Optimization of Lactic Acid Fermentation from Overriped Plantain Using Response Surface Methodology (RSM)
Alao Adeyinka Idowu,
Agarry Samuel Enahoro,
Afolabi Tinuade Jolaade
Issue:
Volume 7, Issue 1, June 2023
Pages:
1-9
Received:
30 November 2022
Accepted:
23 December 2022
Published:
24 March 2023
Abstract: Lactic acid is a building block chemical used by many manufacturing industries. The search for cheap biochemical feedstock and process is of great concern to lactic acid producing industries. Plantain is a rich source of carbohydrate but the overriped plantains are thrown away as waste because of their non-firmness. This study evaluates the utilization of overripe plantain as biochemical feedstock for optimum production of lactic acid. Optimization of lactic acid production with overriped plantain was studied using Response Surface Methodology. The initial pH and reducing sugar content of the plantain hydrolysate were 4.89 and 166.05 g/l respectively. The response of lactic acid concentration to four factors: substrate concentration (138.25 – 166.05 g/L), initial pH (4 – 8), fermentation temperature (30 – 50°C) and time (24 – 168 h) was studied. The lactic acid concentration ranged from 123.50 – 163.00 g/l. A statistically significant [(Pmodel>F) < 0.0001] second order quadratic polynomial regression model was obtained for lactic acid production; the R2 and adjusted-R2 were 0.9935 and 0.9896 respectively. Numerical optimization was used to obtain optimum lactic acid production (157.53 g/ L) at glucose concentration, pH, temperature and time of 159.10 g/l, 7.0, 42.3°C and 60 h respectively. Overriped plantain was a good biochemical feedstock for lactic acid production.
Abstract: Lactic acid is a building block chemical used by many manufacturing industries. The search for cheap biochemical feedstock and process is of great concern to lactic acid producing industries. Plantain is a rich source of carbohydrate but the overriped plantains are thrown away as waste because of their non-firmness. This study evaluates the utiliza...
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Evaluation of Thin Layer Models for Simulating Drying Kinetics of Black Nightshade Seeds in a Solar-Exhaust Gas Greenhouse Dryer
George Onyango Orido,
Erick Kiplangat Ronoh,
Patrick Ochuodho Ajwang,
Benson Baari Gathitu
Issue:
Volume 7, Issue 1, June 2023
Pages:
10-31
Received:
10 April 2023
Accepted:
25 April 2023
Published:
10 May 2023
Abstract: The current study aimed to use, besides solar, waste heat from exhaust gas of a diesel engine operated for milling of grain, to dry black nightshade seeds. Assessment of thin layer models for simulating drying kinetics of black nightshade seeds was performed in a solar-exhaust gas greenhouse dryer operated on solar; solar-exhaust gas; and exhaust gas modes. In solar mode, seeds took 11 hours to reach a final moisture content of 7.13% (db) from an initial one of 89.34% (db). In solar-exhaust gas mode seeds were dried from an initial moisture content of 92.57% (db) to a final one of 6.07% (db) in 10 hours. In exhaust gas mode it took 14 hours to dry black nightshade seeds from an initial moisture content of 88.84% (db) to a final one of 9.42% (db). Newton, Page, Logarithmic, and Henderson and Pabis thin layer drying models were fitted to experimental data and the best model was selected based on low root mean squared error (RMSE) and interpretation of residual plots. To best explain the prediction of thin layer drying of black nightshade seeds, based on the lowest value of RMSE, Page model was found suitable for solar mode with RMSE of 0.01147206, Logarithmic model was found suitable for both solar-exhaust gas and exhaust gas modes of drying with RMSE of 0.0172098 and 0.02315325 respectively. In conclusion, the thin layer modeling approach can be used to provide design data for a solar-exhaust gas greenhouse dryer.
Abstract: The current study aimed to use, besides solar, waste heat from exhaust gas of a diesel engine operated for milling of grain, to dry black nightshade seeds. Assessment of thin layer models for simulating drying kinetics of black nightshade seeds was performed in a solar-exhaust gas greenhouse dryer operated on solar; solar-exhaust gas; and exhaust g...
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