Physicochemical, nutritional composition, cooking, and functional properties of newly introduced low land rice varieties grown in Ethiopia

Abstract

In Ethiopia, the cultivation of lowland rice varieties is recently introduced. However, the physicochemical and functional characteristics of these varieties are not reported. Therefore, this study was conducted to determine the physicochemical properties, proximate and mineral compositions, and cooking and functional properties of the six rice varieties (Demozie, Ediget, FOFIFA, Gumara, Hiber, and X-jigna) cultivated in two locations (Fogera and Pawe). Grain length, length-breadth (L/B) ratio, and thousand kernel weights (TKW) were within the ranges 5.16–7.19 mm, 1.81–2.6 mm, and 22.13–29.43 g, respectively. FOFIFA from Pawe was characterized by the highest values for grain length (7.19 mm) and TKW (29.43 g). The crude protein, ash, and fiber contents were within the rages of 5.56–1.02, 0.47–1.58, and 2.16–3.66%, respectively. Varieties from Pawe contained significantly higher protein compared with Fogera. X-jigna from Pawe had the highest amylose content (26.57%) and alkaline spread value (ASV, 7.1), as well as the lowest for gelatinization temperature (64.33 °C) compared to others. The minimum cooking time ranged from 7.67 min for Hiber to 48.0 min for Gumara – both from Pawe. Gruel solid loss, water uptake ratio, and kernel elongation varied at 1.16–2.55, 1.34–1.46, and 1.04–1.17%. The calcium, zinc, iron, magnesium, and manganese contents were within the ranges of 0.60–19.60, 1.49–3.56, 1.21–9.26, 63.18–120.88, and 1.42–4.02 mg/ 100 g, respectively. Water absorption (WAI) and water solubility (WSI) indices were within the ranges of 6.03–6.20 g/g and 2.49–3.61 g/g, respectively. Gumara and Fogera had the highest (13.91) a* (redness) color value compared to others. All of the quality characteristics considered in this investigation were markedly influenced (p < 0.01) by the variety and growing location. It could be concluded that the use of different rice varieties cultivated at different locations yielded products with significantly different rice quality attributes.