Browsing by Author "Masanja, E"

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    Characterization of Sisal Boles for Production of Polylactic Acid (PLA)
    (2018) Msuya, N; Katima, J.H.Y; Minja, R. J. A; Masanja, E; Temu, A.K
    Biobased biodegradable plastics (bioplastics) show a large range of properties which can compete with non-biodegradable thermoplastics in packaging, textile and biomedical applications. Polylactic acid (PLA) is one of the most promising bioplastics, which are synthesized by polymerization of Lactic Acid (LA). Traditionally LA is produced from pure sugars and food crop sources like potatoes, cassava, corn, wheat, rice, sugar beet, sugar cane, and others. However, because of competition with existing uses, alternatives raw materials are being researched. One such alternative is the sisal boles. Sisal bole is part of the 98% of the sisal biomass which is traditionally counted as waste. Sisal boles as raw material for PLA are advantageous since it is not competing with food. This work characterizes sisal boles juice and its potential to produce biodegradable plastics. The sisal boles juice was extracted from chopped autoclaved boles using a hydraulic pressing machine. The juice was hydrolyzed to allow the sugar polymers to break into monomer sugar. The boles have been found to comprise of up to 97.94% (w/v) organic matters and total sugar content in juice of up to 30% (w/v). The produced juice mineral content levels were within the recommended working fermentation range with necessary nutrients for LA producing microorganisms. Sisal boles can therefore be one of the good raw materials for lactic acid production
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    Lactic Acid Production from Sisal Boles Juice by Lactobacillus Delbrueckii Sp. Delbrueckii
    (2018) Msuya, N; Katima, J.H.Y; Masanja, E; Minja, R. J. A; Temu, A.K
    The use of different concentrations of sugar from sisal boles juice for production of Lactic acid (LA) using Lactic Acid Bacteria (LAB) has been studied with the intention of analysing the effect of initial sugar concentration, process temperature and initial medium pH on the produced lactic acid concentration, yield and productivity. All the linear variables (initial sugar conc., pH and temperature), two way and three way interactions were statistically significant for LA yield at p-values of less than 0.05 with correlation coefficient of 0.997. There was no significant effect on LA productivity of three way interactions (Temp.*pH*Initial Conc.). Maximum condition for production of LA occurred at a temperature of 37°C, initial pH of 6 and initial sugar concentration of 120 g/L which corresponded with the highest LA concentration of more than 24 g/Land a yield of 93%. This study shows that sisal boles juice has potential to produce LA.
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    Separation and Purification of Lactic Acid from Sisal Wastes
    (2018) Msuya, N; Minja, R. J. A; Katima, J.H.Y; Masanja, E; Temu, A.K
    The aim of this paper was separation and purification of Lactic acid (LA) produced from Sisal Waste by investigating the influence of modified hybrid short path evaporation (M-HSPE) system on the concentration of LA. A 22 full factorial design was used to study the influence of temperature and time on the concentration of LA and % mass obtained in distillate and residue flask. Minitab V.17 was used in designing the LA concentration experiments and in calculating the effect of each variable and their interactions. Higher LA concentration of 108 g/L occurred at system temperature of 47°C for 25 minutes. This represented a concentration of 4.5 times the initial concentration (24 g/L) with 100% recovery in residues stream/ flask. Therefore, the M-HSPE system was able to concentrate LA to almost twice the original hybrid short path evaporation (HSPE) system. According to ANOVA, LA concentration presented a correlation coefficient of 0.993, which confirm that, linear model correlated well with the experimental data. The system temperature (Temp.), operation time (time) and the interaction between system temperature and time were statistically significant variables for LA concentration at alpha = 0.05.
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    Thermal-Acid Hydrolysis of Sisal Boles Juice for Lactic Acid Production
    (2018) Msuya, N; Katima, J.H.Y; Minja, R. J. A; Masanja, E; Temu, A.K
    The effect of reaction temperature, time and pH on the maximum total sugar concentration during thermal-acid hydrolysis of sisal boles juice was investigated. The Minitab software (V. 17) was used to design a 2n full factorial design for sisal juice hydrolysis and analyse the effects of the variables on the response. Thermal-acid hydrolysis can be carried out at a moderate temperature of 60°C with a concentrated hydrochloric acid at pH of one within a period of 30 minutes to achieve a sugar yield of 39%. The breakdown of complex sugars to simple sugars of sisal bole juice is basically a function of acid concentration in sugar solution. Lowering pH of the juice contributed to increase in hydrolysis rate. The use of ANOVA analyses gave evidence that linear, 2- way interactions and 3-way interactions of all the variables: temperature (60-100°C), time (30-60 min) and pH (1-5) significantly affected the sugar yield. This amount of sugar yield from sisal boles juice is higher than the yield of 26% which has been reported. The hydrolysed juice was also subjected into fermentation for lactic acid and results showed favourable LA yield was obtained with the recommended thermal-acid hydrolysis in this study.