Birgit A. Rumpold

Nutritional composition and safety aspects of edible insects

Insects, a traditional food in many parts of the world, are highly nutritious and especially rich in proteins and thus represent a potential food and protein source. A compilation of 236 nutrient compositions in addition to amino acid spectra and fatty acid compositions as well as mineral and vitamin contents of various edible insects as derived from literature is given and the risks and benefits of entomophagy are discussed. Although the data were subject to a large variation, it could be concluded that many edible insects provide satisfactorily with energy and protein, meet amino acid requirements for humans, are high in MUFA and/or PUFA, and rich in several micronutrients such as copper, iron, magnesium, manganese, phosphorous, selenium, and zinc as well as riboflavin, pantothenic acid, biotin, and in some cases folic acid. Liabilities of entomophagy include the possible content of allergenic and toxic substances as well as antinutrients and the presence of pathogens. More data are required for a thorough assessment of the nutritional potential of edible insects and proper processing and decontamination methods have to be developed to ensure food safety.

Recovery and techno-functionality of flours and proteins from two edible insect species: Meal worm (Tenebrio molitor) and black soldier fly (Hermetia illucens) larvae

Depending on the species, edible insects are highly nutritious and thus represent a noteworthy alternative food and feed source. The current work investigates the protein extractability and techno-functionality of insect flour fractions recovered from Tenebrio molitor and Hermetia illucens. T. molitor and H. illucens flours contained about 20% crude fat and 60% and 36 % crude protein, respectively. Defatting reduced the crude fat content to 2.8% (T. molitor) and 8.8% (H. illucens) and increased the crude protein content to 68% and 47%, respectively. To isolate proteins from the flours, protein solubility was optimized by varying the pH, the ionic strength, and the extraction temperature of the solvent. All products and by-products accumulated in the protein production process were characterized by composition, selected techno-functional properties, protein solubility, composition and structure as well as their microbial load.

Safety aspects of the production of foods and food ingredients from insects

At present, insects are rarely used by the European food industry, but they are a subject of growing interest as an alternative source of raw materials. The risks associated with the use of insects in the production of foods and food ingredients have not been sufficiently investigated. There is a lack of scientifically based knowledge of insect processing to ensure food safety, especially when these processes are carried out on an industrial scale. This review focuses on the safety aspects that need to be considered regarding the fractionation of insects for the production of foods and food ingredients.

Insect biodiversity: underutilized bioresource for sustainable applications in life sciences

Due to the growing world population and changing eating habits, there is an increasing demand in sustainable alternative protein sources, whereas the available land for the production of plant and animal protein decreases owing to desertification and urbanization. Furthermore, the rapidly decreasing resources of fossil fuels necessitate more sustainable production cycles combined with well-conceived land use. This includes the establishment of novel utilization pathways for hitherto not or insufficiently used biomass. In this context, insects offer prospective alternatives, since they represent highly efficient and, due to evolutionary processes, highly optimized bioreactors that have the ability to effectively and autonomously convert biomass into biochemical compounds such as proteins, fat, and chitin by combined mechanical, chemical, and microbiological degradation. Furthermore, insects are a vastly underutilized bioresource and need to be exploited for the bioconversion and valorization also of hitherto not usable organic residues to food, feed, chemicals, enzymes, and other bioactive compounds. Mentionable is here also the production of attractants, repellants, defensive, and other chemicals such as antimicrobial peptides that open up new opportunities for therapeutical and biotechnological applications, for example regarding plant pest management.

Nutrient composition of insects and their potential application in food and feed in Europe

With the increasing demand for alternative protein sources for food and feed due to a growing global population and changing food habits, insects and insect proteins have attracted attention in Europe as a hitherto unexploited alternative animal protein source for food and feed. The nutrient compositions, amino acid spectra, and mineral compositions of the three exemplary insect species Acheta domesticus (adult house crickets), Tenebrio molitor (mealworm larvae), and Hermetia illucens (black soldier fly larvae) are compared with the two conventional feed components soy bean meal and fish meal as well as with the human amino acid requirement, and the potential and suitability of edible insects as food and feed is discussed.

