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Heavy metals (Pb, Cd, Ni) in insect-based products for human consumption sold by e-commerce in the EU market: Occurrence and potential health risk associated with dietary exposure
... Among the various natural and anthropogenic contaminants impacting soils, aquatic environments, and food sources, heavy metal pollution is a global concern with severe consequences for human health and the environment. Heavy metals have been detected not only in soils and water bodies but also in food sources, including crops, meat, and dairy products [1][2][3]. The lack of clean, potable water affects billions of people worldwide and represents a critical issue that must be addressed, as consumption of contaminated water leads to numerous diseases and deaths each year [4,5]. ...
A novel green synthesis method was developed for sulfur-doped carbon dots (S-C-dots) using chicken egg white (CEW) and L-cysteine for the rapid and cost-effective detection of copper ions (Cu2+) in water. This one-pot, room-temperature, base-catalyzed approach eliminated the need for energy-intensive processes and purification steps, adhering to the principles of green chemistry. The synthesized S-C-dots were characterized using UV–Vis, FT-IR, fluorescence, EDS, XRD, and Z-potential analyses. Among the six samples tested, A060 demonstrated superior properties, achieving a detection limit of 3.3 ppb (52 nM) for Cu2+ in aqueous solutions. This study highlights the potential of S-C-dots as eco-friendly, accessible, and efficient tools for monitoring heavy metal contamination in drinking water, offering a promising solution to global water safety challenges.
... Traditionally, insects were consumed as whole entities, either dried or roasted; however, there has been a significant evolution in their culinary applications. Today, insect-based protein powders are gaining traction as versatile ingredients in energy bars, snacks, pasta, and baked goods, enhancing their nutritional profile and offering unique flavours [36]. Table 1 highlights how insectbased products have become increasingly specialized to serve multiple sectors (e.g., human food, animal feed, and agriculture), emphasizing the adaptability of insects as a sustainable protein source. ...
Farmed edible insects are considered a potential resource to help address food security concerns toward the year 2050. The sustainability (e.g., lower environmental impact), nutritional (e.g., high-quality proteins, essential amino acids, fiber, unsaturated fats, vitamins, and minerals) and health (e.g., antioxidant, antihypertensive, anti-inflammatory, antimicrobial, and immunomodulatory) benefits are the main reasons for the rise in interest for insects as alternative protein sources for food and feed production. Thus, edible insects can address the future global protein demand of an ever-increasing world population. In this context, several aspects related to their sustainability have been explored and addressed from an environmental perspective. This review describes the rationale for using insects as alternative protein sources and provides a comprehensive viewpoint, integrating economic, environmental, and social aspects into their sustainability framework toward addressing food insecurity concerns. For example, edible insects offer a more sustainable protein source comparable to, or even better than, that of conventional livestock. Considering their sustainability advantages, insects are noted for their lower impact on natural resources (e.g., water and agrarian land) and lower greenhouse gas emissions (e.g., carbon dioxide and methane). From a socioeconomic point of view, edible insects have lower production costs compared to conventional animal protein sources because of their high feed efficiency conversion, rapid growth rate, and short life cycles. Currently, the market for edible, farmed insects is becoming a significant economic activity that not only meets the needs of industry and consumers but also supports the ability of future generations to maintain a secure and sustainable community.
... The concept of 'safe enough' and how it can be determined has been a theme of the literature for over half a century (Fischhoff et al., 1978). However 'safe enough' is being reconsidered in more recent literature in terms of reducing and valorising food waste and by-products (Socas-Rodríguez et al., 2021); heavy metals in insect based products (Gori et al., 2025); and cultured meat (Siddiqui et al., 2022). Reflexive governance structures, for example, where artificial intelligence (AI) could be used to make autonomous decisions associated with food safety management, could be of value in determining multi-stakeholder perceptions of 'safe enough,' and it is important scientifically, and ethically critical, to embed governance aspects within risk assessment, risk management and risk acceptance processes . ...
... On the other hand, presence of trace elements from insect-based food products have been reflected in the literature; i.e., Sikora et al. [39] detected contents of Al and Pb in feed based on yellow mealworm, and Gori et al. [40] observed concentrations of Pb, Cd, and Ni in insect-based products sold by e-commerce in the EU market. ...
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.
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.
Current estimations showed that the number of people affected by hunger doubled in the last two years, reaching 9.8% of the global population. According to FAO, in order to satisfy the demand for food in the next few years, it will be necessary to double food production. Moreover, the call for a change in dietary patterns has been raised, showing how the food sector is responsible of 1/3 of climate change where meat-based diets or overconsumption of meat play an important role in the negative environmental impact. Consequently, there is a growing concern in how to achieve the goal of increasing food productions without exploiting environmental resources and to explore the production and use of alternative resources, such as insects. Insects are gaining interests both as food and feed not only to reduce the environmental costs in feed production for common livestock, but also to reduce farmers’ dependence on traditional protein sources.
In this work we aimed to provide an overview of the state-of-the-art upon insect studies, highlighting the most important results obtained from both an industrial and market perspective. The legislative framework concerning edible insects as food and feed is also analyzed, with the final purpose to highlight recent reforms, relevant case-law as well as unsolved regulatory challenges.
From a normative perspective, regulatory efforts are still required to fully take advantage of the potentialities of insects-industry. From a consumer point of view, consumers’ willingness to pay a premium is going to be a key issue for economic sustainability of the insect farming chain. To meet the food and feed security challenges, insects will have to be considered all-around, including applications in the food, feed, and other sectors.
We believe that this review is an important contribution to the field of food science and will be of interest to researchers, food industry professionals, and policymakers in order to prioritize research questions and help communicate scientific knowledge to a broader audience.
Simple Summary
Traditional and emerging topics bridging insects and public health are described because insects affect human and animal health. Addressing public health professionals, this paper aims to (i) outline and enforce the role of public health authorities in different sectors involving insects, health, food and feed, (ii) improve the rearing, management conditions and animal welfare of insects, and (iii) enhance research activities on different aspects of the insect-public health interface.
