high nutritional value in large quantities. One of the problems arising from processing is a tremendous loss in mineral accessibility, affecting, amongst others, the essential trace element Zn. As a feasible strategy this study investigates Zn-enrichment of mealworms during rearing to meet the nutritional requirements for humans and animals. Following feeding ZnSO₄-spiked wheat bran substrates late instar mealworm larvae were evaluated for essential micronutrients and human/animal toxic elements. In addition, growth rate and viability were assessed to select optimal conditions for future mass-rearing. Zn-feeding dose-dependently raised the total Zn content, yet the Zn_larvae/Zn_{wheat bran} ratio decreased inversely related to its concentration, indicating an active Zn homeostasis within the mealworms. The Cu status remained stable, suggesting that, in contrast to mammals, the intestinal Cu absorption in mealworm larvae is not affected by Zn. Zn biofortification led to a moderate Fe and Mn reduction in mealworms, a problem that certainly can be overcome by Fe/Mn co-supplementation during rearing. Most importantly, Zn feeding massively reduced the levels of the human/animal toxicant Cd within the mealworm larvae, a technological novelty of outstanding importance to be implemented in the future production process to ensure the consumer safety of this edible insect species.

Social Representations of Insects as Food: An Explorative-Comparative Study among Millennials and X-Generation Consumers

Simple Summary

In recent years, a remarkable number of studies have investigated entomophagy from different perspectives. Nevertheless, the theoretical framework of social representations (SRs) has never been used. SRs are organized sets of opinions, knowledge, attitudes, and beliefs about a social object—such as novel foods—co-constructed and shared by a social group. The present research is the first attempt to study entomophagy in the theoretical and methodological framework of SRs. We followed a double trajectory corresponding to two different ways to imagine the contribution of SRs to entomophagy studies. The first one focuses on the role of SRs in the social construction of meanings attached to entomophagy and on their introduction in individuals’ and groups’ thinking frameworks. The second proposes SRs as predictors, even if non-deterministic, of consumers’ behaviors. The results stimulate consideration of social knowledge and cultural variables in food studies using the theoretical framework of SRs.

Abstract

The aim of the research here presented is to describe and compare the social representations of entomophagy co-constructed and circulating among different groups of consumers. Social representations theory (SRT) allows us to understand a social reality that the individual builds based on his own experience in everyday life symbolic exchanges, whose primary function is to adapt concepts and abstract ideas using objectification and anchoring processes. We carried out this research within the structural approach methodological framework. We explored the structure (central core and peripheral schemes) and the content (information, opinions, attitudes, and beliefs) of the social representations of entomophagy by using mixed methodological strategies (hierarchized evocations, validated scales, check-list, projective tool, open-ended questions). Data were processed employing different R packages. The main results show an essential role played by generative processes (objectification and anchoring) as well as cognitive polyphasia and thémata in the co-construction of the social representations of entomophagy. Data could help in understanding the sensory characteristics of “insects as food” that should be used or avoided, for example, in communication aimed to promote entomophagy.

Entomogenous fungi isolated from Cryptotympana atrata with antibacterial and antifungal activity

Although many entomogenous fungi have been discovered over the years, few studies on the crude extracts of fungi isolated from Cryptotympana atrata with antibacterial and antifungal activity were reported. In this study, total twenty entomogenous fungi were isolated for the first time. And among of them, two pure cultures were identified as Purpureocillium lilacinum and Aspergillus fumigatus with apparent morphology, microscopic identification and 18S rRNA gene sequence. The active strains were fermented to optimize in six different culture media at three different pH values. The antibacterial and antifungal activities of the metabolites were more potent and efficient in Fungal medium 3^# at a pH of 6.2 than in the other tested media or at the other tested pH values. Total seven human pathogens and one insect pathogen were used to evaluate the antibacterial and antifungal activity of crude extracts, among which 25% of the extracts exhibited antifungal activity against Verticillium lecanii, while 33.3% and 47.2% of the extracts exhibited antibacterial activity against the important human pathogens Staphylococcus aureus and Bacillus cereus, respectively. The range of the MICs was from 15.6 to 250 μg mL^-1, and 35% of the fungal metabolites exhibited antibacterial activity against Pseudomonas aeruginosa, Bacillus thuringiensis and Enterobacter aerogenes at 1000 μg mL^-1 except the previously described antibacterial activities. Furthermore, the phylogenetic relationships of the two identified fungi were also constructed. In brief, it is the first reporting about enthompathogenic fungi from Cryptotympana atrata and provides candidate strains with potential use as biological agents and against multidrug-resistant organisms.

