20 Apr Edible insects: a neglected resource for food security in Africa
Christopher Mutungi, Postharvest Specialist, IITA-Tanzania; Francis Irungu, PhD candidate Egerton University; Komi Fiaboe,– Entomologist, IITA; Abass Adebayo, Postharvest specialist, IITA
Insects are part of the diet for humans and domesticated animals in many African cultures. Insect farming has great potential to contribute to food security by increasing the essential nutrients–protein and micronutrients–in human and livestock diets. To this end, IITA scientists and partners reviewed sand consolidated available evidence of postharvest technologies for edible insects in Africa (https://cgspace.cgiar.org/handle/10568/93015), identifying new research areas that can enhance the access to and consumption of edible insects as a resource for increasing food security and nutrient quality.
Africa: a hotspot for edible insect biodiversity
Over 500 insect species are eaten by humans or used to feed animals in 34 African countries. The Central African region uses the highest number of insect species (256) followed by Southern (164), Eastern (100), and West Africa (91). At least 13 countries consume more than 20 insect species. The insects include caterpillars of butterfly and moth (30%), grasshoppers, locusts and crickets (29%), beetles (19%), and others such as termites, wasps, bees, ants, bugs, and flies (22%).
Insects as source of food and revenue
There is abundant evidence on the role of insects in the human diet and the economic conditions of communities. Fresh, fried, smoked, roasted, and dried insects are found in village markets and favorite species reach urban markets and restaurants. The consumption of insects helps in closing the gap in total protein intake in many communities. Insect consumption is seasonal and could be significantly high during the lean periods including before crop harvest, serving as food insurance and a source of revenue in many rural areas. In Uganda, grasshoppers contribute about 500 g of protein in diets of consuming individuals annually. In the DRC, caterpillars constitute 40% of the total animal protein consumption of the population. It was estimated that the average household in Kinshasa consumed 300 g of caterpillars each year, translating to 96 metric tons of caterpillars consumed in the city in the 1990s.
Among the Gbaya people of Central African Republic, insect consumption accounts for 15% of the protein intake, while 95% of the population that lives in the forest zones was reported to depend on insects to meet their protein, fat, and micronutrient needs. In Zambia, caterpillars are the single most important source of nutrients during the lean season and constitute 40% of the specialties consumed by the Lala tribe during this period. In Zimbabwe, 90% of the population consumed insects and the practice contributed significantly to the prevention of protein malnutrition and kwashiorkor among the children of poor rural communities.
In terms of revenue generation, edible grasshoppers and moth caterpillars are sold at higher prices than beef in Uganda and Nigeria. The income from moth caterpillars in Botswana was estimated to be approximately 13% of total annual household revenue at the turn of the century. Cross-border trades in edible mopane worms was reported to employ over 30,000 people every season across Zambia, Botswana and South Africa, contributing about US$85 million in annual sales. Thus, grasshoppers, termites, crickets, palm weevils, and other insects that are consumed across Africa every year represent an enormous overall trade value.
Improving processing and packaging
Traditionaly, the harvested insects are processed by smoking, brining, frying, steaming, boiling, roasting, toasting, and drying, and are packaged in tins, plastic containers, baskets, or sacks. For safety reasons and the need for retention of the nutritional composition of processed insects, these indigenous processes require optimization. There is ample evidence that during the indigenous processing practices, the insects may accumulate biological or chemical contaminants that are potentially hazardous and anti-nutritive.
Recent research on effective insect processing and packaging aim to minimize food hazards and increase shelf life (https://doi.org/10.1016/j.foodres.2018.01.012). There are indications that better hazard control and product upgrade or standardization can be achieved if indigenous processing practices are supported with quality assurance mechanisms by applying hygiene and safety management tools such as Good Manufacturing Practices (GMP) and Hazard Analysis Critical Control Point (HACCP). Further research is required to establish alternative processing techniques at the commercial level.
Developing new food and feed products
To derive benefits from edible insects on a large scale, new technologies for intensive insect rearing to replace harvesting from the wild require special attention. Nonetheless, some insect species are already being mass-produced in some parts of the world. The black soldier fly is farmed for animal feed whereas crickets, mealworms, silkworms, grasshoppers, and locusts are farmed for human or pet food. This selection is based on ease of mass production, nutritional content, and environmental implications.
There are prospects in developing new insect-based products such as nutrient-fortified food and feeds, and extracted products. Opportunities also exist for small farmers to process intermediate products such as dried powders which can be delivered to food and feed factories as raw material for manufacturing value-added industrial products. Already, insect farming initiatives have taken off in Africa.
However, cost-effective mass-rearing techniques that provide consistent quantities need to be developed, and more value-addition options established.
The use of insects in the animal feed sector has received attention recently due to the rising cost of protein sources for feed formulation. In many African countries, poultry and fish enterprises are among the fastest growing agribusinesses. But the cost of feed is prohibitive, representing 60-70% of total production costs. Insects are natural feed for fish and poultry. Some ground-breaking research on the inclusion of insect meal for the manufacture of extruded fish feeds was accomplished https://cgspace.cgiar.org/handle/10568/92542?show=full.
To increase consumption of edible insects beyond the traditional areas, some sociocultural issues need to be addressed. Negative perceptions about insect consumption which is dominant among people and cultures that traditionally do not consume them need to be overcome. The lack of legislative and regulatory frameworks to promote insect-use keeps the insect sector in a state of perpetual dormancy. Also, the lack of quality and safety standards and the absence of guidelines for handling other associated potential risks of insect collection and rearing is partly due to knowledge gaps. It is expected that these challenges will be overcome as more research data becomes available.
These highlights are expounded in a review article published in Critical Reviews in Food Science and Nutrition https://doi.org/10.1080/10408398.2017.1365330.
The work was accomplished through funding by IDRC/ACIAR Cultiaf grant No. 107839-001 to icipe