Physicochemical, Nutrient And Microbiological Analysis Of Oshikundu; A Cereal Based Fermented Beverage From Namibia

ABSTRACT

The aim of this study was to determine the physicochemical, nutrients, predominant microflora mainly looking at lactic acid bacteria and spoilage bacteria in Oshikundu samples collected from Omusati, Oshana, Ohangwena and Oshikoto regions. Oshikundu is brewed from pearl millet (Pennisetum glaucum L. R.Br.,) meal locally known as Mahangu, malted sorghum (Sorghum bicolor L. Moench), bran and water. Oshikundu pH ranged between 3.33 ± 0.127 in Oshana region and 3.60 ± 0.014 in Oshikoto region. Titratable acidity as lactic acid was found to be ranged between 1.20 % in Oshikoto and 1.68 % in Ohangwena region. Meanwhile acetic acid ranged between 0.10 % in Omusati and 0.30 % in Ohangwena region. The protein content ranged between 0.133 ± 0.007 and 0.178 ± 0.02 (mg/mL), insoluble fibre, 0.025 ± 0.01 % and 0.028 ± 0.004 %, energy, 46.8 ± 8.45 and 54.4 ± 4.17 (kJ/100 mL) on dry basis. Micro-nutrients including vitamin B1 and B2, were detected in Oshikundu. Minerals were analysed and revealed the presence of B, Ca, Cu, Fe, K, Mg, Mn, Na, S, Zn and P which was the highest (ranged between 3.914 ± 0.452 and 11.511 ± 7.264 ppm). The microflora of Oshikundu included 6 predominant Lactic acid bacteria (LAB): Lactobacillus plantarum, Lactococcus lactis ssp. lactis, Lactobacillus delbrueckii ssp. delbrueckii, Lactobacillus fermentum, Lactobacillus pentosus and Lactobacillus curvatus ssp. curvatus. Five bacterial species were identified that are likely to be responsible for Oshikundu spoilage; Enterobacter cloacae, Enterobacter sakazakii, Pseudomonas luteola, Pseudomonas aeruginosa and Serratia ficaria. Further studies on microflora, starch structure and characterization of flow behaviour are necessary in understanding the rheological properties of Oshikundu for process design and product quality evaluation.