Optimization of processing parameters for chickpea shiro flour using response surface methodology

Chickpea shiro flour is widely used across both rural and urban areas of Ethiopia to prepare shiro-wot, a traditional stew typically consumed with injera. While the core processing steps, soaking and roasting, are consistently applied in traditional practice, key parameters such as soaking duration, roasting temperature, and roasting time have not been systematically optimized. This study aimed to optimize processing parameters like soaking time, roasting temperature, and roasting duration to produce high-quality chickpea shiro flour using response surface methodology. The effects of soaking time (25–112 min), roasting temperature (165.9–334.1 °C), and roasting duration (1.59–18.41 min) were evaluated with respect to dehulling efficiency, functional attributes, proximate composition, color, and consumer acceptability. Statistical modeling and ANOVA demonstrated that all three parameters significantly (p < 0.05) influenced critical quality parameters. Dehulling efficiency, degree of dehulling, split yield, and broken grain ranged 29.91%–70.50%, 6.36%–14.23%, 14.68%–45.91%, and 2.04%–10.04%, respectively. Protein (22.15%–25.43%) and fat (10.12%–16.37%) increased with interaction intensity, while carbohydrates declined (53.18%–46.72%). Ash (2.10%–3.01%) and fiber (3.87%–4.68%) rose slightly, with bulk density (0.62–0.74 g/cm3) and water absorption capacity (2.11–2.83 g/g) also increasing moderately. Aroma (1.13–4.95), texture (1.73–4.46), color (1.10–4.88), taste (1.01–4.89), and overall acceptability (1.01–4.98) were all negatively impacted by prolonged roasting, whereas moderate soaking and short-term, high-temperature roasting increased the sensory acceptability of chickpea shiro flour. The optimal conditions were 90 min of soaking, 292.906 °C roasting, and 6.84 min of roasting resulted in the highest overall acceptability score, efficient dehulling, desirable color, and balanced functional properties. These findings highlight the importance of applying moderate roasting temperatures with shorter roasting durations to achieve a balance between flavor development, nutrient preservation, and structural integrity. The significance of this study is that it enables the development of optimized processing conditions for chickpea shiro flour that improve nutritional quality, functional properties, and product consistency, thereby supporting food security, value addition of local legumes, and the scalability of culturally rooted plant-based foods for global markets.