A THESIS SUBMITTED TO THE DEPARTMENT OF HORTICULTURE, COLLEGE OF AGRICULTURAL SCIENCE, SCHOOL OF POSTGRADUATE STUDIES ARBA MINCH UNIVERSTITY

Abstract

Mango (Mangifera indica L.) is one of the most important fruits harvested in the world. In Ethiopia Post-harvest loss negatively affects both the economy and nutrition of individuals. Study was undertaken to develop acceptable fruit bars from the low-quality mangoes. The fruit was collected from Chano Mille Kebele of Arba Minch Zuria woreda. Fruit was washed, sliced, autoclaved and pulped. Sugar and cassava flour at 5% and 3 % and lemon juice were added respectively, to the pulp. The pulp was heated to 80 0C and then cooled to about 55-600 C. To half of the pulp samples potassium metabisulphite at 1500 ppm was added. The two lots of pulp (KMS treated and untreated) were further divided into two sublots each. The sun drying and solar chamber drying were used for preparation of fruit bars. The pulp samples were spread on stainless steel trays at 0.841 grams/cm2 and placed in sun and solar chamber dryer for drying. Drying temperatures were recorded on hourly basis. The pulp samples were dried to a moisture content of 12.84 to 13.84 %. The mango bar samples were vacuum packed and stored at room temperature. Storage period effects was conducted on monthly basis for three months. The result of the study showed that in solar dryer only 13 hours were required for drying the mango bar samples whereas for sun drying 16 hours were needed. Mango Bar prepared from KMS treated pulps and dried in solar dryer showed the highest values of vitamin C (51.33 mg/100g) and beta carotene (3227.85 μg/100 g). These samples bar scored highest scores for taste, colour and overall acceptability even up to three months storage period and had the lowest microbial load. Carbohydrate and Reducing sugars in the main effect, TSS and fiber content in three interaction effect have shown increasing trend during storage duration. Moisture content and non-reducing sugar in main effect, ash in two interaction effect methods of KMS treatment with storage duration, vitamin C in two interaction effect of drying method and storage duration and protein, pH value and beta carotene in three interaction showed significant (p≤ 0.5) reduction during storage. Among all the treatments the mango bar prepared from KMS treated pulp and dried in solar dryer ranked best for its quality attributes including storage life. These bars were may safe for consumption even after three months of storage at room temperature, while sun-dried bar were not advisable to be consumed after three months storage.