ABSTRACT

Milk and yogurt are important elements of the human diet, due to their high nutritional value and their appealing sensory properties. In Nigeria, some animal milk are not usually available and also have other limitations for their wider use. It is necessary to consider other available and less expensive source of vegetable protein such as soybean and beetroot. This study deals with the production and quality evaluation of soy-beetroot yoghurt. Five blends of the soy-beetroot yoghurt were formulated with the ratio of soybean: yoghurt as 100:0 (AL2), 95:5 (AL3), 90:10 (AL4), 85:15 (AL5), 80:20 (AL6) and 100% cow milk (AL1) used as control. There was significant (p<0.05) difference in the proximate composition of the blends. The control sample (AL1) ranked highest in ash (0.66%), fat (1.82%), fibre (0.56%) and protein (5.95%). The values of AL6 for ash (0.55%), fibre (0.38%) and protein (3.63%) were close to that of the control. It also had more moisture and carbohydrate than the control. There was no growth of fungi or E. Coli in the blends. Lactobacillus spp was identified 1.0x105 Cfu/ml. The control was significantly (p<0.05) different and ranked highest in all sensory parameters. The highest among the composite yoghurts in appearance was AL2 (7.25), clarity (AL4:7.00), Taste (AL6:6.60), flavour (AL4:6.50), and mouthfeel (AL4:6.65). However, there was no significant difference in the appearance, clarity, flavour and mouthfeel of the yoghurt blends. AL1 (control) had general acceptability of 8.45 while AL6 followed closely with 6.95, all on a 9-point hedonic scale. This study suggests that the combination of soymilk and beetroot in the ratio of 80:20 can yield a nutritional composite yoghurt of acceptable organoleptic standard.