Abstract
Insects are, by far, the most common animals on our planet. The ubiquity and plethora of ecological niches occupied by insects, along with the strict and sometimes forced coexistence between insects and humans, make insects a target of public health interest. This article reports the negative aspects historically linked to insects as pests and vectors of diseases, and describes their potential as bioindicators of environmental pollution, and their use as food and feed. Both negative and positive impacts of insects on human and animal health need to be addressed by public health professionals who should aim to strike a balance within the wide range of sometimes conflicting goals in insect management, such as regulating their production, exploiting their potential, protecting their health and limiting their negative impact on animals and humans. This requires increased insect knowledge and strategies to preserve human health and welfare. The aim of this paper is to provide an overview of traditional and emerging topics bridging insects and public health to highlight the need for professionals, to address these topics during their work. The present and future role and activities of public health authorities regarding insects are analyzed.
The effects of population increase and food production on the environment have prompted various international organizations to focus on the future potential for more environmentally friendly and alternative protein products. One of those alternatives might be edible insects. Entomophagy, the practice of eating insects by humans, is common in some places but has traditionally been shunned in others, such as European countries. The last decade has seen a growing interest from the public and private sectors to the research in the sphere of edible insects, as well as significant steps forward from the legislative perspective. In the EU, edible insects are considered novel foods, therefore a specific request and procedure must be followed to place them in the market; in fact, until now, four requests regarding insects as a novel food have been approved. Insects could also be used as feed for livestock, helping to increase food production without burdening the environment (indirect entomophagy). Market perspectives for the middle of this decade indicate that most of the demand will be from the feed sector (as pet food or livestock feed production). Undoubtedly, this sector is gaining momentum and its potential relies not only in food, but also in feed in the context of a circular economy.
The processing of insects is paramount to deliver safe and high quality raw materials, ingredients and products for large-scale food and feed applications. Depending upon the nature of the initial material and the desired end product, the processing pathways vary and may include several unit operations currently already used in food and feed processing. Insect processing pathways can involve harvesting, pre-processing, decontamination, further processing, packaging and storage. Several traditional and industrial decontamination methods have been proposed for edible insects, which include smoking, drying, blanching/boiling, marination, cooking, steaming, toasting and their combinations. Further processing steps are employed to produce insect meal, insect flour or extracted insect fractions. Each operation will have a different impact on the chemical and microbiological properties of the final product. Novel food processing technologies (e.g. high pressure processing, pulsed electric field, ultrasound and cold plasma) have shown potential to modify, complement or replace the conventional processing steps in insect processing. These technologies have been tested for microbial decontamination, enzyme inactivation, drying and extraction. Further, these are considered to be environmentally friendly and may be implemented for versatile applications to improve the processing efficiency, safety and quality of insect based products. Future research focuses in insect processing are development of efficient, environmentally friendly and low-cost processes; waste minimisation and incorporation of by-products/co-products.
Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Food and Food Allergens (NDA) was asked to deliver an opinion on the safety of frozen and dried formulations from migratory locust (Locusta migratoria) as a novel food pursuant to Regulation (EU) 2015/2283. The term migratory locust refers to the adult of the insect species Locusta migratoria. The NF is proposed in three formulations i) frozen without legs and wings; ii) dried without legs and wings; iii) ground with legs and wings. The main components of the NF are protein, fat and fibre (chitin) in the dried form of the NF, and water, protein, fat and fibre (chitin) in the frozen form of the NF. The Panel notes that the concentration of contaminants in the NF depends on the occurrence levels of these substances in the insect feed. The Panel notes that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf-life. The NF has a high protein content, although the true protein levels in the NF are overestimated when using the nitrogen-to-protein conversion factor of 6.25, due to the presence of non-protein nitrogen from chitin. The applicant proposed to use the NF as frozen, dried and ground in the form of snack, and as a food ingredient in a number of food products. The target population proposed by the applicant is the general population. The Panel notes that considering the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The submitted history of use and toxicity studies from literature did not raise safety concerns. The Panel considers that the consumption of the NF might trigger primary sensitisation to L. migratoria proteins and may cause allergic reactions in subjects with allergy to crustaceans, mites and molluscs. Additionally, allergens from the feed may end up in the NF. The Panel concludes that the NF is safe under the proposed uses and use levels.
Purpose
Climate change and global population growth are threatening the sustainability of hospitality food systems. Foodservice organizations are seeking an optimal solution for this problem. The United Nations Food and Agriculture Organization proposed edible insects as a solution, yet the “yuck” factor discourages consumers from actively endorsing this option. Thus, this study aims to find ways to increase consumer acceptance of edible insects.
Design/methodology/approach
A 2 (message framing: hedonic vs utilitarian) × 2 (celebrity endorsement: absence vs presence) × 2 (social support: low vs high) between-subjects factorial design experiment was conducted.
Findings
The significant three-way interaction effects show that when celebrity endorsement is absent, there is no difference in restaurant advocacy (RA) and experience satisfaction between utilitarian and hedonic message framing, regardless of low (vs high) social support. However, when celebrity endorsement is present and social support is not lacking, a hedonic (vs a utilitarian) message had more significant effects on dependent variables. Conversely, when celebrity-endorsed messages receive high social support, utilitarian (vs hedonic) messages had a more substantial effect on the outcome variables.
Originality/value
This study contributes to alternative protein and associated consumer psychology and hospitality marketing literature by introducing marketing strategies for edible insects. By demonstrating the three-way interaction effects of message framing, celebrity, endorsement and social support on RA and experience satisfaction, this study could demonstrate some boundary conditions to consider when applying celebrity endorsement strategies (e.g. message framing and social support). Also, by addressing the effects of social support, this study builds upon the lack of hospitality literature on online social support.
