Nunu, a spontaneously fermented yoghurt-like product, is produced and consumed in parts of West Africa. A total of 373 predominant lactic acid bacteria (LAB) previously isolated and identified from Nunu product were assessed in vitro for their technological properties (acidification, exopolysaccharides production, lipolysis, proteolysis and antimicrobial activities). Following the determination of technological properties, Lactobacillus fermentum 22-16, Lactobacillus plantarum 8-2, Lactobacillus helveticus 22-7, and Leuconostoc mesenteroides 14-11 were used as single and combined starter cultures for Nunu fermentation. Starter culture fermented Nunu samples were assessed for amino acids profile and rate of acidification and were subsequently evaluated for consumer acceptability. For acidification properties, 82%, 59%, 34%, and 20% of strains belonging to Lactobacillus helveticus, L. plantarum, L. fermentum, and Leu. mesenteriodes, respectively, demonstrated fast acidification properties. High proteolytic activity (100 to 150？μg/mL) was observed for 50% Leu. mesenteroides, 40% L. fermentum, 41% L. helveticus, 27% L. plantarum, and 10% Ent. faecium species. In starter culture fermented Nunu samples, all amino acids determined were detected in Nunu fermented with single starters of L. plantarum and L. helveticus and combined starter of L. fermntum and L. helveticus. Consumer sensory analysis showed varying degrees of acceptability for Nunu fermented with the different starter cultures. 1. Introduction Nunu is a spontaneously fermented milk (yoghurt-like) product in Ghana and other parts of West Africa including Nigeria and Burkina Faso. Unlike other African fermented milk products where milk of goats, sheep, and camels is used, Nunu is solely prepared from cow milk. The traditional processing of Nunu involves collecting fresh cow milk into containers and then allowing it to ferment for a day or two days at ambient temperature. Nunu is yoghurt-like in taste (a sharp acid taste) and it can be taken alone or with Fura [1, 2]. Like many other spontaneously fermented foods in Africa, the production of Nunu is largely home-based and the fermentation is spontaneous. Thus, starter cultures are not available, but old stocks of previous ferments and fermentation containers are used to initiate fermentation in new batches. The dependence on such undefined and diverse microbial consortium during Nunu fermentation may result in product of variable quality and stability. Currently, there is no information on the use of starter cultures for Nunu fermentation. However,
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