PRODUCTION OF YOGHURT FROM MILK EXTRACT OF TIGER-NUT (CYPERUS ESCULENTUS) USING LACTIC ACID PRODUCING BACTERIA ISOLATED FROM LOCALLY FERMENTED MILK (NONO)

Yoghurt is known to have medical uses for a variety of gastrointestinal conditions, although most yoghurt consumed are produced using the diary source of milk. In this research, yoghurt was produced from tiger nut milk extract by fermentation using starter culture containing Lactobacillus bulgaricus and Streptococuss thermophilus at 37oC for 4 hours. Lactobacillus bulgaricus and Streptococus sthermophilus were isolated and identified culturally, morphologically and biochemically, which were used for the fermentation. The inoculation of the starter cultures was divided into Sample A containing Lactobacillus bulgaricus as starter culture, Sample B containing Streptococuss thermophilus as starter culture and Sample C containing Lactobacillus bulgaricus and Streptococuss thermophilusas starter cultures. The tiger nut yoghurt produced was analyzed for its physicochemical, proximate and organoleptical qualities (sensory evaluation), in comparison with a popular yoghurt brand sold (dairy source of milk) in Keffi labelled as Sample D. The result obtained showed no significant difference (p>0.05) between the Ash content, Carbohydrate and Moisture content of all yoghurt samples but there were significant differences (p<0.05) between the protein, crude fibre and fat content of Samples C and D. The pH of all samples was between 4.0-4.5 and titratable acidity between 0.91-0.95. For mineral compositions there were significant differences (p<0.05) between the potassium contents of Samples C and D, calcium and sodium contents of B and D, and phosphorus of D while there were no significant difference (p>0.05) between the calcium and Sodium content of Sample A and C, potassium content of A and B and Phosphorus of A, B and C. Also the Organoleptic result showed no significant difference (P>0.05) in texture and taste except for appearance, consistency and overall acceptance which showed significant difference (p<0.05). From the result of this research, yoghurt can be produced by substituting cow milk with tiger nut milk.