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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/2888

Title: EFFECT OF PROCESSING ON SOME QUALITY ATTRIBUTES OF MANGO (Mangifera indica) FRUIT LEATHER
Authors: BINYAM, TESHOME
Advisors: Mr. Adamu Zegeye
Keywords: Leather
Quality
Processing
Mango
Copyright: May-2010
Date Added: 10-May-2012
Publisher: AAU
Abstract: The seasonal production of mango fruit in Ethiopia has to be considered as an opportunity for the utilization of the fruit. The objective of this research was to study the influence of processing on some quality attributes of mango fruit leather developed from two fruit varieties namely, Keitt (local mango) and Tommy Atkins (export standard mango). First, 3.2 kg of mango fruit from both varieties were allocated for the process to be peeled, cut, sliced into pieces and stones removed. Mango puree was made using a food processor to obtain 1.65 kg puree. It was put in a beaker and covered with aluminum foil and then inserted into a water bath fitted with thermostat to control the temperature. Additional ingredients of Honey, Ginger and Lemon Juice were added and mixed. In order to cook and shorten the drying time, the mixture was heated at three different temperatures, 600C, 700C and 800C whilst being continuously stirred. The puree mixture was poured onto the trays to an approximate thickness of 0.64 cm. The trays containing the puree were placed in a drying oven. Oven drying was conducted for 8 h and finally 0.52 kg of mango leather was obtained. Drying experiment was also undertaken using convective hot air dryer to minimize the drying time of the fruit leather using a similar procedure. A minimum drying time of 4 h was achieved in a convective hot air dryer for Keitt mango fruit leather at 800C with 0.4 g/cm2 puree load. The major factors considered to have an effect on the leather quality were drying temperatures of 600C, 700C and 800C, puree load of 0.4 g/cm2 and 0.6 g/cm2 and fruit variety. The developed leather underwent physico-chemical, textural, microbiological and sensory analysis. The data obtained was analyzed using SPSS version 17 statistical software. The result indicated that 70.3 % of moisture loss resulted in the drying process. The viscosity of the mango puree was found to be dependent on heating temperature. As the temperature increased, the viscosity of the puree first decreased and then increased within the range of temperature 25.1 to 70.0 0C. The texture analysis result of the final mango leather showed that 4 sheets and 5 sheets of leather with 5mm and 6mm thickness, respectively, were found to be suitable for a single bite. The results of the proximate analysis for both varieties of mango fruit leather indicated that the processing affected the nutritional composition of the fruit leather. The vitamin C content was also found to be dependent on all drying temperature, puree load and fruit variety. The vitamin C content of the Keitt mango leather (26.93%) is greater than that of Tommy Atkins mango leather (22.71%). When compared to the fresh puree mix, the Keitt mango leather is decreased by 39.66% and that of the Tommy Atkins mango leather is decreased by 57.82%. The result of microbiological analysis for yeast, coliform, x fecal coliform, E.coli, and Shigella species was found to be safe (<1X104) and S.coccus and Salmonella species were not isolated for both varieties of mango leathers processed at 600C and 0.6 g/cm2 puree load. The Tommy Atkins mango leathers dried at 60 and 700C with 0.4 and 0.6 g/cm2 puree loads were preferred by panelists (P<0.05). The project generally covered the process and analysis of mango fruit leather and its development at a laboratory scale. Accordingly, an economically feasible production technology has been suggested.
URI: http://hdl.handle.net/123456789/2888
Appears in:Thesis - Food Engineering

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