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| dc.contributor.author | Berhanu, Regassa Jima | |
| dc.date.accessioned | 2024-02-01T10:22:47Z | |
| dc.date.available | 2024-02-01T10:22:47Z | |
| dc.date.issued | 2023-06 | |
| dc.identifier.uri | http://ir.bdu.edu.et/handle/123456789/15592 | |
| dc.description.abstract | Teff is a cereal grain which is used to make injera, a staple food of Ethiopians. Injera with appropriate quality and consistency is crucial that all consumers demand on the streamlined quality parameters. Because of inadequate process parameters, injera quality is usually a serious problem. Flour particle size and dough kneading time are among the factors that can affect injera quality. This research was aimed to investigate the effect of flour particle size and kneading time on functional, physicochemical, dough rheological property and injera quality. Tseday variety of teff grain was used for the study and milled into different particle sizes. The flour particle size was evaluated by passing through sieve size of 180µm, 355µm and 500µm. Flour particle size of fine (0-180µm), medium (181-355µm) and coarse (356-500µm) was obtained 30.68%, 42.54% and 25.31%, respectively. Mechanical dough kneader was used to knead the injera dough with 4, 8 and 12 minutes with constant and moderate kneading speed of #K 2 (164rpm). The physicochemical and functional properties of flour and microbial and sensory qualities of injera samples were analyzed using standard methods. Higher water and oil absorption capacity were observed in fine flour particle size (1.25g/g and 2.59g/g as compared to coarse flour particle sizes (1.08g/g and 1.77g/g, respectively). Fine particle size of teff flour had loosely packed structure and thus the bulk density of fine flour particle size is (0.68g/mL) lower than coarse flour particle size (0.77g/mL). The L* value of flour color was ranged from 75.08 to 81.02 from coarse to fine due to the presence of bran fractions in coarse flour. Observations from pasting properties revealed 1056, 1030, 968 and 1067 peak viscosity for fine, medium, coarse and control flour respectively. Whole teff flour showed significantly (p˂0.05) lower values of G'(400.23) and G"(246.84) and higher Tan d (0.54) than treatment flour samples. This indicated the mechanical rigidity of the dough which is preferred for quality injera. The proximate composition of treatment flour samples varied from 8.79-9.05% (moisture), 9.12-11.27% (protein), 2.54-3.00% (fat), 2.02-2.61% (ash), 1.92-3.31% (fiber) and 71.69-74.11% carbohydrate. Proximate composition of injera samples varied with different flour particle sizes and dough kneading times. Accordingly moisture, protein, fat, fiber, ash, carbohydrate and Total energy of all treatment samples ranges from 5.90-6.45%, 10.32-12.82%, 1.18-1.73%, 2.01-3.37%, 2.40-2.73% 73.68-77.66% and 356.81-364.25%, respectively. Significantly higher contents of phytochemicals and minerals were perceived on coarse flour particle size injera than fine due to the presence of higher concentration of grain's outer layers in coarse flour. The bacterial load of injera was detected in samples of injera made from fine flour that had been kneaded for 12 minutes on day five of storage with a value of 4.54log cfu/g Injera samples had a yeast/mold load that ranges from 1.77 to 5.08log cfu/g from day one to day five storage. The highest overall acceptability of injera by the panelist was formulated from fine flour particle size with 12 minute dough kneading time having the score of 4.66. In general, fine flour particle size with 12 minute dough kneading time resulted in desired nutritional and injera quality. Keywords: Injera quality, Kneading time, Particle size, Rheological property, Teff flour | en_US |
| dc.language.iso | en_US | en_US |
| dc.subject | Chemical and Food Engineering | en_US |
| dc.title | Effect of Teff Flour Particle Size and Kneading Time on Dough Rheological Property and Injera Quality | en_US |
| dc.type | Thesis | en_US |
