A joint project with East Africa on the field of global food security
The aim of this project was to improve the livelihood and nutritional situation in urban and peri-urban areas in Kenia and adjacent areas in Tanzania and Ethiopia. The main focus lied on increasing production and supply of indigenous African vegetables and to improve efficiency of the respective value chain.
In 14 subprojects knowledge to increase productivity, product quality, shelf life, processing, logistic, and marketing was developed.
Research activities of the Department of Safety and Quality of Fruit and Vegetables were located in subprojects four and five. Quality losses in the value chain as well as a short shelf-life of African leafy vegetables are serious problems in Africa. Therefore, firstly possible quality losses were identified in subproject four. Followed by measurements to improve the quality and safety of African leafy vegetables and to prolong the shelf-life. Influences of modified atmosphere storage, post-harvest processing methods like fermentation, and solar drying on the quality (ingredients and microbiological quality) and safety (pathogens and mycotoxins) of the vegetables were investigated. The required plant material was cultivated in the phytotron and greenhouse of the Department of Safety and Quality of Fruit and Vegetables.
The post-harvest technology of fermentation using selected lactic acid bacterial starter cultures had a positive effect on the vitamin E content of the investigated African leafy vegetables, whereas significant losses of vitamin C, B1 and B2 were observed. In contrast, solar drying showed a positive effect on the preservation of vitamins E, B1 and B2, but not on the preservation of vitamin C. Controlled fermentation improved the safety of the fermented product by quickly lowering the pH-value and inhibiting pathogenic bacteria such as Listeria monocytogenes and Salmonella Enteritidis. The basic nutrients did not change significantly during fermentation. Minor changes were only observed for proteins, dietary fibres, and sucrose. Fermentation of African leafy vegetables with selected lactic acid bacterial starter cultures thus proved to be a very good method to produce a safe fermented food, and to avoid post-harvest losses.
HORTINLEA (Horticultural Innovations and Learning for Improved Nutrition and Livelihood in East Africa) was one of six projects funded by the BMBF in the frame of “GlobE: Global food security of the national research strategy BioÖkonomie 2030”. The joint project with a funding time from 2013 to 2018 was elected out of 50 applications and funded with 1.5 Mill. Euro per year. The project was co-ordinated by the Humboldt Universität zu Berlin, Prof. Dr. Bokelmann.
Financed by the Federal Ministry of Education and Research.
Co-financed by the Federal Ministry for Economic Cooperation and Development.
Stoll DA, Wafula, E.N., Mathara, J.M., Trierweiler, B., Kulling, S.E., Huch, M.: Fermentation of African nightshade leaves with lactic acid bacterial starter cultures. International Journal of Food Microbiology 342, 2021, doi: 10.1016/j.ijfoodmicro.2021.109056
Gogo EO, Trierweiler B, Opiyo AM, Frommherz L, Frechen M, Ulrichs C, Huyskens-Keil S: Reducing postharvest losses using modified atmosphere packaging bags for African nightshade (Solanum scabrum Mill.) leaves. Acta Horticulturae (1205), 97-108, 2018, doi: 10.17660/ActaHortic.2018.1205.11
Eliud Nalianya Wafula, Doctorate Thesis entitled ‘Effects of Postharvest-Processing Technologies on the Safety and Quality of African Indigenous Leafy Vegetables’. Faculty of Mathematics, Informatics and Natural Sciences, in the Department of Chemistry, University of Hamburg, 2017.