Edible insects are a novel food in most countries; their popularity is growing because of their high-protein and low-fat content, ease of cultivation, and small environmental impact. To our knowledge, this is the first report that addresses both microbiological and chemical hazards in edible insects. Samples were collected from retail stores or purchase through e-commerce. A total of 51 samples of dried whole insects or insect powder were tested for Escherichia coli, which serves as an indicator of the overall sanitation conditions throughout the food production chain, and the bacterial pathogen Salmonella spp. Neither Salmonella spp. nor E. coli (>100 CFU/g) was found in the samples analyzed. A total of 43 samples of crickets (protein bars, powders, flour, and whole insects) and 4 samples of silkworm (whole insects) were analyzed for up to 511 pesticides. Of these, 39 samples contained up to four pesticides; 34 samples were compliant and 5 samples were noncompliant with Canadian regulations. Seven pesticide residues were detected, with glyphosate and its metabolite, aminomethylphosphonic acid, as the predominant residues. Nineteen of the samples tested for pesticides were also analyzed for arsenic, cadmium, mercury, and lead; there was insufficient material remaining to allow testing of pesticides and metals. The positive rates for arsenic, cadmium, lead, and mercury were 100, 79, 58, and 74%, respectively. The detected concentrations ranged from 0.030 to 0.34 mg/kg for arsenic, from 0.031 to 0.23 mg/kg for cadmium, 0.019 to 0.059 mg/kg for lead, and from 0.94 to 28 μg/kg for mercury. Based on the lack of detection of microbiological contamination, and the positive rates and levels of pesticides and metals observed in the products, Health Canada determined that all insect products analyzed were safe for human consumption. This is a limited study; the Canadian Food Inspection Agency will continue to monitor this novel food.
HIGHLIGHTS
Owing to modern-day urbanization and industrial activities, heavy metal pollution and its environmental impact have drawn the attention of the scientific community towards itself. Among all the heavy metals, cadmium is known to have no biological function, and its presence harms almost all life forms. Cadmium (Cd) has natural and anthropogenic sources of entry into the ecosystem. It is non-biodegradable and is present in different trophic levels in the food chain. The availability, bio-accessibility, and accumulation of Cd in soil-plant systems are the main drivers of its transfer to different trophic levels via diverse routes. In the human system, bioaccumulation of Cd disrupts the antioxidant defense system due to induced oxidative stress as a result of reactive oxygen species (ROS) generation, which further causes different ailments. This review provides an update on the effects of Cd exposure on the soil-plant system, food safety, and human health, focusing on the various mechanisms involved in cellular or molecular alterations.
Edible insects have gained an increasing interest as a food product in recent years. They may represent an alternative source of protein and micronutrients compared to conventional meat sources. Thus the objective of this work was to determine the nutritional value as well as the chemical and microbiological contamination for a better evaluation of the risk/benefit of yellow mealworm larvae consumption. These larvae have a nutritional value (10.4% of fat and 13.7% of protein) similar to conventional meat sources. Their main fatty acids were oleic (37.8%) and linoleic (33.2%). The results showed these larvae fulfill the requirements for essential amino acids (all were above 100% of the daily contribution), with the exception of lysine. Our findings also showed that T. monitor larvae are an excellent source of minerals like phosphorus, magnesium and zinc (114%, 109 to 128% and 117% above RDI). In spite of having a low contribution of potassium and iron (16–17% and 20% of RDI), the lower sodium content is an advantage in terms of human health since high intake increases blood pressure. Mercury and lead values were below the detection limit and cadmium level was 0.10 mg/kg. Yellow mealworm larvae had high bacterial loads but no pathogenic bacteria were detected. Starvation for eight days at 5 °C reduced the total counts of all microorganisms, specially yeasts and total mesophilic anaerobic spore-forming bacteria.
The European Commission asked EFSA to update its previous Opinion on nickel in food and drinking water, taking into account new occurrence data, the updated benchmark dose (BMD) Guidance and newly available scientific information. More than 47,000 analytical results on the occurrence of nickel were used for calculating chronic and acute dietary exposure. An increased incidence of postimplantation loss in rats was identified as the critical effect for the risk characterisation of chronic oral exposure and a BMDL10 of 1.3 mg Ni/kg body weight (bw) per day was selected as the reference point for the establishment of a tolerable daily intake (TDI) of 13 lg/kg bw. Eczematous flare-up reactions in the skin elicited in nickel-sensitised humans, a condition known as systemic contact dermatitis, was identified as the critical effect for the risk characterisation of acute oral exposure. A BMDL could not be derived, and therefore, the lowest-observed-adverse-effect-level of 4.3 lg Ni/kg bw was selected as the reference point. The margin of exposure (MOE) approach was applied and an MOE of 30 or higher was considered as being indicative of a low health concern. The mean lower bound (LB)/upper bound (UB) chronic dietary exposure was below or at the level of the TDI. The 95th percentile LB/UB chronic dietary exposure was below the TDI in adolescents and in all adult age groups, but generally exceeded the TDI in toddlers and in other children, as well as in infants in some surveys. This may raise a health concern in these young age groups. The MOE values for the mean UB acute dietary exposure and for the 95th percentile UB raises a health concern for nickel-sensitised individuals. The MOE values for an acute scenario regarding consumption of a glass of water on an empty stomach do not raise a health concern.
In recent years, the consumption of insects, or entomophagy, has produced an increasing interest amongst scientists and ecologists as a potential source of animal protein. Eating insects is also interesting in terms of low greenhouse gas emissions and low land use. In contrast to tropical countries, where most of the 2000 edible insect species are traditionally consumed, the concept of eating insects is still new to Western culture and diet. Culture and eating habits exert a great influence on what is considered edible in the Mediterranean area, especially in Italy, where the preservation of culinary traditions is a predominant factor affecting dietary behaviour. The purpose of this narrative paper is to provide an overview of the main topics related to entomophagy. The introduction presents some information about the nutrient content and safety aspects, the second part summarises the cultural acceptance of insect in the world, while the role of food neophobia on the intention to consume insects in Italy is focused on in part three. The discussion displays important viewpoints of previously published studies and based on these perspectives it can be concluded that the Italian diet is still clearly influenced by local tradition. In conclusion, in order to introduce insects into the Italian diet, psychological motivation has to be enhanced.
In recent years, there has been a growing interest in the novel food market due to the growing demand for protein-rich food and the diversification of the protein sources currently used. The edible insect and insect based-food sector has recently experienced an increase in the quantities produced and traded. This increase has occurred thanks to awareness-raising actions and the development of European regulations. The limited development of this sector does not permit in-depth market and business analyses, since it is still in formation, which means that it is still a relatively unexplored field of study, especially on the European scene. The objective of this study is to carry out a preliminary investigation of the consistency, typology and product assortment of the companies located in the European Union and which are focused on the production and marketing of insect-based products. The survey was performed through the investigation of the E-commerce catalogues and Internet websites of the companies. The study also focuses on the main insect species used, the origin of the raw material used and the prices of products currently available on the European market. The results show that companies are mainly located in the northern European countries and that the most used distribution channels are the E-commerce websites, compared to physical retail outlets. Most companies also buy their raw material from third party companies, even non-European ones, and then process or only resell the product. The products which sold the most were whole insects or insect meal, mainly based on Tenebrio molitor or Acheta domesticus. Prices showed a high variability, in particular related to the species used and how it is packaged.
