Effect of carrot flour addition on the texture profiles and β-carotene retention of donuts

Abstract

This study aimed to investigate the effects of carrot flour substitution on the textural and sensory properties of donuts. Carrot flour was incorporated at substitution levels of 0%, 10%, 20%, and 30% in the donut formulation. Texture characteristics, including hardness of the dough and donut (crumb and crust) and crumb porosity, were evaluated using texture analyzer. A total of 150 participants (mean age 22.5 ± 5.6-years-old, 61% female and 39% male) assessed the samples using a 5-point Just-About-Right (JAR) scale for color, tangy aroma, bitter taste, and texture, followed by overall liking ratings. The results showed that the hardness of both dough and donuts increased significantly with higher levels of carrot flour substitution (p< 0.001). Donuts containing greater amounts of carrot flour exhibited a significantly firmer crumb and crust, along with smaller pore sizes in the crumb structure (p< 0.001). Sensory evaluation revealed that color (p= 0.001) and tangy aroma (p< 0.001) affected consumer liking even at the lowest substitution level (10%), whereas bitterness start to influence liking at 30% level (p< 0.001). Texture consistently impacted liking across all samples, indicating its substantial attribute in donut acceptability. Despite the changes in texture and sensory perception, carrot flour addition was significantly increased the β-carotene content, from 2.54 mg/kg (0%) to 17.8 mg/kg (30%), representing nearly a tenfold enhancement (p< 0.001).