Chemical analysis to promote the use of wild fruits from Mozambique

Abstract: Popular Abstract in English Wild fruits trees species are widely distributed throughout the African countries. Many of these trees species produce fruits, which are used by the local communities to greater or less degrees. The importance of wild fruits in the diet depends to a large extent on the availability of the fruits, since cultivated fruit trees are not particularly common in the dry regions of the countries. The goals of this work were to perform a study on traditional utilization of wild fruits in Mozambique and to generate data on the composition and other characteristics of five wild fruits as a basis for the selection of fruits suitable for processing and increased utilisation and consumption of indigenous fruits. Fruits of Adansonia digitata (n´buvu), Landolphia kirkii (vungwa), Salacia kraussii (psincha), Sclerocarya birrea (canhi), and Vangueria infausta (pfilwa), were selected for this research. When the wild fruits were collected in the different districts, local people were interviewed about the traditional use of the fruits. The fruits are eaten raw, pressed to juice, fermented to alcohol beverages, cooked, or used as flour to make porridge. The seeds and kernels are often used in times of drought when the production of peanuts is low; the seeds can be ground roasted to make a kind of coffee, and the kernels of A. digitata and S. birrea may also be roasted to be eaten as snacks or ground in a bowl, mixed with water, boiled and consumed with local plant food. In general most people know that fruits are associated with potential health benefits. Researchers has shown that a wide range of wild fruits have the potential to provide rural households with free foods to meet their nutritional and medicinal needs. The disadvantages of the selected fruits are that they grow and ripen during a very short period of the year and that normally their shelf-life is short. Different analytical methods were used to evaluate the nutritional components and other characteristics of some wild fruits. For the fruit processing industry, data on sugar content, pH and moisture are essential characteristics. They play an important part in the perception of fruit quality indicating the possibility for future use of these wild fruits. The sugar content is important for the development of the aroma and taste, and in product development it is important to find a good balance between for example pH and sugars to receive an optimal taste. The highest total sugar content was found in A. digitata and L. kirkii, more than 10g/100 g. Organic acids such as citric and malic acid influence flavor and aroma and are responsible for many characteristic fruity tastes; they were found in all fruits in this study. The parameters above have been reported to influence shelf life, stability and microbiologic safety. Most of the fruit pulps were juicy except of A. digitata, which was very dry; the moisture content was only around 10%. The fat and protein contents in the pulps were low, which is common in fruits. The pulps of A. digitata and V. infausta contained considerable amounts of dietary fibres. The content of the mineral in the kernels such as calcium, iron and zinc were found in considerable levels and the have great contribution for many functions on the human body. Consumption for example of 100 g A. digitata pulp, can provide around 30% of recommended intake of calcium for pregnant women and children, and 23% of the iron for 4 to 13 years old children. Consumption of 40 g A. digitata kernels can provide 20 to 25% of the recommended intake of iron for children and 16 to 20% from S. birrea kernels. In addition the recommended intake of zinc provided 20 to 44% from A. digitata, and 16 to 36 % from S. birrea kernels for children and pregnant women. The fat content in A. digitata and S. birrea kernels was high around 40 to 50%. Interestingly the fatty acid composition in A. digitata can be compared with that in peanuts, while S. birrea can be compared with olive oil. A. digitata kernels contained the essential fatty acids linoleic and linolenic acids and S. birrea kernels contained only the linoleic acids. Consumption of 40 g A. digitata kernels can cover 60 to 90% of the daily intake of essential fatty acids for those aged 4 to 13 years, and pregnant women. Protein is one of the most crucial nutrients to the human body improving varying aspects of health. The protein content in the kernels of A. digitata and S. birrea was around 30 to 40%. In addition, the levels of essential amino acids in the kernels were comparable with the amino acid requirements stated by the World Health Organization (WHO). For children aged 4 to 8 years, 81 and 66% of the recommended intake may be covered by the consumption of 40 g A. digitata kernels and S. birrea kernels, respectively. The contribution to recommended intake for older children and pregnant women is lower, but it may be possible for these groups to increase their intake of kernels, especially if they are eaten as a snack. The results of this study will be vital in efforts to promote use of these wild fruits. The data can be used for the estimation of dietary intakes, and for education of local communities with regard to the nutritional benefits of free sources of food in their environment. The findings indicate that the nutrient contents of the fruits may help to meet the dietary requirements for children and pregnant women in rural areas. In addition they may promote the use of wild fruits and their kernels, and can form the basis for the selection of fruits for further processing, to extend shelf-life and to manufacture new products. Initiatives should be put in place for the selection and domestication of wild fruits trees.