Nutrition and health of edible insects

PURPOSE OF REVIEW

Elucidate the effect of insects as feed and food on nutrition and health of humans and animals.

RECENT FINDINGS

A new sector is developing of insects as food and feed. The academic interest is growing exponentially. In addition to their high nutritional values, there are also health benefits. These relate to prebiotic effects of insect products, such as chitin on humans and animals. Insects have a large reservoir of antimicrobial peptides. Some insect species have shown to have antioxidant properties.

SUMMARY

The increasing demand for meat and the limited amount of land availability prompt the search for alternative protein sources. Insects require less land and have a lower environmental impact than meat products. In addition to having a high nutritional value, they have also health benefits. Several edible insect species can be grown on organic side streams, in this way contributing to a circular economy. The number of scientific articles increased exponentially, and more than 290 start-ups are now engaging in its production and marketing. Food safety issues are not a major issue but need to be carefully checked when organic waste streams are used. The main strategies related to consumer issues are disguising the insects in familiar products and making them tasty.

Effects of heavy metals on the bioaccumulation, excretion and gut microbiome of black soldier fly larvae (Hermetia illucens)

The black soldier fly larvae (BSFL) have become a promising candidate for waste disposal and are an ideal feed source for animal nutrition. The uptake of heavy metals could influence the growth of BSFL, but the effects of heavy metal pressures on the gut microbiota of BSFL are largely uncharacterized. Here, we examine the influences of Cu and Cd on the growth and gut microbiota of BSFL as well as the distribution of accumulated heavy metals in the larvae and their feces. Exposure to Cu (from 100 to 800 mg/kg) and Cd (from 10 to 80 mg/kg) did not significantly inhibit the weight gain of BSFL. With elevated exposure doses, the contents of both Cu and Cd accumulated in the bodies and feces of BSFL were remarkably increased. In the BSFL feces, Cu mainly existed as residues, while Cd mainly existed as either water-soluble states (in the low-exposure groups) or residues (in the high-exposure groups). Cd was more readily enriched (47.1%-91.3%) than Cu (<30%) in vivo. More importantly, exposure to Cu and Cd remarkably altered the gut microbiota of BSFL, particularly in the phyla Proteobacteria, Firmicutes and Bacteroidetes. High exposure to the metals (i.e., Cu-800 and Cd-80 groups) substantially decreased the abundances of most of the dominant families, but significantly stimulated the enrichment of Brucellaceae, Enterobacteriaceae, Alcaligenaceae, Campylobacteraceae, and Enterococcaceae. Moreover, the bacterial diversity in the BSFL gut was significantly reduced following high exposure to the metals. These results may fill a gap in our knowledge of the effects of heavy metals on the intestinal microbiome of BSFL.

Evaluation of Biochemical Parameters of Rats Fed with Corn Flour Supplemented with Cricket (Acheta gossypii) Proteins

African staple diets are mainly of protein-deficient corn. Dried yellow corn was fermented, dried, ground and supplemented with 5% and 10% of cricket (Acheta gossypii) flour. A standard diet of 5% and 10% soybean proteins-based corn flour was also prepared. The diets were fed to albino rats for four weeks. Standard methods for the serum levels of alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT), total proteins (TP), and albumin were determined in albino rats using 5% and 10% soybean supplemented corn diets as standard diets. The serum levels of ALP, AST, ALP, TP, and albumin in the rats fed with cricket supplemented diets were in the range of the normal healthy animals but were significantly different from the cornflour and soybean supplemented diets such that the ALP and AST values of the rats fed on the cornflour significantly decreased over the soybean supplemented and cricket supplemented experimental diets. The ALT activity, TP, and albumin levels of the rats fed the cornflour, and the soybean supplemented diets were significantly lower than those fed on the cricket protein supplemented diet (p <0.05). Supplementing corn with crickets has shown improvement in the nutritional quality of corn, therefore, may be used to solve the malnutrition