Finding a stable source of antioxidants and Vitamin C in Africa
V
itamin C, or Ascorbic acid, is an essential dietary ingredient. It is vital for wound healing and is an important physiological antioxidant, which may help to prevent or delay the development of certain cancers, cardiovascular disease, and other diseases in which oxidative stress plays a causal role. It helps to regenerate Vitamin E too, and also helps us to absorb the form of iron that we get from vegetables. Penny Hiwilepo‐van Hal from Namibia has been investigating the Vitamin C characteristics of the Marula Fruit Sclerocarya birrea subsp. caffar. The fruit has a Vitamin C content of more than 4 times that of oranges and grows on a tree which is widespread in Africa from Ethiopia in the north to KwaZulu-Natal in the south. ”The problem in warm climates”, says Penny, ”is the degradation of Vitamin C in many fruit products during processing or storage”. The good news is that she discovered that the degradation rate of Vitamin C in Marula was less influenced by the temperature at which it was processed or stored when compared with other fruits like mango and guava. In fact it is 15 times more stable to heat than these other fruits. Marula juice can be fermented to give a refreshing drink and in many parts of
southern Africa, including Botswana, South Africa, Swaziland, Namibia and Zimbabwe, traditional Marula beer and wine is produced and traded. The alcohol content in Marula wine is about 5% and it depends on the fermentation time. The other good news is that naturally fermented Marula retains its antioxidant activity. Specifically, Penny Hiwilepo‐van Hal reports that ”to produce an alcoholic product high in antioxidant you should ferment at temperatures ranging between 30 and 40 degrees for 4–6 days.
penny hiwilepo-van hal Project: Kinetics of thermal degradation of Vitamin C in Marula Fruit (Sclerocarya birrea subsp. caffra) as compared to other selected tropical fruits. Institution: Department of Food Science and Technology, Faculty of Agriculture and Natural Resources, University of Namibia. Country: Namibia Grants Awarded: 2011
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