Nutritional Composition, Microbiological Quality and Sensory Properties of Kunu-zaki Produced from Millet and Tigernut Blend

Abstract

Aims: To investigate the effect of supplementation of kunu-zaki with milk on its nutritional and microbiological qualities and overall acceptability.
 Place and Duration of Study: Department of Science Laboratory Technology, Faculty of Applied Sciences, Rufus Giwa Polytechnic, Owo, between April, 2019 and July, 2019.
 Methodology: The two (2) Kunu-zaki blends were produced by traditional fermentation method, thereafter, they were screened for the presence of microorganisms using pour plate method while colonial characteristics and biochemical tests (Sugar utilization, catalase, coagulase, oxidase) were done to confirm the identity of the organisms. The proximate composition (moisture, protein, lipid, ash, fibre and carbohydrate) of the samples were assayed using standard procedures. The sensory properties of the Kunu-zaki were assessed using a trained panel. Data were analyzed statistically using SPSS version 17.0 and the means separated using Duncan Multiple Range Test.
 Results: Coliforms and Enterobacteriacea were not found in the enriched and control Kunu-zaki samples. However, the highest total heterophilic bacterial count (107x103 cfu/ml) and lactic acid bacterial count (131 x103 cfu/ml) were found in sample B while the least counts were found in the control sample with 92 x103 cfu/ml and 122 x103 cfu/ml total bacterial and lactic acid bacterial counts respectively. Further, the highest fungal count was found in control sample (67 x103 sfu/ml) while the least count were observed on sample B (52 x103 sfu/ml). The control sample had the lowest pH 4.65 while sample C had the highest pH of 5.95. Also, the TTA ranged between 0.57% I sample C and 0.83% in control sample. A total of six (6) bacteria and six (6) fungi were isolated from the freshly prepared kunu-zaki-tigernut milk blends, they were Bacillus subtilis, Bacillus licheniformis, Micrococcus luteus, Lactobacillus acidophilus, Lactobacillus plantarum, Streptococcus species, Geotrichum candidum, Saccharomyces cerevisiae, Aspergillus niger, Rhizopus stolonifer, Fusarium and Penicillium species. The crude protein, moisture content and fat of the enriched Kunu-zaki were significantly (p≤0.05) higher than the control sample. Also, there was a reduction in fibre, ash and carbohydrate content of the enriched Kunu-zaki product compared with the control sample. The enriched Kunu-zaki samples had higher level of potassium, magnesium and phosphorus than the control Kunu-zaki while they had lower calcium and sodium concentrations. Kunu-zaki-tigernut milk blends had comparable rating to the control in appearance and aroma but had a higher rating for taste and overall acceptability.
 Conclusion: The enrichment of Kunu-zaki with tigernut milk had significant elevating effect on the nutrition and sensory properties of the Kunu-zaki and its overall acceptability.