Cyanogenic glycosides are natural phytotoxins produced by over 2000 plant species, many of which are consumed by humans. The important food crops that contain cyanogenic glycosides include cassava (Manihot esculenta), sorghum (Sorghum bicolor), cocoyam (Colocasia esculenta L. and Xanthosoma sagittifolium L.), bamboo (Bambusa vulgaris), apple (Malus domestica), and apricot (Prunus armeniaca). Cyanogenic glycosides and their derivatives have amino acid-derived aglycones, which spontaneously degrade to release highly toxic hydrogen cyanide (HCN). Dietary cyanide exposure has been associated with several health challenges such as acute cyanide poisoning, growth retardation, and neurological disorders. This chapter will introduce general cyanogenesis principles, highlight major food plants with lethal cyanide levels, and provide epidemiological-based health conditions linked to cyanide intake. Furthermore, strategies for elimination of cyanogens from food crops, such as processing technologies, will be discussed. Finally, the chapter will analyze the role of cyanogenic plants in ensuring food security among resource-poor communities.

Water plays an important role in food security and provides the basis for healthy ecosystems and human well-being. The relationship between water and food production is key to creating resilient and sustainable food systems. This chapter will discuss the effects of water quality and scarcity with respect to food security in Africa. The effects of water availability and its usage in the African landscape and how this has impacted food security will be highlighted. Lastly, issues concerning water pollution and food safety will be tackled to identify knowledge gaps that impede food security in Africa in its efforts toward attaining the United Nations Sustainable Development Goals.

Terrestrial orchid tubers are an important source of food in some parts of Africa and are traditionally included in the diets of most rural communities in Malawi. However, there is limited information on the nutritional and phytochemical content of the Malawian orchids to substantiate their traditional use. The present study evaluates the nutritional and phytochemical variation of four orchid species: Disa zombica, Satyrium buchananii, Satyrium carsonii, and Satyrium trinerve, collected from the same ecological zone of Malawi. The proximate content, minerals, phytochemicals, and functional properties were analysed using official procedures. Protein ranged from 2.19% to 4.65%, whereas carbohydrate ranged from 65.24% to 80.22%, with S. carsonii and S. trinerve registering the highest protein and carbohydrate contents, respectively. Iron and potassium were highest in D. zombica, while sodium and calcium were highest in S. buchananii. The total phenolics ranged from 228.56 to 500.00 mg GAE/100 g, with D. zombica registering the highest. The water absorption capacity ranged from 4.10 to 10.88 g/g. Despite variable levels, the study provides evidence that orchid species contain essential nutrients and phytochemicals important for human nutrition and health. Furthermore, the functional properties can be utilised in the development of food products, such as baked products.

There have been increasing consumer preferences for foods and beverages prepared with natural additives. Regular consumption of functional foods that contain significant amounts of bioactive phytochemicals has been associated with a reduced risk of several types of non-communicable diseases. However, under certain circumstances, some phytochemical food additives and ingredients are known to be potentially toxic. This chapter will discuss various categories of phytochemical additives based on their chemical structural classes and mode of action, the claimed health benefits, and the potential toxicity of each class. It will also provide a review of the studies on important natural food additives that are used as preservatives, coloring agents, sweeteners and anti-caking agents. Finally, current challenges and future research directions for phytochemical food additives will be presented.

Terrestrial orchid tubers are an important source of food in some parts of Africa and are traditionally included in the diets of most rural communities in Malawi. However, there is limited information on the nutritional and phytochemical content of the Malawian orchids to substantiate their traditional use. The present study evaluates the nutritional and phytochemical variation of four orchid species: Disa zombica, Satyrium buchananii, Satyrium carsonii, and Satyrium trinerve, collected from the same ecological zone of Malawi. The proximate content, minerals, phytochemicals, and functional properties were analysed using official procedures. Protein ranged from 2.19% to 4.65%, whereas carbohydrate ranged from 65.24% to 80.22%, with S. carsonii and S. trinerve registering the highest protein and carbohydrate contents, respectively. Iron and potassium were highest in D. zombica, while sodium and calcium were highest in S. buchananii. The total phenolics ranged from 228.56 to 500.00 mg GAE/100 g, with D. zombica registering the highest. The water absorption capacity ranged from 4.10 to 10.88 g/g. Albeit variable levels, the study provides evidence that orchid species contain essential nutrients and phytochemicals important for human nutrition and health. Furthermore, the functional properties can be utilised in the development of food products, such as baked products.