Addis Ababa University Libraries Electronic Thesis and Dissertations: AAU-ETD! >
Institute of Technology >
Thesis - Food Engineering >

Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/1588

Authors: Wondimagegen, Damtew
Advisors: Dr. Eng. Shimelis Admassu
Keywords: Baker’s yeast (saccharomayces cerevisiae)
molasses and Single protein
Copyright: 2008
Date Added: 1-Nov-2008
Publisher: Addis Ababa University
Abstract: Three yeast strains were used for biomass production of baker’s yeast using wine, brewer and baker’s yeast strains. The effect of growing yeast saccharomayces cerevisiae on cane molasses with respect to baker’s yeast production was assayed. All yeast strains were cultured in YPD microbiological media and cane molasses media; their growth properties and biomass yield were examined using different substrate concentration of cane molasses and different nitrogen source chemical compounds. The studies on the feasibility of different types of yeast growth on cane molasses has been analyzed here. As a result of the kinetics study of growth of three yeast strains shows that baker’s yeast strain gives the best results to know a generation time reduced high growth rate and a high quantity of biomass. The maximum biomass yield and protein concentration was obtained with the 5 %(w/v) cane molasses of bakers` yeast; the effect of different concentration of cane molasses (5%, 10% and 15% sugar concentration) on biomass yield and protein concentration of bakers, wine and brewery yeast strains were studied. Biomass and protein formation was affected by the type of nitrogen present in the medium; high yield of protein being achieved in fermentation medium containing 2 % (w/v) (NH4)2SO4. Conversely medium, containing potassium nitrate had suppressive effect of protein production. Baker’s yeast production was industrialized using baker’s yeast strain in 5%(w/v) cane molasses with addition of ammonium sulphate.The results obtained on industrial scale feasibility study shows that the unit costs for the baker’s yeast production are $2.4 per kilogram, while the local market price for the baker’s yeast is $7.00/kg. It has good market demand and profitability analysis also provides positive results.
Description: A Thesis Submitted to the School of Graduate Studies of Addis Ababa University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Food Engineering
URI: http://hdl.handle.net/123456789/1588
Appears in:Thesis - Food Engineering

Files in This Item:

File Description SizeFormat
Wondimagegen Damtew.pdf559.65 kBAdobe PDFView/Open

Items in the AAUL Digital Library are protected by copyright, with all rights reserved, unless otherwise indicated.


  Last updated: May 2010. Copyright © Addis Ababa University Libraries - Feedback