Entomophagie et risque allergique

Allergens from Edible Insects: Cross-reactivity and Effects of Processing

PURPOSE OF REVIEW

The recent introduction of edible insects in Western countries has raised concerns about their safety in terms of allergenic reactions. The characterization of insect allergens, the sensitization and cross-reactivity mechanisms, and the effects of food processing represent crucial information for risk assessment.

RECENT FINDINGS

Allergic reactions to different insects and cross-reactivity with crustacean and inhalant allergens have been described, with the identification of new IgE-binding proteins besides well-known pan-allergens. Depending on the route of sensitization, different potential allergens seem to be involved. Food processing may affect the solubility and the immunoreactivity of insect allergens, with results depending on species and type of proteins. Chemical/enzymatic hydrolysis, in some cases, abolishes immunoreactivity. More studies based on subjects with a confirmed insect allergy are necessary to identify major and minor allergens and the role of the route of sensitization. The effects of processing need to be further investigated to assess the risk associated with the ingestion of insect-containing food products.

Novel Foods and Sustainability as Means to Counteract Malnutrition in Madagascar

Although the trends of international reports show an increase in overweight and obesity, even in developing countries, there are still areas of the world, such as Sub-Saharan Africa, strongly affected by undernutrition. Specifically, in Madagascar, the percentage of stunted children under 5 is extremely high. Furthermore, the COVID-19 pandemic is expected to increase the risk of all forms of malnutrition, especially in low-income countries, including Madagascar, with serious intergenerational repercussions. This narrative review aims at investigating eating habits and cooking methods of the Malagasy population, addressing sustainable healthy diets through promotion of novel foods. While novel foods are a recent concept, there are data that describe how they may contribute to counteract food insecurity and malnutrition considering context and place. Efforts to promote native, traditional foods as Moringa oleifera, an indigenous plant in Asia and Africa including Madagascar, rich in protein and micronutrients, as well as edible insects, alternative sustainable source of protein, lipids, iron, and zinc, would provide not only nutritional but also cultural and economic benefits. The potential synergies between food traditions and agroecology have the potential to impact health addressing larger issues of sustainability and food security. Regional, national, and international policies are needed to develop and support one health approach actions.

A Proteomic- and Bioinformatic-Based Identification of Specific Allergens from Edible Insects: Probes for Future Detection as Food Ingredients

The increasing development of edible insect flours as alternative sources of proteins added to food and feed products for improving their nutritional value, necessitates an accurate evaluation of their possible adverse side-effects, especially for individuals suffering from food allergies. Using a proteomic- and bioinformatic-based approach, the diversity of proteins occurring in currently consumed edible insects such as silkworm (Bombyx mori), cricket (Acheta domesticus), African migratory locust (Locusta migratoria), yellow mealworm (Tenebrio molitor), red palm weevil (Rhynchophorus ferrugineus), and giant milworm beetle (Zophobas atratus), was investigated. Most of them consist of phylogenetically-related protein allergens widely distributed in the different groups of arthropods (mites, insects, crustaceans) and mollusks. However, a few proteins belonging to discrete protein families including the chemosensory protein, hexamerin, and the odorant-binding protein, emerged as proteins highly specific for edible insects. To a lesser extent, other proteins such as apolipophorin III, the larval cuticle protein, and the receptor for activated protein kinase, also exhibited a rather good specificity for edible insects. These proteins, that are apparently missing or much less represented in other groups of arthropods, mollusks and nematods, share well conserved amino acid sequences and very similar three-dimensional structures. Owing to their ability to trigger allergic responses in sensitized people, they should be used as probes for the specific detection of insect proteins as food ingredients in various food products and thus, to assess their food safety, especially for people allergic to edible insects.

High Hydrostatic Pressure-Assisted Enzymatic Hydrolysis Affect Mealworm Allergenic Proteins

Edible insects have garnered increased interest as alternative protein sources due to the world's growing population. However, the allergenicity of specific insect proteins is a major concern for both industry and consumers. This preliminary study investigated the capacity of high hydrostatic pressure (HHP) coupled to enzymatic hydrolysis by Alcalase^® or pepsin in order to improve the in vitro digestion of mealworm proteins, specifically allergenic proteins. Pressurization was applied as pretreatment before in vitro digestion or, simultaneously, during hydrolysis. The degree of hydrolysis was compared between the different treatments and a mass spectrometry-based proteomic method was used to determine the efficiency of allergenic protein hydrolysis. Only the Alcalase^® hydrolysis under pressure improved the degree of hydrolysis of mealworm proteins. Moreover, the in vitro digestion of the main allergenic proteins was increased by pressurization conditions that were specifically coupled to pepsin hydrolysis. Consequently, HHP-assisted enzymatic hydrolysis represents an alternative strategy to conventional hydrolysis for generating a large amount of peptide originating from allergenic mealworm proteins, and for lowering their immunoreactivity, for food, nutraceutical, and pharmaceutical applications.

Insights into the Allergenic Potential of the Edible Yellow Mealworm (Tenebrio molitor)

The edible yellow mealworm (Tenebrio molitor), contains an extremely diverse panel of soluble proteins, including proteins with structural functions such as muscle proteins, as well as proteins involved in metabolic functions such as enzymes. Most of these proteins display a more or less pronounced allergenic character toward previously sensitized people, especially people allergic to shrimps and other shellfish. A mass spectrometry approach following the separation of a mealworm protein, extracted by sodiumdodecyl sulfate-polyacrylamide gel electrophoresis, allowed us to identify up to 106 distinct protein fractions including molecules with structural and functional functions, susceptible to developing an allergenic potential due to the possibility of immunoglobulin E-binding cross-reactions with their counterparts occurring in shellfish. In this respect, most of the sera from people allergic to shrimps reacted with the mealworm protein extract in Western blot experiments. Moreover, the potential mealworm allergens triggered the in vitro degranulation of rat leukemic basophils transfected with the human high-affinity IgE receptor (FcεRI), upon sensitization by the IgE-containing sera from people allergic to shrimps and other shellfish foods. Owing to the large repertoire of IgE-binding cross-reacting allergens the yellow mealworm shares with other phylogenetically-related groups of arthropods, it would seem prudent to inform the consumers, especially those allergic to shellfish, by appropriate labeling on edible mealworm packages about the potential risk of developing an allergic reaction.