Background:
Nickel (Ni) oral consumption may elicit systemic reactions in patients affected by systemic nickel allergy syndrome (SNAS), including gastrointestinal symptoms, which in turn are associated with gut dysbiosis. We evaluated the effects of a low-Ni diet alone or in combination with the oral consumption of appropriate probiotics on Ni-sensitivity and urinary dysbiosis markers in SNAS patients.
Methods:
n = 51 patients with SNAS and concomitant intestinal dysbiosis were enrolled in the study. According to the urinary indican/skatole levels, quantified through a colorimetric and a high-performance liquid chromatographic method, respectively, patients were assigned to a dysbiosis type/grade and followed a low-Ni diet for three months. Along with the diet, 22 patients also consumed probiotics based on the dysbiosis type. In particular, a Lactobacilli- or Bifidobacteria-containing formulation was administered to patients with fermentative or putrefactive dysbiosis, respectively, while a broad-spectrum probiotic formulation containing both Lactobacilli and Bifidobacteria was administered to patients with mixed dysbiosis. After three months, patients were invited to repeat the Ni-stimulation and the dysbiosis tests.
Results:
The fermentative dysbiosis group represented the largest group followed by the mixed dysbiosis group, while only two patients had putrefactive dysbiosis. Overall, at three months of treatment in general (diet alone with or without probiotics), the Ni-sensitivity and dysbiosis levels were strongly ameliorated. The association of a low-Ni diet with a specific probiotic oral supplementation was significantly more effective in decreasing dysbiosis levels or reaching eubiosis than with diet alone.
Conclusion:
Our results, while confirming the benefits of a low-Ni diet in SNAS patients, strongly support that appropriate adjuvant treatment with probiotics significantly helps to improve intestinal dysbiosis or restore a healthy microbiota.
Developments in agriculture are a main driver for biodiversity loss, in which livestock play a major role through pastures and feed crop cultivation. Addressing biodiversity loss is challenging due to the broad definition of and the multitude of indicators for biodiversity. We reviewed scientific literature assessing effects of livestock on biodiversity in Europe, to provide an overview of general characteristics of these studies and their indicators for biodiversity. The search was performed in SCOPUS and Web of Science and yielded 857 records after deduplication, which was narrowed down to 131 articles that assessed biodiversity impacts of livestock in Europe. Analysis of these articles focused on general characteristics of the research (i.e. context, scale, species, function of livestock, approach), indicators used, and the general conclusion regarding the impact of livestock on biodiversity. The majority of articles studied biodiversity in France, UK, Italy, Germany and Spain; and studied the direct impact of grazing cattle and sheep on biodiversity at field scale. Indirect impacts of livestock on biodiversity through feed production were assessed in few studies. In about one third of the studies, the function of livestock was not related to food production, but to conservation of open landscapes through grazing. We found a large variety of indicators used to assess the impact of livestock on biodiversity. The indicators were divided in seven clusters: 1) DNA, breeds, populations, 2) abundance and richness, 3) traditional diversity indices, 4) novel diversity indices, 5) composition and function, 6) structure and habitats, and 7) qualitative scoring systems. The majority of studies included the indicators abundance and richness, although studies differed in the plant or animal species studied. Indicators used differed across scales and between functions of livestock. Studies with a conservation function of livestock more often used indicators from clusters 5 and 6 than studies with a food production function. A positive impact of livestock on biodiversity was often found in studies with a conservation function, whereas a negative impact of more intensive livestock was often found in studies with a food production function. The identified indicators for biodiversity were connected to different assumptions and values, and therefore answer different questions and present different conclusions regarding the state of biodiversity. This review provides insight in biodiversity assessments of livestock across scales and purposes; highlights that few studies linked livestock to their indirect impacts on biodiversity; and stresses that one should be critical about the indicators used for biodiversity.
Nickel is a transition element extensively distributed in the environment, air, water, and soil. It may derive from natural sources and anthropogenic activity. Although nickel is ubiquitous in the environment, its functional role as a trace element for animals and human beings has not been yet recognized. Environmental pollution from nickel may be due to industry, the use of liquid and solid fuels, as well as municipal and industrial waste. Nickel contact can cause a variety of side effects on human health, such as allergy, cardiovascular and kidney diseases, lung fibrosis, lung and nasal cancer. Although the molecular mechanisms of nickel-induced toxicity are not yet clear, mitochondrial dysfunctions and oxidative stress are thought to have a primary and crucial role in the toxicity of this metal. Recently, researchers, trying to characterize the capability of nickel to induce cancer, have found out that epigenetic alterations induced by nickel exposure can perturb the genome. The purpose of this review is to describe the chemical features of nickel in human beings and the mechanisms of its toxicity. Furthermore, the attention is focused on strategies to remove nickel from the environment, such as phytoremediation and phytomining.
Larvae of Tenebrio molitor L. (Coleoptera: Tenebrionidae) are particularly suitable as novel food for the human consumption; nevertheless, there are some potential safety risks linked with insect consumption. In this study we investigated the presence of Cd, Pb, Ni, As, Hg in new feeding substrates coming from solid residues generated by olive fruits processing, called olive-pomace, and their influence on the metal content in larvae of T. molitor. Morover, bioaccumulation factor and the mercury-selenium balance were evaluated. Analyses were carried out via graphite furnace atomic absorption spectrophotometry for Cd, Pb, Ni, As and Se, and via Direct Mercury Analyzer for Hg. All metal concentrations found in feeding substrates were below the legal limit of undesirable substances in animal feed (2002/32/EC). Concentrations in larvae were in the range (mg kg 1 wet weight): Cd 0.008-0.016, Pb 0.063-0.079, Ni 0.03-0.63, As 0.021-0.023, Hg 0.12 ⇥ 10 3-0.49 ⇥ 10 3 , and Se 0.057-0.085. Statistically significant correlation between metal content in feeding substrates and in larvae was evidenced only for Hg, which bioaccumulates. Se protects from mercury toxicity, with a Selenium Health Benefit Value (HVB Se) of > 0. Overall, our results indicate that the risk of exposure to metals from consumption of mealworm larvae is relatively low and in compliance with European Union regulations.
