Roasted Barley Foods: Processing and Varietal Differences Affecting Kolo and Tihni, Traditional Grain Products in Northern Ethiopia Kolo and tihni are roasted barley grain products commonly consumed and increasingly marketed in Ethiopia; however, very limited research has been done on their processing and nutritional value. This study describes the impact of kolo and tihni processing on different food quality parameters of eight barley varieties. Roasting was done at 140°C for tihni and kolo with different roasting times; results for roasted samples were compared with those for nonroasted samples. Significant differences were observed in total starch, β-glucans, kernel hardness, and thousand kernel weight among the nonroasted samples but generally not after roasting, except in the case of β-glucans for tihni processed samples. Damaged starch, water absorption capacity (WAC), water solubility index (WSI), and starch pasting properties were significantly different among the nonroasted and roasted samples. Roasting increased average damaged starch from the nonroasted mean of 3.0% to the roasted (tihni and kolo) mean of 12.4%. Average WAC increased from nonroasted (1.9 g) to roasted (4.2 g) sample means, and WSI showed inconsistent effects. Roasting significantly decreased starch pasting properties and flour whiteness (L*), whereas flour redness (a*) and yellowness (b*) increased. Mean insoluble β-glucan decreased by 21.5% in tihni and 36.7% in kolo, whereas soluble β-glucan increased by 11.7% in kolo samples, suggesting that roasting affected β-glucan solubility. Because soluble β-glucan is thought to have health-promoting benefits, roasting should be optimized to increase the soluble β-glucan content of kolo and tihni barley food products. The potential of roasted barley as a “healthy snack” is discussed. |