Drying kinetics of driedinjera(dirkosh) using a mixed-mode solar dryer

Abstract

Injera is a staple food for Ethiopians both in the country and abroad. Injera has high nutritional value as it is reach in fibre and other nutrients most importantly it is gluten free. Dried injera (dirkosh) is mostly preserved using open sun drying. But there is no study conducted to improve the drying process and evaluate dried injera (dirksoh) for its drying kinetics and performance of the solar dryer. This is the first attempt to formulate the drying kinetics of dried injera. Thus, a mixed mode natural convection solar dryer was designed, manufactured and tested using injera (dirkosh) in Addis Ababa, Ethiopia. The test result indicated that the drying efficiency and overall drying rate were 17.7% and 3.69 × 10 −5 kg/s, respectively. The moisture content of injera was reduced from 65.5% to 12% in wet basis in 4 h in the solar dryer. Statistical analyses of the result have shown that Midilli and Verma as a best fit models with the highest value of the correlation coefficient (R 2 ) and the lowest values of reduced chi-square (χ 2 ) and root mean square error (RMSE). Finally, it was concluded that solar drying of injera could be a feasible method for preserving and maintaining the quality of dried injera (dirkosh) with a minimum cost.

Simulation of mixed-mode solar dryer with vertical air distribution channel

“…All this technical specifications are extracted from previous works of Sileshi et al. [ 7 ] which are used as data input for the present work.

Figure 1 Schematic diagram showing the dryer with air distribution system [ 7 ].

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“…[ 7 ] which are used as data input for the present work.

Figure 1 Schematic diagram showing the dryer with air distribution system [ 7 ].

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“…Solar drying of injera helps to minimize the drawbacks of the traditional dirkosh production. Moreover, the solar radiation potential of Ethiopia encourages application of solar dryers [ 7 ].…”

“…The experimental results which were used for validation were extracted from the previous works of Sileshi et al. [ 7 ].…”

Thermal performance assessment of a passive mixed-mode solar dryer

“…Humans still employ the easiest and cheapest technique of drying in the open air, but it is not scienti cally regulated because weather conditions change during the day and night, resulting in lower food quality and standards. (Bhardwaj, Kumar, & Chauhan, 2019;Sileshi, Hassen, & Adem, 2021). The world's concern is to reduce food shortages by limiting food spoilage (Amare, Abay, Tiberti, & Chamberlin, 2021;Benyam, Soma, & Fraser, 2021;Lelea, Garbaba, Guluma, & Hensel, 2022).…”