Anuradha Jabasingh (PhD)Lubaba Moshe2023-12-142023-12-142023-10http://etd.aau.edu.et/handle/123456789/972Gum Arabic, or acacia gum, is the resin exuded by Acacia Senegal trees. It also has several industrial applications. But these, natural gum Arabic exudates are contaminated by sand, dirt, insects, pieces of bark and leaves, bacteria and so forth. This condition makes the gum exudes to be unsuitable for the immediate use. Therefore, finding the purification process of gum Arabic is the first and the most important step. This mechanism improves the quality of the product and makes direct immediate use of acacia gum in the industry. The core objective of this research work was to produce purified, dried, instant gum Arabic powder and develop optimization of the freeze drying operating conditions. Finally characterization of the powder was carried out and yield was determined. To conduct this study, impurities of gum exudates were removed by three major separation processes. This is carried out by dry cleaning, aqueous solution cleaning and freeze drying process respectively. In this study, different concentrations of dissolved gum Arabic solution and drying temperature of 25%w/v to 33.33%w/v and -50°C to -30°C as maximum and minimum values were used respectively. Optimization for these drying parameters was carried out by the central composite design, using the Response Surface Methodology (Design experiment software version 11). During the experiment, it was observed that the acacia gum yield at different runs ranged from 96.35g to 214.1g and the moisture content ranged from 6.07% to 13.9%. An optimum acacia gum yield of 136.12g and minimum moisture content 10.16% were observed at -31.8°C temperature and 33.33% (w/v) feed solution concentration. The two main factors considered for this research study, namely feedstock concentration and drying temperature had a statistically significant effect (p<0.05) on both responses named the powder yield and moisture content. After the synthesis, the product (acacia gum powder) was characterized using FTIR spectroscopy, NMR Spectroscopy, TGA Analysis and DSC Thermogravimetric Analysis.en-USGum Arabic powder, Freeze drying, Moisture content, Yield, Separation process, Response surface methodology, Central Composite Design, OptimizationThesis