Utilization of Banana Peel for Citric Acid Production on Solid-State Fermentation Using Aspergillus Niger
| dc.contributor.advisor | Eduardo, Ojito (Prof.) | |
| dc.contributor.author | Solomon, Kahsay | |
| dc.date.accessioned | 2019-01-16T10:13:40Z | |
| dc.date.accessioned | 2023-11-10T15:01:20Z | |
| dc.date.available | 2019-01-16T10:13:40Z | |
| dc.date.available | 2023-11-10T15:01:20Z | |
| dc.date.issued | 2018-06 | |
| dc.description.abstract | Citric acid is a tricarboxylic acid which is soluble in water with a pleasant taste. It is an important acid used in food Industries. It exists in nature when carbohydrates are oxidized to carbon dioxide. Because of its high solubility, palatability and low toxicity it can be used in food, biochemical, and pharmaceutical industries. The aim of this study is to produce citric acid by Aspergillus niger using banana peel as a substrate and to evaluate its quality and concentration. In this study, the utilization of banana peel to use as a raw material for citric acid production under different fermentation conditions with solid state fermentation method in the laboratory using 250 mL Erlenmeyer flask as the small-scale laboratory fermenter was investigated. Design of experiment (DOE) for response surface methodology (RSM) was used to analyze and optimize the simultaneous effect of solid substrate loading (18g, 36g, and 54 g), incubation time (3days, 6days and 9days) and fermentation temperature (25 ⁰C, 30 ⁰C and 35 ⁰C) on citric acid production. The minimum citric acid was found to be 28.39 g/L at 36 g, 3 days, and 25 ⁰C. A maximum citric acid yield of 45.55 g/l was achieved under optimal experimental conditions (36 g, 6 days and 30 ⁰C). A three-variable, three-level Box-Behnken design was used to develop a statistical model to describe the relationship between citric acid concentration and the chosen independent variables and to optimize the production of citric acid using RSM. The model was statistically significant (p ˂0.0001) with a low standard deviation (0.66). Besides, it did not show lack of fit (R 2 =0.9948) and the Pred R-Squared of 0.9353 is in reasonable agreement with the Adj R-Squared of 0.9880. Citric acid production was significant at moderate levels of solid loading, incubation time and fermentation temperature. From the model regression equation developed, the linear terms of temperature and time had a positive effect and a substrate loading had a negative effect on response yield. A maximum citric acid yield of 45.59 g/L was also achieved under selected optimum values (31.92 g, 5.82 days and 31.55 ⁰C) with high value of combined desirability. Validation of the statistical model showed an insignificant difference between experimental and model-predicted results | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/15763 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Citric acid | en_US |
| dc.subject | Aspergillus niger | en_US |
| dc.subject | Banana peel | en_US |
| dc.subject | Substrate | en_US |
| dc.subject | Solid State Fermentation | en_US |
| dc.title | Utilization of Banana Peel for Citric Acid Production on Solid-State Fermentation Using Aspergillus Niger | en_US |
| dc.type | Thesis | en_US |