Prediction of significant factors in the production of ethanol by ragi tapai co-culture using Taguchi methodology
Ethanol production by co-culture of ragi tapai and Saccharomyces cerevisiae from unhydrolyzed cassava starch without addition of enzymes was conducted in a 2 L batch fermentor. Taguchi’s method with orthogonal array of L8 was applied in design of experiment (DOE) and the results were analyzed usi...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Academic Journals
2011
|
| Subjects: | |
| Online Access: | http://irep.iium.edu.my/13696/ http://irep.iium.edu.my/13696/ http://irep.iium.edu.my/13696/ http://irep.iium.edu.my/13696/1/Azlen_Suhaida_AJB.pdf |
| Summary: | Ethanol production by co-culture of ragi tapai and Saccharomyces cerevisiae from unhydrolyzed
cassava starch without addition of enzymes was conducted in a 2 L batch fermentor. Taguchi’s method
with orthogonal array of L8 was applied in design of experiment (DOE) and the results were analyzed
using MINITAB v14 software. Seven factors: Nitrogen-phosphorus-potassium (NPK), urea, fermentation
temperature, ragi tapai concentration, S. cerevisiae concentration, agitation and co-culturing time were
varied at two levels for each factor. The significant factors for the production of ethanol were
determined by setting S/N ratio to “larger-is-better” for high yield ethanol and “smaller-is-better” for low
yield of ethanol byproducts. The optimum values obtained for each factor were similar to each other.
Both have optimum factors of: Urea at 0.8 w/w%, dry ragi tapai and S. cerevisiae concentrations each at
10 w/w%, co-culturing time at 3 h gap, NPK at 0.09 w/w% and agitation speed at 100 rpm. The
fermentation temperature for high ethanol yield was 35°C, whereas for the byproducts was 30°C. From
the validation experiment conducted at 30°C in 10 L fermentor, the ethanol concentration obtained was
68.00 g/L, while all byproducts concentrations were below 9.00 g/L at the end of the fermentation. |
|---|