Effect of replacing wheat flour with pumpkin powder on the batter viscosity and the physicochemical and sensory properties of pancakes

Introduction: The food industry currently faces the dual challenge of meeting the nutritional needs of a growing population while responding to consumer demand for functional foods. Bakery products, as widely consumed foods, provide an ideal platform for nutritional enrichment. Utilizing unconventional, bioactive-rich ingredients such as fruit and vegetable powders offers an innovative strategy to enhance health benefits and diversify products (Abedfar & Sadeghi, 2016; Salehi & Aghajanzadeh, 2020; Sarmasti et al., 2023; Adesunmibo et al., 2025).
Pumpkin (Cucurbita moschata) is rich in carotenoids (especially beta-carotene), phenolic compounds, vitamins, minerals, and dietary fiber, making it a promising ingredient for food enrichment. These compounds not only provide antioxidant activity but also influence sensory and physicochemical properties of the final product (Rakcejeva et al., 2011; Hosseini Ghaboos et al., 2018). Previous studies have shown that adding pumpkin powder can significantly increase moisture, ash, and mineral content in cakes, while improving sensory attributes and consumer acceptance (Jalali et al., 2018; Hosseini Ghaboos et al., 2018; Khormali et al., 2021).
Pancakes, as a popular bakery product, can serve as a suitable carrier for these bioactive compounds (Chen et al., 2022; Vejdanivahid & Salehi, 2025). However, partial substitution of wheat flour with pumpkin powder introduces technical challenges, affecting dough rheology, water balance, starch–protein interactions, and gluten network formation. These changes, in turn, influence physicochemical properties such as color, texture, moisture, and bioactive content, which ultimately affect key sensory attributes, including appearance, aroma, taste, texture, and overall acceptability (Salehi & Aghajanzadeh, 2020).
Despite scattered studies on pumpkin powder in bakery products, there is a lack of comprehensive research simultaneously evaluating the effects of increasing substitution levels on dough rheology, final product physicochemical properties, and sensory acceptance. This study aims to fill this gap by investigating the impact of replacing wheat flour with 0, 10, 20, 30, and 40% pumpkin powder on pancake dough rheology, physicochemical properties (color, texture, phenolic content, antioxidant activity), and sensory characteristics (appearance, aroma, taste, texture, overall acceptability). It is hypothesized that pumpkin powder will enhance nutritional and antioxidant properties, induce measurable changes in dough and product properties, and, at optimal levels, produce pancakes with high sensory acceptability, paving the way for industrial production of enriched, healthy, and consumer-friendly bakery products.
Material and methods:
Materials: Wheat flour (Zar Macaroni, Iran), vanilla (Hamishk, Iran), baking powder (Myofl, Iran), sugar (Zamen, Iran), full-fat pasteurized milk (3.4% fat, Damdaran, Iran), fresh eggs (Telavang, Iran), sunflower oil (Tabiat, Iran), and fresh pumpkin were sourced locally in Hamadan, Iran. Chemical reagents included Folin–Ciocalteu reagent, sodium carbonate, gallic acid, DPPH, and ethanol.
Pumpkin Powder Preparation: Fresh pumpkin was washed, sliced thinly, dried at 70°C for 100 min, and ground into powder using an industrial mill.
Pancake Preparation: An optimized formulation was used, with gradual substitution of wheat flour with pumpkin powder at 0, 10, 20, 30, and 40%. Egg whites were whipped to form a stable foam, yolks were emulsified with oil, and dry ingredients were gradually incorporated. The batter rested for 10 min at room temperature before cooking (25 g per pancake at 180-190 °C).
Batter viscosity: In this study, after preparing the pumpkin powder, the pancake batter was formulated according to an optimized recipe, and the different substitution levels were applied. Apparent viscosity of pancake batter measured using a rotational viscometer at 5, 10, and 15 rpm.
Physicochemical properties: Moisture, ash, pH, titratable acidity, baking loss, volume, density, phenolic content (Folin–Ciocalteu), and antioxidant activity (DPPH assay).
Color and texture: Color parameters obtained via image analysis (RGB to L*, a*, b*), crust hardness assessed by penetration test.
Sensory evaluation: Conducted with 20 trained panelists for appearance, aroma, taste, texture, and overall acceptability.
Statistical Analysis: All experiments were conducted in triplicate. Data were analyzed using one-way ANOVA, and mean comparisons were performed with Duncan’s multiple range test at p<0.05.
Results and discussion:
Batter viscosity: The addition of pumpkin powder significantly increased the apparent viscosity of pancake batter at all shear rates (5, 10, and 15 rpm). The effect was dose-dependent, with the 40% substitution showing the highest viscosity. This increase is attributed to the high water-holding capacity and fibrous nature of pumpkin powder, which strengthens the batter network. The batter exhibited pseudoplastic behavior over 120 s, with higher substitution levels showing greater rheological stability.
Color parameters: Pumpkin powder significantly affected batter color, decreasing lightness (L*) and increasing redness (a*) and yellowness (b*), reflecting the natural carotenoid content. Lightness decreased from 89.1 (control) to 81.2 (40%), redness increased, and yellowness rose from 32.5 to 71.2. These changes may influence consumer perception, as color is a key quality indicator.
Physical properties: Increased pumpkin powder led to higher pancake weight (23.2 g to 24.5 g), reduced baking loss (7.2% to 1.2%), increased volume (20 cm³ to 23.7 cm³), and decreased density (1158 kg/m³ to 1031 kg/m³). These results indicate better moisture retention, lighter texture, and improved structural properties.
Moisture, ash, pH, and acidity: Moisture and ash content increased significantly with higher substitution, enhancing nutritional value. pH decreased (8.15 to 6.10) while acidity increased (0.30% to 0.63%), reflecting the presence of natural acids and phenolic compounds in pumpkin powder.
Phenolic content and antioxidant activity: Total phenolic content and antioxidant capacity rose with substitution, from 967.1 to 1659.8 µgGAE/g and 35.4% to 79.3%, respectively, demonstrating pumpkin powder as a rich source of bioactive compounds.
Crust hardness: Pancakes became progressively softer with higher pumpkin levels, likely due to the formation of a hydrocolloidal matrix and reduced gluten content.
Sensory evaluation: While appearance scores decreased due to darker color, aroma, taste, texture, and overall acceptability improved with higher pumpkin levels. The 40% substitution achieved the highest overall acceptance, indicating strong potential for consumer-preferred fortified products.
Conclusion: Partial replacement of wheat flour with pumpkin powder effectively enhances the nutritional and functional properties of pancakes. Increasing substitution up to 40% improved batter viscosity, product volume, moisture, and texture, while significantly raising total phenolic content and antioxidant activity. Although darker color slightly reduced visual appeal, aroma, taste, and texture improved, resulting in the highest overall acceptability for the 40% sample. These findings indicate that pumpkin powder can produce health-promoting pancakes with desirable texture and strong consumer acceptance.