Limited cross reactivity among arginine kinase allergens from mealworm and cricket edible insects

Insects are seen as a solution to the increasing demand for protein sources for food. However, entomophagy has unfortunately been linked to allergic reactions in Europe with people with professional contacts. As mealworms (Tenebrio molitor) and crickets (Acheta domesticus) have recently become commercially available (both whole or in food formulation) in several European countries, this research assessed the cross allergenicity of arginine kinase (AK). Based on the collection of sera from a entomology laboratory staff, oven cooked insects but also purified AK fractions were tested. Immunoblotting against the protein extracts revealed different Immunoglobulin E reactivity of sera according to the insect target species: two bands (40 and 14 kDa) for crickets and a pattern including light responses at 17, 25 and 37 kDa for mealworms. Focusing on AK, low specific allergenicity was here illustrated and discussed in relation to the development of a safe edible insect consumption by humans.

Ugly but tasty: A systematic review of possible human and animal health risks related to entomophagy

BACKGROUND

According to many recent studies, the use of insects as food seems to be convenient, sustainable, economical and healthy. The objective of this study is to analyze the possible effects of insect consumption on human and animal health.

METHODS

A systematic review of the literature was performed using the PubMed, Scopus and CAB databases.

RESULTS

Of the 6026 items initially retrieved, 70 were eligible for inclusion; 40 studies analyzed the use of insects in human foods or drugs, while 30 analyzed the use of insects in animal feed. In humans, the most commonly analyzed risks are nutrient malabsorption, growth alteration, chemical and microbiological contamination and allergy risk. Studies of animals focus on growth alteration, nutrient malabsorption and hematic and qualitative meat alteration.

CONCLUSION

In recent years, researchers have shifted their focus from the possible use of edible insects in animal feed to their use as possible nutrient sources for humans. The results suggest that, if properly treated and preserved, products derived from insects are safe and efficient sources of nutrients for animals. Further studies are needed to evaluate the possible effects of prolonged insect consumption on human health.

Traditions, beliefs and indigenous technologies in connection with the edible longhorn grasshopper Ruspolia differens (Serville 1838) in Tanzania

BACKGROUND

Edible insects are an important source of food to many African populations. The longhorn grasshopper, Ruspolia differens (Serville 1838), commonly known as senene in Tanzania is one of the most appreciated edible insects by societies around Lake Victoria crescent. Senene is primarily an essential treat for the tribes around the lake, e.g., the Haya of Tanzania, Luo of Kenya and Baganda of Uganda. Despite its importance as a food item and appreciation as a delicacy, there are few studies dealing with culture, beliefs and indigenous technology in connection with the senene. The main objective of this study was to survey indigenous technologies, processing methods and traditions in relation to senene consumption among the Haya tribe in Kagera region of Tanzania.

METHODS

Our ethnographic study was conducted through semi-structured interviews. A total of 51 locals, 26 females and 25 males aged 21 to 60 years were interviewed (with 3 female and 7 male key informants among them). Questions focused on cultures, beliefs and traditions towards senene consumption. Processing, preservation and shelf-life as well as nutritional knowledge were also investigated.

RESULTS

Harvesting for household consumption was mainly done through wild collection. Traditionally made traps were mostly used for commercial harvesting. Deep frying was the most preferred processing method while smoking was the most preferred preservation method, with shelf-life of up to 12 months. Interesting traditions and taboos associated with senene consumption were identified, with men monopolising the insects as food by declaring the insects taboo for women and children. Deep fried senene in locally packed containers were mostly sold by street vendors, but also available from a variety of stores and supermarkets.

CONCLUSION

Beyond being just an important traditional delicacy, senene is becoming increasingly popular, providing opportunity for local businesses. Indigenous technologies for harvesting, processing and preserving senene exist, but must be improved to meet food processing standards, thereby promoting commercialization. This carries economic potential essential for improving incomes and livelihoods of women and smallholder farmers, improving household level food security.

Review of Black Soldier Fly (Hermetia illucens) as Animal Feed and Human Food

Food futurists accept that sustainability-minded humanity will increasingly incorporate insects as alternative protein. The most studied and easily reared species are not necessarily the most sustainable, acceptable, or delicious. Here, we review the literature on the black soldier fly, Hermetia illucens, which is capable of efficiently converting a wide variety of organic materials, from food waste to manure, into insect biomass. They can be grown and harvested without dedicated facilities and are not pestiferous. Their larvae are 42% crude protein and 29% fat, although they are higher in saturated fats than most insects. They do not concentrate pesticides or mycotoxins. They are already grown and recommended for use as animal feed, but with regional legal restrictions on how this is done. For commercial use in human foods, larvae could potentially be milled and converted into a textured protein with a strong flavor. Their biggest advantage over other insects is their ability to convert waste into food, generating value and closing nutrient loops as they reduce pollution and costs. This general advantage is also their greatest disadvantage, for the social stigmas and legal prohibitions against eating organisms that eat waste are added to extant taboos facing insect consumption.