This article is an edited excerpt from the Regional Strategic Analysis and Knowledge Support System (ReSAKSS) Annual Trend and Outlook Report 2022..
Interest in traditional African vegetables – including spider plant, amaranth, African nightshade, African eggplant, jute mallow, cowpea leaves, narrow leaf, sweet potato leaves and squash – is increasing, particularly among wealthier urban consumers.
Kenya and Tanzania are uniquely positioned to benefit from the domestic and regional markets that are expanding through their ports and central locations. There is great potential to increase the production and processing of these crops in Kenya and Tanzania, which could improve the utilization of vegetable processing units. More than 90% of agricultural products in the two countries are sold unprocessed. The value added in traditional African vegetables goes largely untapped, although it’s important to remember that, from a nutritional perspective, they’re best eaten fresh with minimal processing.
In Tanzania, amaranth and sweet potato leaves are the most popular, while in Kenya, cowpea and African nightshade leaves are the most popular. Both resilient and nutritious, this vegetable is attracting a lot of interest from health-conscious urban consumers. Traditional African vegetables also have the potential to improve environmental sustainability by contributing to agrobiodiversity and increasing farmers’ climate resilience. They are generally better adapted to local growing conditions and require fewer external inputs than exotic fruits and vegetables such as pineapples and tomatoes, which are typically grown in monocultures. However, the production of traditional African vegetables can be highly seasonal and market prices fluctuate widely.
Processing can reduce such price fluctuations while increasing overall supply and creating value for smallholders and traders. The processing of traditional African vegetables has a tradition in East Africa, but the proportion that is currently processed is small. It is estimated that 2.1% of Kenyan farmers and 14.5% of middlemen process these crops. Basic processing by farmers and traders includes washing, plucking the leaves from the stalks (stems), chopping, grading and grading, and blanching. Over 88% of consumers in Kenya are willing to pay more for cleaned, sorted and graded fresh cowpea leaves, while 35% and 25% of consumers respectively prefer de-stemmed and chopped vegetables to unprocessed vegetables. Sun drying under the open sky is also common throughout sub-Saharan Africa, as is drying in the shade with passive or active air circulation. More recently, solar dryers have been introduced to dry vegetables more efficiently and consistently than shade drying.
More advanced processing methods can include refrigeration, fermenting, freezing, and processing into vegetable powder. Refrigeration and refrigeration are currently only used in supermarket value chains. Fermentation using lactic acid is practiced on a small scale, but there are health concerns if not done properly. When freezing, the vegetables are blanched and vacuum packed in polyethylene bags. There is also a tradition in Kenya and Tanzania of using vegetable powder to prepare soups or stews (e.g. as a bouillon) or to enrich corn or millet flour. The use of vegetable powder with sesame seeds (Simsim) to make healthy snacks has been documented in Kenya, including Simshade (a mixture of nightshade and sesame), Simco (cowpea and sesame) and Simama (amaranth and sesame) snacks. Such processed snacks are still being tested and are not yet widely available, although there is evidence that more affluent urban consumers are willing to pay for such products. Ingredients that only slightly affect taste and appearance are rated more positively than those that change food more.
African leafy greens are often considered poor man’s food: people generally prefer starchy staples, meat and imported vegetables, resulting in low consumer awareness of the nutritional and health benefits of local leafy greens. This perception has changed among more affluent urban consumers, but consumption of African leafy greens nonetheless remains low. Although there is great potential for processing this vegetable, currently processing remains largely small-scale and artisanal. The link between producers and consumers is not organized, prices are volatile and compliance with food safety standards is low. Some processing options have low consumer acceptance; For example, a study in Kenya showed that 44% of consumers were unwilling to pay for frozen cowpea leaves and 70% were uninterested in frozen vegetables in general, indicating the need to create awareness of the nutritional value of frozen vegetables .
Government policy goals in Kenya and Tanzania are aimed at ensuring that all citizens receive an adequate, varied and healthy diet through improved storage and processing of food, including vegetables. However, research efforts, advisory services, policies and subsidies largely ignore traditional African vegetables and mainly target staple crops and foods and vegetables destined for export.