Grub's up

Fancy a drizzle of fly larvae oil on your rocket salad? Or how about a sprinkling of toasted grasshoppers to top off your breakfast cereal?

Take away the ‘yuck factor’ and there’s no reason why not. Maggot oil is already used in animal feed, and is rich in omega-3 and omega-6 fatty acids, while tiny grasshoppers are packed with nutritious proteins and other micronutrients.

Eating insects is not just a new fad. Around 2bn people already practice ‘entomophagy’, with around 2000 species consumed, says a report from Finnish consultancy Invenire. Current insect consumers, based mainly in Europe and the US, have a ‘deep-seated interest in either insects, sustainability or novelty.’

For his part, entomologist Arnold van Huis from Wageningen University, the Netherlands, is not a great fan of the mealworm but is partial to crickets and grasshoppers. Many insects need good seasoning, but crickets have ‘a taste of their own, which is quite nice, especially if you deep fry them,’ he says.

Insects aren’t just tasty, they are also an increasingly attractive source of protein and micronutrients, he points out. By 2050, the Food and Agriculture Organization (FAO) estimates that global meat demand will have increased by 76%, compared with 2005 levels – putting enormous strain on the available land to grow crops and animal feed.

‘Insects as mini-livestock offer many environmental benefits compared with conventional livestock, while nutritional quality is similar,’ van Huis reflects.¹

Insects are cold-blooded and don’t need to waste energy heating themselves; as a result, they have a high feed conversion efficiency, compared with livestock. Farming insects, instead of pigs, cattle and sheep, uses 50-90% less land per kg protein and 40-80% less feed per kg edible weight, as well as producing significantly lower greenhouse gas emissions, according to a 2014 Wageningen report.²

Protein power

In terms of protein content, insects compare favourably with meat. Locusts and grasshoppers contain 14-18g protein/100g, compared with 19-26 g protein per 100g for raw beef and 16-28g for mackerel. And edible insects are a good source of fat, with oils rich in polyunsaturated fatty acids, and frequently containing essential linoleic (omega-6) and alpha-linolenic (omega-3) acids.

Micronutrients in insects can boost deficient diets, according to a 2013 FAO report on Edible insects: future prospects for food and feed security. The report, which has seen 7m downloads, highlights the case of people in Papua New Guinea with a diet based on tubers, lacking the essential amino acid lysine – a deficiency remedied by eating lysine-rich palm weevil larvae. Edible insects are also good sources of zinc and iron, and so may help to prevent anaemia.

Despite the potential benefits, however, ‘very little has been done on the effects of insect consumption on health effects,’ says Charlotte Payne from the University of Oxford’s Nuffield department of population health in the UK. She points to a study that supplemented the diet of nursing mothers with iron-rich insects, yet saw no decline in levels of anaemia. ‘There may be factors we don’t understand about the bioavailability of nutrients in insects; those kinds of experiments need to be done,’ she adds. There is a possibility that chitin, a fibrous compound in the exoskeleton, may inhibit nutrient adsorption, she suggests.

A 2016 review of nutrient composition data for commercially available insects by Payne and researchers highlighted the nutrient diversity of insects and also the low quality of existing nutritional data.³ Nutrient levels vary between and within species – and also depend on diet. For example, Nigerian grasshoppers fed with bran containing high levels of essential fatty acids have almost double the protein content of those fed on maize.

In a separate study in 2015, the team compared nutrient levels in various insect species by applying Nutrient Value Scores (NVSs) developed by the UN World Food Programme.⁴ Crickets, palm weevil larvae and mealworm were found to have ‘a significantly healthier score’ than beef and chicken.

Meanwhile, interest in edible insect nutrition has grown dramatically in the past couple of years, Payne says, pointing out that over half of 150 papers in the past 15 years were published since 2014. ‘There’s a significant rise in papers on farmed insects and a definite trend towards more industrialised systems.’

Novel foods

In the EU, insect products fall under new novel food regulation, agreed in November 2015. A novel food is one that has not been consumed to any ‘significant degree’ in the EU before May 1997. Novel foods will only be approved for use in the EU after a scientific assessment by the European Food Safety Authority (EFSA). The regulation aims to increase the efficiency of the authorisation procedure, while ‘ensuring a high level of food safety,’ according to the European Commission.

In October 2015, EFSA published a scientific opinion on the viability of insect protein for feed and food.5 ‘The main conclusion was that we need to do more research before we can establish whether insects are safe to eat,’ says co-author Adrian Charlton, head of chemical and biochemical profiling at the UK Food and Environment Research Agency (FERA).

The experts did not find any inherent risks that couldn’t be managed, adds Charlton. The report is clear that the possible presence of biological and chemical hazards in insect-derived food and feed products depends on insect species; production methods; what the insects are fed; the lifecycle stage at which they are harvested; as well as processing methods.

The report points to the possibility of people having allergies to some insect proteins, which are also present in shellfish, including the allergen tropomyosin.

