Development, nutritional evaluation, and consumer acceptability of non-alcoholic fermented beverages made from Sclerocarya birrea (Marula) and provitamins A biofortified maize

The fruits of the Marula plant are rich in ascorbic acid, containing three times the vitamin C found in orange juice, along with various minerals and antioxidants. Despite these nutritional benefits, research indicates that the full potential of Marula fruit still needs to be explored, posing a risk to the plant's sustainability. In Kwa-Zulu Natal (KZN), there is a growing trend of utilising Marula fruits in producing "utshwala bamaganu," a locally favoured alcoholic beverage fermented from fruits and sweetened with sugar. However, households with limited alcohol consumption often do not partake in this beverage. In KZN, most non-alcoholic fermented drinks are maize-based, raising concerns about potential vitamin A deficiencies in rural areas where excessive consumption of these beverages may displace more nutritious food options. This study addresses these issues by developing non-alcoholic fermented beverages incorporating Marula fruits and Provitamin A biofortified maize. Using an experimental design, recipes sourced from key informants were combined, standardised, and modified by substituting traditional white maize meals with 100 % Provitamin A biofortified maize to enhance the nutritional profile of the beverages. At full concentration, Marula juices served as both the sugar source and fermenting agent, while other ingredients remained unchanged. Various fermentation techniques—including roasting, milling, and boiling—were employed to develop the three beverages. The beverage samples were analysed for nutritional content, focusing on vitamin A, amino acids, and mineral compositions. Following analysis, 60 consumers participated in sensory evaluations using a 5-point hedonic scale to provide feedback. The results revealed significant nutritional improvements, particularly in essential minerals like zinc and iron; Sample 2 exhibited the highest iron content at 53 ppm. Roasting significantly enhanced flavour and overall acceptability, with consumers rating Sample 1 the highest. However, vitamin A levels across all samples were below detection limits, likely due to degradation from heat exposure. This study highlights the potential of incorporating Marula and biofortified maize into fermented beverages to enhance food and nutrition security. The findings suggest that optimizing fermentation and processing methods could improve nutritional benefits, although retaining vitamin A remains challenging.