Traditional preparation of Marula wine 61 Nutrition & Food Science Vol. 38 No. 1, 2008 pp. 61-69 # Emerald Group Publishing Limited 0034-6659 DOI 10.1108/00346650810848025 Studies on the physico-chemical, nutritional and microbiological changes during the traditional preparation of Marula wine in Gwanda, Zimbabwe Nomusa R. Dlamini and Shadreck Dube Department of Applied Biology and Biochemistry, National University of Science and Technology, Bulawayo, Zimbabwe Abstract Purpose – The aim of the study is to determine the microbial, physico-chemical and nutritional changes that take place during the four-day traditional preparation of wine from the fruits of Marula (Sclerocarya birrea subspecies Caffra) tree in Zimbabwe. It must be noted that Marula is documented as a drought-resistant plant. Design/methodology/approach – The fruits used in the study were taken from four trees growing in different locations. The fermenting microbial populations were isolated using potato dextrose, tomato juice and nutrient agars, and then identified to genus level using simple biochemical tests. The physico-chemical changes determined were pH, titratable acidity, sugar and alcohol content. The alcohol content was determined using the Anton Paar beer analyzer, while nutritional changes, evaluated as changes in ascorbic acid (vitamin C) levels, were determined using the 2, 6 dichlorophenolindophenol titrimetric method. Findings – During fermentation there was a gradual decrease in the bacterial population, and an increase in yeast counts. The pH and sugar contents decreased, while the average alcohol content increased to an average 2 per cent. The fermented Marula juice retained 72 per cent of the initial ascorbic acid content (a decrease from 133 to 96 mg/100 g) compared with orange juice subjected to similar conditions, which retained 40 per cent ascorbic acid levels (decrease from 60 to 24 mg/100 g). Originality/value – The low pH of Marula wine could contribute to the microbiological safety of the product and relative stability of ascorbic acid. Marula wine produced after four days of fermentation is still an importance source of ascorbic acid. Keywords Food testing, Vitamins, Wine making, Fermentation, Zimbabwe Paper type Research paper Introduction The Marula tree (Sclerocarya birrea subspecies caffra) known as Umganu in Ndebele and Morula in Suthu, grows indigenously in Zimbabwe especially in the Middle and Lowveld. This region covers the provinces of Masvingo, Matabeleland North and South and parts of Midlands. The tree is widely distributed throughout Africa, from South Africa into Ethiopia and Sudan, it prefers a warm frost-free climate, and is drought resistant (Weinert et al., 1990). The Marula tree produces round to oval fruits that ripen between the months of February and May (Tredgold, 1986). The fruits are pale yellow when ready and fall to the ground from where they are picked. The juice of this fruit has a sweet-sour taste and is enjoyed by both adults and children (Tredgold, 1986). The Marula juice has traditionally been prepared to produce two types of beverages, one is a nutritious non-alcoholic drink which can be taken by both adults and children, while the other is an alcoholic drink for exclusive adult consumption (Tredgold, 1986). The length of fermentation period determines the type of beverage to The current issue and full text archive of this journal is available at www.emeraldinsight.com/0034-6659.htm