The EFSA panel also addressed the potential issue of abnormal proteins (prions) entering insects from feed. Prions can cause diseases such as BSE in cattle and Creutzfeld-Jakob disease in humans. ‘The risk comes from insects feeding on potentially prion-containing materials, such as spinal cord and brain, or meat that we don’t know the origin of,’ says Charlton. As a result, one of the EFSA recommendations is to feed insects on non-meat materials, such as vegetable waste.

Legislation put in place following the BSE crisis, to prohibit farmers from feeding processed animal protein (PAP) to animals, is now proving to be a major stumbling block for producers hoping to use insects in animal feed. The International Platform of Insects for Food and Feed (IPIFF), founded in 2013, has been lobbying hard to change the regulations, arguing that insect products comply with high EU safety standards.

Currently, over 80% of protein for EU livestock, including soya and corn gluten feed, is imported from non-EU countries. In 2011, the European Parliament adopted a resolution to address the protein deficit, calling for ‘urgent action’ to replace imported protein crops with alternative European sources.

Fly larvae could hold the solution. PROteINSECT (insects as sustainable sources of protein), an EU-funded project involving FERA with partners in Mali, China and Ghana, focuses mainly on two fly species: black soldier fly (H. illucens) and house fly (M. domestica). In China, the project is looking at industrial scale production while researchers in Mali are focusing on individual farmers being able to rear insects for their own livestock. ‘In the UK we are mainly looking at insects for compounding into animal feed,’ says Charlton.

As a tropical/sub-tropical species, the black soldier fly may not be best suited to large scale animal feed production in Europe. However, the house fly can live in a wide range of climates and has a short lifecycle of days, compared with months for crickets, says Charlton. Fly larvae can grow on a ‘zero value waste stream’ and turn it into a ‘very high-value product,’ he says.

Producing fly larvae is relatively simple. One of the advantages of using flies is that they leave their food source when they pupate, crawling over the edge of the substrate trays so they are easily collected.

Charlton leads a PROteINSECT project examining the safety and quality of insects and meat from animals and fish reared on diets containing insect protein. Tests on larvae fed a range of substrates in the UK, China, Mali and Ghana showed the presence of toxic heavy metal cadmium in all samples. ‘What we are doing at the moment is seeing whether that transfers to the meat,’ says Charlton. ‘Early indications are that it is not a huge issue.’

Another PROteINSECT project is processing maggots to extract oil, which can legitimately be sold into the animal feed industry and already has a market in salmon farming. The most straightforward way to extract the oil is to use a solvent, as used by olive oil producers, says Charlton.

Industrial production of insect oil is already increasing. In 2014, Dutch company Protix struck a deal with a feed company called Coppens Animal Nutrition, providing insect lipids to supplement pig and poultry feed. In February 2016, Coppens received the first insect lipid batch.

Protix provides both refined and whole insect lipids from black soldier fly larvae, as well as chitin powders and protein meals. It claims the oil has a high lauric acid content and gives improved chick growth in poultry trials.

Consumer concerns

A PROteINSECT consumer survey suggests 72% of respondents would eat fish, chicken or pork from animals fed insect proteins. Meanwhile, over 50% of consumers think such products should be clearly labelled. ‘If you ask somebody whether they would eat a chicken that had been fed on maggots, they would answer: probably not, says Charlton; however, explaining that up to 30% of the diet of free range hens is naturally insects alters their perception. Big food companies are interested in using insect products but nervous because of a potential consumer backlash, he says.

That notwithstanding, the number of insect-rearing companies is growing, partly for the expanding fish farming market. Fishmeal as feed is becoming scarce, with environmentalists warning that that wild fish populations are being hit. In addition, fly larvae are a better alternative protein source than vegetable-based ingredients, says van Huis.

Agriprotein, a South African company established in 2009, is the main fly larvae producer. Flies are fed on organic waste to produce insect-based protein feed and oil, as well as fertilisers. In 2014, the company set up its first industrial scale facility, producing 800kg of wet larvae/day. The goal is to produce 7t of insect meal, 3t of oil and 20t of fertiliser/day by 2020. In Canada, Enterra Feed Corporation grows black soldier flies on food processing waste, producing protein and oil products for fish farms, as animal feed and pet food. The digestate from the larvae is sold as a natural fertiliser.

While there are big gains to be made in the animal feed industry, consumer perception rules out mass production of insects for human consumption, at least in the short term, says Charlton. When it comes to humans eating insects directly, ‘powdered protein is probably the easiest gateway [for human consumption] because it can be added to products such as bars and ready meals,’ suggests Inverire’s Johanna Tanhuanpää, adding that in her view: ‘Whole insects are never going to be all that mainstream’.

Go online, however, and it’s easy to find insect products ranging from flavoured grasshoppers to whole crickets, cricket powder, chips and protein bars. Or for a gourmet option, Welsh restaurant Grub Kitchen opened its doors in October 2015 and serves up a menu featuring cricket-crepes, bug blinis, and insect burgers made from toasted crickets, mealworms, and grasshoppers.