Enhancing essential oil feedstocks and high-value products from Mentha species for local Ugandan economies.

Several aromatic oil compounds (essential oils) of high commercial value are produced naturally by the leaves of mint plants (Mentha). Mint oil extracts are promoted for their health benefits and are used to flavour drinks, ice cream, chewing gum, as well as in cosmetics and personal care products such as toothpaste and shower gel. Menthol is a key component of mint essential oils, particularly those isolated from peppermint Mentha x piperita, and has a large international market with a value of around $800m p.a. Another chemical component, nepetalactone, a potent natural insect repellent normally found in catnip, has recently been identified in the pineapple mint species Mentha suaveolens. As part of a previous collaborative project, the potential for mint as a non-food crop for Ugandan farmers has been explored, a mint garden with selected varieties established near Kampala, and pilot-scale distillation equipment constructed to extract oil from a harvested spearmint crop. This suggests that wide-scale commercial cultivation of mint crops in Uganda could represent a viable resource for globally competitive production of mint essential oils. This project aims to develop novel mint varieties for cultivation in Uganda to produce high yields of essential oils containing menthol or nepetalactone which will be used to develop locally-produced products for the benefit of the rural Ugandan economy.
This application, involving partnerships between Cardiff (Wales) and Makerere (Uganda) Universities, seeks to maximise the production of selected essential oils using two parallel strategies. Firstly, we will screen a range of mint varieties to identify those with naturally high yields of menthol or nepetalactone using biochemical analysis (chromatography) of extracted oils, and those with the largest abundance of oil-bearing glandular leaf hairs (trichomes) by microscopic analysis of the leaf surface. The second strategy will be to manipulate key genes involved in the biosynthesis of essential oils in the leaf, with the aim of creating new 'elite' mint varieties by up-regulating the production of menthol. Such genetic modifications are feasible, due to recent advances in scientific understanding of the biochemical pathway leading to menthol production in mint oil. The most promising mint varieties will be selected for subsequent field trials to determine their viability for growth under potentially conditions of water availability, shading and soil type, in three regions of Uganda.
Together with our partners in Uganda, we will create local Community Enterprise (CE) groups to propagate and distribute plant material to farmers, and provide the necessary training to cultivate/harvest the crop, ensuring agricultural best practice. In turn, this will improve local systems of agricultural production, harvesting and extraction technology and result in substantive up-skilling of the local rural population. In addition, we will devise agro-economic models of mint crop production, and develop business plans and marketing strategies to guide emerging local business ventures. This project will ensure that sustainable financial benefits accrue principally to local communities in Uganda, via CE groups set up to grow, harvest and exploit new mint crops. The project will explore the development of products for sale in collaboration with local-based partners, enabling rural populations in Uganda to benefit sustainably from science-based enhanced production of mint essential oils.

This multi-facetted proposal aims to increase production of the natural oil compounds, menthol and nepetalactone, in Mentha species and then utilise these terpenoids to create as high-value products for the rural Ugandan economy.
We will build a collection of Mentha species and characterise their natural oils and suitability for growth in Uganda. Correlation of trichome density with oil production will allow a simple method to be used in Uganda to identify promising new species. We will also use metabolic engineering to increase menthol yields by genetic modification in the M.x piperita and M. longifolia backgrounds. Based on current knowledge and flux control theory, four genes will be targeted for overexpression individually and in combination and the outputs assessed. From this work, tissue-culture regenerated vegetative plantlets will be produced which can be transported to Uganda for further evaluation.
Ugandan field trials will explore different growth conditions and we will measure biomass, oil yield and oil composition. These trials will include M.suaveolens that produces nepetalactone isomers in high amounts. The latter compound is a promising insect repellent and will be evaluated against mosquitos and other important disease vectors using WHO protocols with DEET as a control.
Building on the optimised production of menthol and nepetalactone will be their commercial utilisation in the local Ugandan economy. Menthol will be utilised in selected food/drink products to replace expensive imported material. Nepetalactone will be examined for safety and effectiveness in lotions or as sprays for bedding and clothes. These will represent significant additions to the rural economy. At the same time, there will be important transfer of technology and training of Ugandan scientists, enabling them to benefit sustainably from the project outputs.

Local communities in Sub-Saharan Africa face many social and economic challenges that contribute significantly to poverty and low life expectancy. These include depressed agriculture through falling prices of traditional crops, inefficient agricultural practices among rural farmers, adverse effects of climate change, high levels of school drop-outs, youth unemployment and rural de-population. However, there are significant opportunities to improve living standards. In particular, the good quality soils and environmental conditions, coupled with large areas of available arable land and a skilled rural labour force, could enable African communities to cultivate and market feedstocks produced from locally-grown crop plants, generating financial revenue, employment and improved quality of life.
Our vision for improving social conditions in rural Uganda takes of account these challenges and opportunities of the region. This project will combine a high-quality scientific research programme with engagement, training and commercialisation activities to enable local rural Ugandan communities to develop and market essential oil feedstocks from Mint (Mentha) plants, with the aim to develop novel products containing mint oils for local commercial benefit. Collaboration with academic partners in Makerere University, Kampala, Uganda is an essential component of the project, and will involve sharing of skills in plant molecular biology, analytical chemistry, crop viability trials, insect repellence trials and food technology. Cardiff School of Biosciences will offer training to researchers in the current methodology for metabolic engineering to create transgenic plant lines, which will enable them to put such techniques into practice in the newly equipped (World Bank funded) molecular biology lab facilities in MaRCCI (Regional Centre for Crop Improvement).
As our collaborative partner in a previous project CEMPOP Uganda Ltd met with women's groups and community leaders in rural Uganda confirming the need to provide employment and sustainable incomes in rural communities. In response to such local needs, in 2013 our Ugandan partners initiated economically successful schemes producing high value crops of strawberries, ginger and red papaya by youth and women on small holding farm. Fertile land is available for small-scale cultivation, with low opportunity cost or at low rental, due to recent falls in world prices for Uganda's cash crops. This creates the opportunity to utilize now-dormant agricultural land to grow novel non-food crops for industrial markets. CEMPOP's role in the Project will include liaison with local community leaders and groups, as they have over the past 2 years, to establish mint farming as a new income source and to create Community Enterprise groups to manage the emerging business ventures based on mint oil products being developed by this project.
Market research indicated a rising demand for health foods/drinks and personal care products which is currently met by imported products and materials. Such demand is coupled with rising incomes and lifestyles in Kampala but is evident also to a limited extent in rural communities. This confirms the opportunity for sustainable production of plant essential oils as a feedstock for locally produced alternatives to imported goods. Both farming communities and new business ventures would benefit by exploiting such novel markets. We favour the model of Community Enterprise groups to empower local people to create novel business ventures. Although community cooperatives have been formed to support tourism-related activities, social enterprise groups growing novel "industrial" crops such as plant oils do not currently exist in Uganda. We will exploit this opportunity in this proposal, with the aim to use high-quality science to capitalise on the large market ($800m p.a.) for mint oil products through community enterprise to improve the lives of rural Ugandan communities.