During the last five years the scientific knowledge on insects as food and feed has been growing exponentially. At the same time, the industrial sector is increasingly engaged in rearing, processing and marketing of edible insects. Considerable attention is given to the black soldier fly as it can convert organic waste streams and transform it into several feed, food and industrial products. The farming of insects has an environmental impact which is lower than that of livestock species. The profitability of industrial production of insects as feed depends very much on the availability and applicability of cheap non-utilised side-streams. Microbial communities and their relationship with insects deserve full attention as it may help in the conversion of organic side streams of low economic value. Nutrition and health benefits for animals and humans need further exploration, also considering that insects have the largest anti-microbial peptide reservoir of all animals. Plant health can also be promoted by using chitin-containing leftover substrates as fertiliser. As insects have only recently been considered as food or feed, legislation trails developments. Therefore, politicians need to be assured that rearing and processing techniques are such that insect products are guaranteed free of chemical and microbial contaminants. Consumers are becoming more and more aware that insects as food are a viable option. Insects need to be processed into ingredients, that can be applied for safe and appetising products. The insect sector is maturing fast, but still faces many challenges, which can only be met when all stakeholders closely cooperate.
Edible insects as an alternative source of protein are discussed as an important contribution to future feed and food security. However, it has to be ensured that the consumption is non-hazardous. This systematic review summarizes findings concerning contaminations of insects with mycotoxins and heavy metal ions (SciFinder, Pubmed, until 26 June 2019). Both kinds of contaminants were reported to reduce growth performance and increase mortality in insects. There was no evidence for accumulation of various mycotoxins analyzed in distinct insect species. However, further research is necessary due to limitation of data. Since the gut content contributes relevantly to the total body burden of contaminants in insects, a starving period before harvesting is recommended. Contrary, accumulation of heavy metal ions occurred to a varying extent dependent on metal type, insect species, and developmental stage. Examples are the accumulation of cadmium (black soldier fly) and arsenic (yellow mealworm). The reported species-specific accumulation and metabolism patterns of contaminants emphasize the importance to assess potential safety hazards in a case-by-case approach. Subject to regular monitoring of contaminants, the general ban in the European Union to use waste in animal feed should also be questioned regarding insect farming.
This study provides a framework of the factors predicting the intention of eating an insect-based product. As part of the study, a seminar was carried out to explore how the provision of information about ecological, health, and gastronomic aspects of entomophagy would modify consumer beliefs regarding insects as food. Before and after the informative seminar, two questionnaires about sociodemographic attributes and beliefs about the consumption of insects as food were given. Participants were then asked to carry out a sensory evaluation of two identical bread samples, but one was claimed to be supplemented with insect powder. Results showed that perceived behavioral control is the main predictor of the intention, followed by neophobia and personal insect food rejection. The disgust factor significantly decreased after the participants attended the informative seminar. Sensory scores highlighted that participants gave “insect-labelled” samples higher scores for flavor, texture, and overall liking, nevertheless, participants indicated that they were less likely to use the “insect-labelled” bread in the future. Our findings provide a better understanding of insect food rejection behavior and help to predict the willingness to try insect-based products based on some important individual traits and information.
Insects are part of the human diet in many parts of the world. Their nutritional value is widely recognized. Currently, most edible insects are harvested from the wild, although semi‐domestication and indoor farming have increased insect availability and the sustainability of production. In traditional cultures, insects are processed in a number of ways (steaming, roasting, smoking, frying, stewing, and curing, among others) to improve their sensory and nutritional qualities as well as their shelf‐life. In order to increase consumer interest in the West, various technologies have been developed that are aimed primarily at using insects as ingredients in a non‐recognizable form, such as powders or flour. These technologies include drying (sun‐drying, freeze‐drying, oven‐drying, fluidized bed drying, and microwave‐drying) and new processing methods (ultrasound‐assisted extraction, cold atmospheric pressure plasma, and dry fractionation) designed mainly for protein, fat, and/or chitin extraction. Insect‐based ingredients are sold for the production of cookies, chocolates, tortilla‐style chips, and other snacks. This review focuses on edible insect production, processing technologies, and commercialization using strategies ranging from traditional to novel as a sustainable approach for improving food security worldwide.
Heavy metals are naturally existing elements that have relatively high atomic weight and a minimum density five times the density of water. Heavy metals have extensive applications in industries, homes, agriculture and medicine, leading to their wide distribution in the environment. Most heavy metals are reported to be highly toxic. They also have numerous exposure routes, including ingestion, inhalation, and dermal absorption, subsequently inducing some health effects resulting from human and heavy metals contact. The implications of heavy metals with regards to children’s health have been noted to be more severe compared to adults. The element’s harmful consequences on children health include mental retardation, neurocognitive disorders, behavioral disorders, respiratory problems, cancer and cardiovascular diseases. Much attention should be given to heavy metals because of their high toxicity potential, widespread use, and prevalence. This review therefore examines the exposure routes and health effects of mercury (Hg), lead (Pb), chromium (Cr), cadmium (Cd), and barium (Ba) on children. In addition, their toxic mechanisms are elucidated.
