Biochemical Properties Of Isolated Yeast From Raphia Hookeri (Raphia Palm Wine And Eliase Guinensis (Oil Palm Wine)

This study was conducted to comparatively evaluate the biochemical characteristics of industrial yeast and locally isolated yeast from palm wine. Palm wine samples were collected from Ikwuano/Isi-ala Ngwa areas of Abia state during the early hours of the morning. Samples collected were taken immediately to the laboratory for yeast isolation. Commercial yeast and isolated yeast were then tested for Ethanol tolerance, ethanol production capacity, sugar utilization, flocculence, and elevated temperature growth, dough leavening capacity, bread production and sensory evaluation. Results obtained were subjected to statistical analysis and data was presented in tables and figures. From the result, the isolated yeast samples had high ethanol tolerance at 14 % (v/v) ethanol while the commercial yeast sample used as control could not tolerate ethanol higher than 12 % (v/v). Also, the isolated yeast sample had the ability to produce approximately 5 % alcohol in a period of seven days. While the industrial yeast sample used as control was able to produce approximately 6 % alcohol within the same period of seven days. The result of sugar utilization test showed that yeast samples were able to assimilate Glucose, Sucrose, Maltose, Galactose and Raffinose and showed negative utilization of carbon for Lactose, Mannitol and Xylose sugars. All yeast samples showed flocculation abilities. Isolated yeast particularly the yeast isolated from the Raffia palm wine (Ngwo) showed good flocculation ability highly useful in breweries for brewing beer and wine. Test for the ability of yeast samples to grow at varying conditions, the isolated yeast was positive for growth in 3 % ethanol, 50 % glucose, temperatures of 30 °C and 35 °C and in 3 % sodium chloride while in 42 °C and 10 % NaCl isolated yeast was Negative.