Nutritional content of the African horned cucumber (Cucumis metuliferus E. May. Ex Naudin) fruit grown under varying fertiliser types and growing environments, and its potential role in human nutrition

The fruit sector is one of the key role players in food and nutritional security by supplying vital nutrients, increasing food availability, promoting dietary diversity, and contributing to economic stability. Currently, most fruit species that contribute to food and nutritional supply in the fruit industry are exotic varieties such as mangoes, oranges, grapes, and English cucumbers, owing to the established and reputable literature on their agronomic practices and protocols. To achieve food and nutritional security globally, the introduction of indigenous fruit crops, especially in regions where they are native, appear to be a promising strategy that could accelerate the attainment of Sustainable Development Goal 2 (Zero Hunger). Additionally, this inclusion may assist in complementing existing commercial crops to substantially boost communal nutrition and food diversity by offering phytochemicals, nutrients, and minerals, which are vital for sustained health and wellness. Among such crops is the African horned cucumber ( Cucumis metuliferus E. May. Ex Naudin), an indigenous fruit crop of Southern Africa claimed to be nutrient dense due to its abundance of vitamins and minerals, which human beings require in smaller and larger quantities daily. However, literature on the fruit’s biochemical content response when subjected to differing growing environments and the use of specific fertiliser types appears to be scanty. Therefore, the current study evaluated the impact of differing growing environments (greenhouse and shade net) and fertiliser types (organic and inorganic/chemical) on the biochemical constituents of African horned cucumber fruit. In addition, the fruit nutritional content was compared with the average recommended daily intake to determine its potential contribution to human health and nutrition. The results showed that a treatment combination of shade net and chemical fertilisers increased phosphorus (577.7 mg/100g DW) and potassium (1074 mg/100g DW) compared to other treatments. As a result, growers are encouraged to consider the greenhouse environment combined with chemical fertilisers for maximising phytochemicals such as total phenols and vitamin C, whereas the treatment combination of shade net and chemical fertiliser appeared to be the best for maximising minerals such as calcium, phosphorus, and iron.