Attempts to preserve food are as old as mankind itself – already thousands of years ago humans applied techniques to increase the shelf life of foodstuff and therefore be able to store it for times of scarcity. However, not every conservation technique is easily adaptable to any context worldwide and sometimes it requires alternative ideas to make time-tested technologies suitable for a new context. One of these adaptations is currently successfully being tested in the Ethiopian highlands; the heat of the sun is employed to process raw food materials and thus preserve them over time.
The preservation of fresh foodstuff through boiling and canning has a long-standing tradition in many European countries. Particularly in earlier generations, this technique was utilized to make sure that seasonally available food products were also accessible during the winter. Especially in rural areas, locally harvested fruits and vegetables used to be preserved for later consumption through prolonged cooking. Although a certain amount of micronutrients gets lost during the process due to the effect of heat, the final product provides a valuable source to ensure an adequate and balanced diet over the course of the year.
While in Germany the cold months of the winter season obliged people to plan ahead and store food products, the dry season in the Ethiopian highlands brings about a similar effect; locally harvested fruits and vegetables, especially fresh tomatoes and mangos, have a very limited shelf life unless processed properly. After the harvest, farmers are therefore forced to consume or sell their products rapidly. As a consequence, the supply of foodstuff is excessive during the harvesting season, market prices collapse drastically and comestibles perish, whereas food is urgently needed during the dry season.
The lack of methods of food preservation constitutes a serious problem on the entire African continent and causes the perishing of almost 40 percent of the produced foodstuff before it even gets to the consumer.1 At the same time, in the Ethiopian highland region of Tigray alone 47 percent of children under the age of 5 are affected by chronic undernutrition (stunting).2
The project ‚Nutrition Sensitive Agriculture‘, which is carried out by the GIZ within the framework of the German ‘One World – No Hunger’-initiative, aims at improving the nutrition situation of food-insecure people in various districts of Tigray.
The year-round availability of balanced and quantitatively sufficient foodstuff, even in the dry season, constitutes a key element of food security. Successful preservation techniques for locally produced, agricultural products are capable of significantly contributing to this goal.
In order to transfer the methodology of boiling food for preservation purposes to the context of the Ethiopian highlands, it is, however, necessary to overcome a fundamental problem first; 98 percent of rural households in the eastern African country do not have electricity. Yet the prolonged heating necessary to preserve the fresh food and thereby make it storable requires a considerable amount of energy.
While the local population usually resolves this problem through the ecologically unsustainable use of fire woods, the project reverts to a natural source of abundant energy which is both free of charge and side effects: the sun. Solar energy is captured through solar-powered stoves and the thereby generated heat is used to transform fresh foodstuff into tomato paste, ketchup, mango concentrate, juice, jam, honey or sauerkraut, but also to process dairy products to fabricate butter and cheese.
No less innovative but equally independent of electricity is the manual compression of oil, which also helps towards securing an adequate and diversified nutrition in the target region. With the help of hand-operated oil mills which are currently being distributed in the region, locally grown sesame-, sun flower- and linseeds are processed into oils which are to be consumed locally. That way, local farmers do not have to rely on imported, nutrient-poor products such as palm oil anymore but can instead fabricate high-quality products with local inputs themselves.