Zegey, Adamu (Mr)Zeberga, Seifu2018-07-172023-11-102018-07-172023-11-102010-06http://etd.aau.edu.et/handle/12345678/8815Fruits and fruit products are the enigma of food in modern society. Fresh fruits are perishable and have limited shelf life. To prolong shelf life, various processing and preservation methods such as drying, chemical treatments and various packaging methods are used. Spray drying of mango and banana pulp into powder is a challenging operation, mainly due to heat sensitive and hygroscopic nature of the fruits. Identification of the optimum inlet temperature and flow rate is crucial for proper drying to produce powders using spray driers. This study was conducted using a laboratory scale mini spray dryer to develop mango and banana powders and evaluate their sensory qualities. The improved mango (Tommy) variety was obtained from Upper Awash Agroindustry Enterprise and the local Arbaminch mango and banana were purchased from the local market in Addis Ababa. The experiments on spray drying and product quality analysis were carried out in the Food Engineering laboratory of the Department of Chemical Engineering, Addis Ababa University. Laboratory analysis of the proximate composition was conducted at the Ethiopian Health and Nutrition Research Institute (EHNRI). The development of mango and banana powders involved: cleaning, peeling, stone removal, chopping, pulping, dilution, filtration and spray drying. Feed flow rate and inlet temperature were varied at 3.6 and 4.5 ml/min (12 and 15 % of pump rate) and 200,210°C for mango powder and 3.6 and 4.5 ml/min(12 and 15 % of pump rate) and 170,180°C for banana powder, respectively. Physico-chemical properties of the fruits were determined. The mango and banana powders were analyzed for bulk density, particle size, residual moisture content, soluble solids, protein content, fat content, crude fiber content and, vitamin C. Sensory evaluation was conducted for both mango and banana powders. The collected data were subjected to analysis of variance using statistical soft ware SPSS version 17. The inlet temperature and flow rate were found to have significant effect (P< 0.05) on the yield, moisture, solubility and bulk density of mango and banana powders. As inlet temperature increased from 2000 C to 210 0 C for mango pulp and from 170 0 C to 180 0C for banana pulp and flow rate from 3.6 and 4.5 ml/min(12 and 15 % 0f pump rate) , the mango and banana powder yield decreased 24.5 g to 20 g and from 12.5g to 10.35g ,respectively. Sensory evaluation results showed that 75% of the panelists preferred the mango powder produced at inlet temperature of 200oC and 3.6 ml/min flow rate(12% of pump rate), while xiii 62.5% of them preferred the banana powder manufactured at 170 oC and 3.6 ml/min flow rate(12% of pump rate). Processing of mango and banana fruits using spray dryer is capable of producing powder that retains nutritional values, colour, and aroma and is suitable for commercialization. This study clearly indicated that especially there is an opportunity for mango powder production in the country. Based on the findings, an economically feasible processing technology for mango powder production has been suggested. Key words: Banana; Mango Powder; Quality; Sensory Evaluation; Spray dryingenBanana; Mango Powder; Quality; Sensory Evaluation; Spray dryingThesis