Chemistry and Human Health, Division VII of the International Union on Pure and Applied Chemistry (IUPAC), provides guidance on risk assessment methodology and, as appropriate, assessment of risks to human health from chemicals of exceptional toxicity. The aim of this document is to describe dose-response relationships for the health effects of low-level exposure to cadmium, in particular, with an emphasis on causation. The term “cadmium” in this document includes all chemical species of cadmium, as well as those in cadmium compounds. Diet is the main source of cadmium exposure in the general population. Smokers and workers in cadmium industries have additional exposure. Adverse effects have been shown in populations with high industrial or environmental exposures. Epidemiological studies in general populations have also reported statistically significant associations with a number of adverse health effects at low exposures. Cadmium is recognized as a human carcinogen, a classification mainly based on occupational studies of lung cancer. Other cancers have been reported, but dose-response relationships cannot be defined. Cardiovascular disease has been associated with cadmium exposure in recent epidemiological studies, but more evidence is needed in order to establish causality. Adequate evidence of dose-response relationships is available for kidney effects. There is a relationship between cadmium exposure and kidney effects in terms of low molecular mass (LMM) proteinuria. Long-term cadmium exposures with urine cadmium of 2 nmol mmol
Insects have potential as a novel source of protein in feed and food production in Europe, provided they can be used safely. To date, limited information is available on the safety of insects, and toxic elements are one of the potential hazards of concern. Therefore, we aimed to investigate the potential accumulation of cadmium, lead and arsenic in larvae of two insect species, Tenebrio molitor (yellow mealworm) and Hermetia illucens (black soldier fly), which seem to hold potential as a source of food or feed. An experiment was designed with 14 treatments, each in triplicate, per insect species. Twelve treatments used feed that was spiked with cadmium, lead or arsenic at 0.5, 1 and 2 times the respective maximum allowable levels (ML) in complete feed, as established by the European Commission (EC). Two of the 14 treatments consisted of controls, using non-spiked feed. All insects per container (replicate) were harvested when the first larva in that container had completed its larval stage. Development time, survival rates and fresh weights were similar over all treatments, except for development time and total live weight of the half of the maximum limit treatment for cadmium of the black soldier fly. Bioaccumulation (bioaccumulation factor > 1) was seen in all treatments (including two controls) for lead and cadmium in black soldier fly larvae, and for the three arsenic treatments in the yellow mealworm larvae. In the three cadmium treatments, concentrations of cadmium in black soldier fly larvae are higher than the current EC maximum limit for feed materials. The same was seen for the 1.0 and 2.0 ML treatments of arsenic in the yellow mealworm larvae. From this study, it can be concluded that if insects are used as feed materials, the maximum limits of these elements in complete feed should be revised per insect species.
Purpose
This article examines the influence of marketing-controlled external motivators of impulse buying behaviour of snack foods in cafeterias among young students.
Design/methodology/approach
A questionnaire was used to inquire a sample of 200 young consumers about their impulse buying behaviour in cafeterias. The resulting data was submitted to an in-depth four-stage quantitative analysis.
Findings
The results show that there is not a unique profile of impulse buying behaviour and that young consumers can be effectively segmented in five groups according to their impulsive buying behaviour of snack foods using the eight factors revealed in the exploratory factor analysis. A new segment of health/nutrition-conscientious impulsive consumers was uncovered and characterized.
Research limitations/implications
The major constraints of this study are the use of a non-probability convenience sampling design and sample size. Future studies should include other products and a more heterogeneous sample. The study represents a good starting point for further debate on impulsive buying behaviour.
Practical implications
Most of the research done in this area has focused on supermarket environment neglecting other types of retail store. Companies could benefit from the current study as it provides them with information that can be used to improve their marketing strategies directed towards this specific market. Additionally, the findings can also help the development of public health policies better tailored to prevent overweight and obesity associated to snack food consumption.
Originality/value
The study extends the current body of knowledge by examining the applicability and relevance of external motivators of impulse buying behaviour to a significantly different retail environment.
(http://www.emeraldinsight.com/journals.htm?issn=0007-070x&volume=115&issue=9&articleid=17092889&show=abstract)
Copper and cadmium budgets were studied for a model insect herbivore/host plant system comprising the oligophagous leaf-chewing grasshopper (Locusta migratoria) feeding on Zea mays (Gramineae). Fifth instar larvae were fed, for between 5 and 20 days, on maize foliage contaminated with either copper, cadmium or on control foliage containing no excess metal. Male and female locusts fed on copper-treated maize retained 45 and 42% of ingested copper respectively, figures not significantly different from the 41 and 33% retained on untreated maize. Remaining copper was egested with the faeces. Locusts fed on copper-treated maize showed an increase of 27% in body copper burden compared with those on the control diet: the increase was independent of time on the diet. Female locusts retained 33% and males 21% of ingested cadmium. Faecal cadmium levels were elevated, and accumulation in both sexes was proportional to time on the Cd-enriched diet. For both copper and cadmium, some ingested metal probably passed directly through the locust gut, bound to undigested food material. Results suggest that grasshoppers may effectively regulate excess dietary copper, but are unable efficiently to regulate cadmium.
Modern food production accounts for over 25% of human greenhouse gas emissions, predominantly from animal-related products. Climate change calls for transforming food and feed industries. Edible insects are attracting attention as an alternative low-carbon footprint source of protein. However, questions remain about their total nutritional value and some safety concerns. This study analyzed the content of essential, toxic, and rare earth elements (REEs) in insect-based food and feed products commercially available in the European Union. In general, the content of macro- and microelements decreased in the following order: K>Na>P>Ca>Mg, and Zn>Fe>Cu>Mn>Mo>Se>Cr>Co. The highest mineral content was found in products based on house cricket. The level of toxic elements was below the allowance thresholds in foodstuffs. Increased content of Al and Pb was found in feed based on yellow mealworm (18.6 and 10.3 mg/100 g, respectively). REEs were not abundant (median 6.6 µg/100 g). The highest content of REEs was observed in feed products (133 µg/100 g). These results demonstrate that insect-based food can have favourable mineral content with low metal, metalloid, and REEs contamination levels, not posing any safety concerns. However, their elevated content in a single feed product advocates for further studies to understand the potential risk of introducing toxic elements into the food chain.
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.
Entomophagy is proclaimed as a sustainable nutritional strategy due to the high protein content in edible insects. As it turns out, it may also represent an effective tool for increasing dietary intake of nutrients that are frequently deficient. Cricket powder (CP) appears to be the simplest way. The objectives of this work were to determine the contents of fourteen minerals in CPs and in insect species namely, house cricket, yellow mealworm, desert locust, and superworm. To assess these insect species as sources of minerals with respect to the dietary recommended values (DRV) for some minerals, and to determine mineral enrichment level of some recipes with using CP. Samples were analyzed by means of high-resolution continuum source graphite furnace atomic absorption spectrometry and flame atomic absorption/emission spectrometry. These insect species can be considered as a uniform source of Fe. The species of house cricket, yellow mealworm, and desert locust would provide more than the DRV for Zn, Cu, and P. Replacing 10 % of the wheat flour with CP in bread and pasta recipes increases Zn content by 92–107 %. Finally, the low Cd and Pb contents indicate that the consumption of the given insect species presents no risk.
