Exploring the Use of Purple Corn Cob Flour as a New Fiber Source in Pan Bread Improved by Commercial Hemicellulases

Abstract

Bread stands out for its versatility and accessibility, appealing to individuals across various ages and social classes. Consequently, it presents an attractive opportunity for incorporating ingredients that offer health benefits to consumers. In this context, the current study aimed to evaluate the technological properties of sandwich bread (specific volume, water activity, moisture, instrumental color, and texture) prepared with a partial substitution (5% w/w) of wheat flour (WF) with purple corn cob flour (PCF) (F1), along with the addition of hemicellulolytic enzymes of fungal (F2) and bacterial (F3) origin. The enzymatic action had a positive impact (<em>P </em>< 0.05) on the specific volume of the samples (F2: 4.17 ± 0.16 cm³/g and F3: 4.52 ± 0.02 cm³/g) compared to the standard (3.78 ± 0.07 cm³/g), which was reflected in the instrumental texture parameters. Parameters such as firmness, hardness, gumminess, and grittiness were less pronounced in the samples with enzyme addition compared to the control. The samples did not differ statistically regarding water activity and instrumental color parameters (<em>a*</em> and <em>b*</em>). However, enzymatic action reduced the crumb's brightness (<em>L*</em>) in both cases, which was attributed to the release of reducing sugars. The values of color variance (ΔE) were less than 5, indicating that untrained individuals cannot differentiate between the sample's colors. Thus, the incorporation of hemicellulolytic enzymes in sandwich bread with partial substitution of WF by PCF improves the technological properties of the finished product, adding value to an agro-industrial co-product.