Browsing by Author "Karteh, Sallu"

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The Influence of Gratering, Fermentation and Variety on the Physio-Chemical Quality of Cassava Starch
(Scientific Research Publishing, 2024) Karteh, Sallu
The study was conducted to determine the influence of gratering and fermentation parameters on the physicochemical quality of starch obtained from two cassava varieties in Sierra Leone (i.e., SLICASS 11 and SLICASS 6). Fresh cassava roots harvested from the Department of Agricultural Engineering were peeled, washed and grated before fermentation and starch extraction. Fermentation was carried out under separate aerobic and anaerobic conditions for a period of Seven days. Physicochemical analyses were conducted at the Postharvest Food and Bioprocess Engineering Laboratory of the Department of Agricultural and Bio-System Engineering, Njala University to determine the solubility, water absorption capacity and swelling power of starch extracts obtained from various experimental treatments. Fermentation method and duration had significant effects on the solubility, water absorption capacity (WAC) and swelling power (SP) of starch extracts. Maximum solubility and WAC were recorded on the fifth day, for both cassava varieties tested, with apparent significant difference resulting from the two gratering bands (i.e., with 1.5-inch nail hole and 4-inch nail hole sizes, respectively). While swelling power increased consistently with temperature for starch obtained from SLICASS-11 variety, an irregular pattern was observed for SLICASS-6 variety. A multiple correlation analysis proposes a significant and weak correlation between temperature, WAC (+0.150) and swelling power (+0.048). Also multiple correlation analyses suggest a significant correlation between fermentation period, the functional properties of starch extracts obtained from both fermentation methods and cassava varieties (i.e., solubility (−0.226), water absorption capacity (+0.301) and swelling power (+0.329)).
The Influence of Processing Parameters on the Physical Quality of Garri
(Science Publishing Group, 2025-01-24) Karteh, Sallu
Fermentation and dewatering of cassava mash are critical stages in processing of Garri in Sierra Leone and many other West African countries. This study examines the effect of grating band and dewatering pressure on the quality of Garri obtained from three improved cassava varietiesTR-0031, TR-01229 and TR-983, obtained from Njala Agricultural Research Centre, Sierra Leone Agricultural Research Institute (NARC, SLARI) using two locally made grating bands (4-inch nail size and 1.5-inch nail size). Five kilograms (5kg) of cassava mash was dewatered at pressures of 1422.33psi, 1066.748psi and 711.165psi. The resulting dewatered mash was roasted to obtain Garri. Samples of the Garri was used to conduct analysis for swelling index and particle size distribution. Data recorded was analyzed using Microsoft excel. Key findings: Water discharged by the different Pressing Pressure, pressure 1422.33psi discharged 1.42kg in four hours of pressing, pressure 1066.748psi discharge 1.20kg and pressure 711.165psi discharged 1.08kg. The swelling index for grating band 4” obtained a maximum of 57% and band 1.5” of 43% for variety TR-01229. On average grating band 4” swelled to a pick of 54.3% and band 1.5” obtained 45.7%. The statistical analysis conducted between varieties (TR-0983, TR-0031 and TR-1229) at 95% level of probability shows that no statistically significant difference of swelling index between varieties with p-value of 0.482185. For particle size distribution (PSD) maximum Garri retention was obtained by sieve 2 of 44% and minimum of 8% for sieve 5. A Pearson correlation shows a weak negative relationship (-0.709) between grating band and swelling index. The study leads to the conclusion that the nature of grating bands and magnitude of dewatering pressure are important factors in determining PSD and swelling power, which are key quality factors of Garri processing in Sierra Leone.