Edible insects and their ingredients are considered as a novel, sustainable and high-quality nutritional source for their potential use as food and feed. However, they are highly oxidizable and potentially unsafe. Dehydration of insects removes moisture and extends their shelf life. Moreover, it is considered as a prerequisite and/or pretreatment for some extraction technologies for ingredient production. Drying technologies (sun drying, smoke drying, roasting, freeze drying and oven drying) have been used to dry insects, both at a laboratory and industrial level. Different drying pretreatments (thermal blanching, microwave-assisted drying and pulsed electric field) have been explored to improve the final quality of the insect products, extending their shelf life and reducing total energy consumption. Therefore, this article aimed to review the current research available in edible insect drying processing technologies, addressing their effectiveness and their influence over different quality parameters such as protein/lipid extraction efficiency, sensory characteristics of the final products, microbiological safety, shelf life and their impact on bioactive compounds.
The interest in eating insects has grown in Western countries. Insects are on the market in some European countries due to the reinterpretation of EU legislation. In this study, house crickets (Acheta domesticus) were reared with two homemade and one commercial feed with different chemical compositions. Commercial chicken feed, which contained the highest levels of protein and minerals, produced the biggest and the most protein- and mineral-containing crickets. The protein content varied between 50.2 and 64.2 g/100 g (dry weight, DW). The examination of the amino acid profiles showed that the feed had a smaller effect on them than the amount of protein. Crickets, which received the most carbohydrate-rich feed, were highest in fat and lowest in protein. The fat content of all crickets was high (25.0–33.7 g/100 g, DW), and an average fatty acid profile was 40% saturated fatty acids (SFAs), 31% monounsaturated fatty acids (MUFAs), and 27% polyunsaturated fatty acids (PUFAs). A cricket’s diet has a significant effect on its composition.
Disgust, social influence, and moral concern seem to play a pivotal role in insect consumption. Research examining these factors, particularly in the UK, is currently lacking. As a result, two studies were conducted to examine the perceived barriers and benefits of insect consumption, and how disgust can be counteracted. First, a cross-sectional study (N = 600) showed that disgust and moral concerns were unique predictors of individual’s willingness to consume insect products. Second, we conducted an experiment (N = 519) to examine whether knowledge that someone else consumes an insect-based product impacts one’s own willingness to consume insects. In this study we replicated Hartmann, Ruby, Schmidt, and Siegrist (2018) methodology of giving information about an insect consumer but added details about the individuals’ occupation and what type of product they consumed, examining how these factors impacted individual’s willingness to consume insect-based products. We found that this information did not impact willingness to consume; however, it did influence feelings of disgust and perceived acceptability. This study also replicated the first study by demonstrating that disgust and moral concern are barriers to insect consumption. We hope the current findings trigger future research to examine how disgust can be counteracted, and to better understand the role of moral concern in insect consumption.
Cadmium (Cd) is a toxic heavy metal with no known biological functions in the human body. Due to a considerably long biological half-life and very low rate of excretion, accumulation of Cd in different body organs (eg, liver, kidney, and testes) over time is associated with perturbed functioning of these organs. Recent studies have shown the extreme sensitivity of the testes to Cd toxicity. In testes, Cd has been reported to induce oxidative stress, apoptosis of spermatogenic cells, reduction in androgen production and sperm functions. Moreover, Cd in combination with other environmental toxicants may be responsible for the declining fertility of males in both animals and humans. Pinpointing how Cd toxicity affects various testicular processes will be imperative for the development of preventative measures to promote fertility among males. Therefore, in the present review, we summarize the recent findings related to the Cd-induced oxidative toxicity, apoptotic toxicity, steroidogenic toxicity, and spermatotoxicity, along with their possible mechanisms in testicular tissue of different animal species. In addition, the utilization of various antioxidant compounds, medicinal plants and other compounds for the management of Cd toxicity in testes is discussed.
Objectives:
Complementary feeding should provide a healthy diet with critical nutrients for growth and development. Information is limited on child and infant feeding recommendations within the World Health Organization (WHO) European Region.
Methods:
The WHO Regional Office for Europe and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) performed a survey of national recommendations on infant and young child nutrition aimed at national government departments of health and national paediatric experts. Questions addressed national recommendations on breast-feeding and complementary feeding.
Results:
Information was available from 48 of the 53 Member States. Forty-five of 48 countries (94%) have national recommendations on infant and young child feeding, of which 41 are endorsed by official public health authorities. Regarding introduction of complementary feeding, 25 countries (out of 34, 74%) recommend 6 months of age as the ideal age. The earliest age of introduction recommended varies from 4 to 5 months in (31/38 countries, 82%) to 6 months (6/38, 16%) and 7 months (1/38, 2.6%). The recommended meal composition varies widely; introduction of iron-rich foods (meat, fish, eggs) at the age of 6 months is recommended in 30 out of 43 countries, whereas 13 (30%) recommend later introduction.
Conclusions:
National infant feeding recommendations vary widely between studied countries and partly differ from international recommendations. Too early introduction of complementary feeding can reduce duration of exclusive breast-feeding (EBF). Too late introduction of iron-rich complementary foods might increase anemia risk and adversely affect child development. A review and further harmonization of national recommendations appears desirable.
Entomophagy is increasingly seen as a potential solution to provide more sustainable sources of protein. However, the attitude of Western consumers towards insect-based products is generally negative. This study was designed to evaluate the liking of four insect-based snacks among young Italian consumers through a tasting panel involving 62 participants. Two of the products showed the whole insects, while the other two contained insect flour as a main ingredient. The overall liking of the snacks was quite high, with a mean value of 6.48 on a 1-9 sensory scale; the chocolate bar with insect flour was the most appreciated product (6.95), followed by whole crickets (6.64), chips containing insect flour (6.33), and caramel worms, which scored the lowest (6.02). An ANCOVA model was used to test differences in the overall liking against a set of factors, including the features of the product (sweet/savoury, visible/invisible insect), demographical and behavioural variables and the Food Neophobia Scale (FNS). A general distrust of new foods as well as the willingness to know all ingredients in a food negatively affected the overall liking of the tasted products. The liking was lower for snacks where the whole insect was visible, while no difference was detected in the liking of sweet and savoury products. Although strong cultural barriers still exist, young Italian consumers demonstrated an interest in insect-based products. Further research and communication may help to improve the perception of insects as a food among these consumers.