Utilization of organic residues using heterotrophic microalgae and insects

Various organic residues occur globally in the form of straw, wood, green biomass, food waste, feces, manure etc. Other utilization strategies apart from anaerobic digestion, composting and incineration are needed to make use of the whole potential of organic residues as sources of various value added compounds. This review compares the cultivation of heterotrophic microalgae and insects using organic residues as nutrient sources and illuminates their potential with regard to biomass production, productivity and yield, and utilization strategies of produced biomasses. Furthermore, cultivation processes as well as advantages and disadvantages of utilization processes are identified and discussed. It was shown that both heterotrophic algae and insects are able to reduce a sufficient amount of organic residues by converting it into biomass. The biomass composition of both organisms is similar which allows similar utilization strategies in food and feed, chemicals and materials productions. Even though insect is the more complex organism, biomass production can be carried out using simple equipment without sterilization and hydrolysis of organic residues. Contrarily, heterotrophic microalgae require a pretreatment of organic residues in form of sterilization and in most cases hydrolysis. Interestingly, the volumetric productivity of insect biomass exceeds the productivity of algal biomass. Despite legal restrictions, it is expected that microalgae and insects will find application as alternative food and feed sources in the future.

Consumer acceptance of foods containing edible insects in Belgium two years after their introduction to the market

As the Belgian market and legislation on insect-based foods have evolved the past years, this study aimed at generating an updated and representative insight into the consumer acceptance of these foods. Data were collected via a telephone survey. The distribution of the 388 respondents across regions, gender and age matched that of the Belgian population. Of those surveyed, 79% were aware of the fact that foods with insects can be bought; 11.2% had already eaten foods with processed insects; 31.8% had no experience but were willing to try, and 57% had no experience or interest in tasting such products. Potential consumers accepted invisible processed mealworms in energy shakes (60.7%), energy bars (59.6%), burgers (59.3%), soup (56.8%), sandwich spreads (56.2%), unfried snacks (56.2%) and fried snacks (52.7%). Consumers indicated that the presence of insects should be clearly declared on the package and that they wanted to be able to buy these products primarily in the supermarket.

Screening of microbial communities associated with endive lettuce during postharvest processing on industrial scale

In this study, the composition of the microbial community on endive lettuce (Cichorium endivia) was evaluated during different postharvest processing steps. Microbial community structure was characterized by culture-dependent and culture-independent methods. Endive lettuce was sampled exemplarily at four different stages of processing (raw material, cut endive lettuce, washed endive lettuce, and spin-dried (ready to pack) endive lettuce) and analysed by plate count analysis using non-selective and selective agar plates with subsequent identification of bacteria colonies by matrix-assisted laser desorption/ionization time-of light mass spectrometry (MALDI-TOF MS). Additionally, terminal-restriction fragment length polymorphism (TRFLP) analysis and 16S rRNA gene nucleotide sequence analysis were conducted. The results revealed structural differences in the lettuce microbiomes during the different processing steps. The most predominant bacteria on endive lettuce were detected by almost all methods. Bacterial species belonging to the families Pseudomonadaceae, Enterobacteriaceae, Xanthomonadaceae, and Moraxellaceae were detected in most of the examined samples including some unexpected potentially human pathogenic bacteria, especially those with the potential to build resistance to antibiotics (e.g., Stenotrophomonas maltophilia (0.9 % in cut sample, 0.4 % in spin-dried sample), Acinetobacter sp. (0.6 % in raw material, 0.9 % in cut sample, 0.9 % in washed sample, 0.4 % in spin-dried sample), Morganella morganii (0.2 % in cut sample, 3 % in washed sample)) revealing the potential health risk for consumers. However, more seldom occurring bacterial species were detected in varying range by the different methods. In conclusion, the applied methods allow the determination of the microbiomes structure and its dynamic changes during postharvest processing in detail. Such a combined approach enables the implementation of tailored control strategies including hygienic design, innovative decontamination techniques, and appropriate storage conditions for improved product safety.