In our daily life, we are surrounded by harmful pollutants, including heavy metals that are not visible in the macroscopic view easily. Heavy metals can disrupt different aspects of human health, such as the immune system which has gained a lot of attention in recent decades. This had led to its rapid progression and new insights into its alterations in different diseases especially cancer. Heavy metals are non-biodegradable materials that exist in different parts of the food cycle, such as fruits and vegetables as commonly consumed foods and also unexpected sources such as street dust, that exists in the streets that we pass every day, soil, air, and water. These heavy metals can enter the human body through respiratory, cutaneous, and gastrointestinal pathways and then accumulate in different organs, leading to their encountering with various parts of the body. These sources and natural characteristics of heavy metals facilitate their interaction with the immune system. In this review, we investigated the effect of lead and cadmium, as pollutants that exist in many different parts of the human environment, on the immune system which is known to have a key role in the pathophysiology of cancer.
Edible insects seem one of the more probable responses to the increased quantity of food proteins needed in future prospective related to the increase of human population, mainly in developing countries. Introduction of entomophagy in developed countries, especially in Europe and North America, could help this trend and drive the world food economy to reach that goal. Few articles were published on acceptability of edible insect in European countries, with a large variability of methodologies used. Furthermore, both structure and unstructured (or semi-structured) techniques were analysed and compared. Through this review article, we analysed the different methodologies conducted on European consumers and categorised the studies in relation to the type of analysis chosen, data collection and results obtained. Limitation of the research studies and future recommendations were explored leading to better investigate consumers’ acceptance.
Insects are a potential ingredient of food preparations, providing nutrients (e.g. proteins) with a low environmental impact. Despite the benefits, consumers in Western countries generally reject the practice of eating insects. This work aims to measure the intention to and the behaviour of eating novel food products containing insect flour in the next month. The novel food product of choice was a chocolate chip cookie with an ingredient from edible insects (10% of cricket flour), which might be considered as an enriched-in-proteins substitute of traditional cookies. We investigated 231 Italian young adults using the Theory of Planned Behaviour (TPB), assuming that behaviour, given sufficient control, is guided by intention. We used the observation of the actual tasting of the novel food product as a measure of prospective behaviour. The TPB model accounted for 78% of the variance in intention and 19% of the variance in behaviour. Attitude and Perceived Behavioural Control (PBC) are statistically significant predictors of intention, while intentions and PBC are of behaviour. Beliefs that eating an insect-based food product has positive effects on health and the environment significantly affect attitudes and intention. The main barriers preventing the intention of eating food products containing insect flour are the sense of disgust arising from seeing insects around, the incompatibility with local food culture and the lack of products in the supermarket. Interventions may consider targeting behavioural control, developing food products close to the Western dietary pattern, such as bakery products containing insect flour, and signalling the positive effects on health and the environment.
Due to the rapid increase in world population, the waste of food and resources, and non-sustainable food production practices, the use of alternative food sources is currently strongly promoted. In this perspective, insects may represent a valuable alternative to main animal food sources due to their nutritional value and sustainable production. However, edible insects may be perceived as an unappealing food source and are indeed rarely consumed in developed countries. The food safety of edible insects can thus contribute to the process of acceptance of insects as an alternative food source, changing the perception of developed countries regarding entomophagy. In the present study, the levels of organic contaminants (i.e. flame retardants, PCBs, DDT, dioxin compounds, pesticides) and metals (As, Cd, Co, Cr, Cu, Ni, Pb, Sn, Zn) were investigated in composite samples of several species of edible insects (greater wax moth, migratory locust, mealworm beetle, buffalo worm) and four insect-based food items currently commercialized in Belgium. The organic chemical mass fractions were relatively low (PCBs: 27-2065 pg/g ww; OCPs: 46-368 pg/g ww; BFRs: up to 36 pg/g ww; PFRs 783-23800 pg/g ww; dioxin compounds: up to 0.25 pg WHO-TEQ/g ww) and were generally lower than those measured in common animal products. The untargeted screening analysis revealed the presence of vinyltoluene, tributylphosphate (present in 75% of the samples), and pirimiphos-methyl (identified in 50% of the samples). The levels of Cu and Zn in insects were similar to those measured in meat and fish in other studies, whereas As, Co, Cr, Pb, Sn levels were relatively low in all samples (<0.03 mg/kg ww). Our results support the possibility to consume these insect species with no additional hazards in comparison to the more commonly consumed animal products.
The effects of moulting between instars and metamorphosis on the contents of Cd were studied in T. molitor larvae both by following the radioactive tracer 108Cd ingested on one occasion and by analysing Cd concentration in larvae and newly hatched adults with a continuous intake of Cd. Larvae were given 109Cd in one meal. Contents of 109Cd were then determined periodically throughout the larval stage and in newly hatched adults. Moulting lowered the 109Cd contents, but to a smaller degree compared with metamorphosis. The rate of reduction during these processes decreased with time elapsed since ingestion of 109Cd and moulting or metamorphosis. At metamorphosis, the loss of 109Cd took place almost entirely at the pupation. With a continuous intake of Cd, concentrations in T. molitor were correlated to those in their food. Newly hatched adults had lower Cd concentrations than the corresponding larvae, when Cd concentrations in food were high.
Deficiency of several essential nutrients, namely vitamins and essential elements, has been shown to exacerbate the toxic effects of metals, and supplementation of such nutrients ameliorates the toxicity. It is important to evaluate the present levels of metal exposure and the quantities of dietary nutrient supplements that might either augment or protect against the adverse effects of the metals, so that multifaceted components contributing to safety can be incorporated into regulatory decisions. In addition to the role of micronutrients in modifying metal toxicity, these nutritional components (vitamins, essential metals, etc.) can also act as complementary chelating agents (adjuvants) increasing the efficacy of a known chelator, or by acting independently. This article summarizes the major experimental work carried out on the influence of various nutritional factors on metal toxicity and discusses future research.