Enhanced Cassava Flour Quality to Improve the Cassava Bread by Attibutes Yeast Fermentation

Cassava is rich in starch and serves as a food staple in tropical and subtropical regions worldwide. However, cassava contains hydrocyanic acid, which can be harmful to human health in high concentrations. Proper processing methods, such as soaking, fermentation, or cooking, are typically employed to reduce cyanide levels to safe limits (< 10 mg HCN/kg), where it may even exhibit antioxidant properties. Without adequate processing, excessive consumption of cassava with high cyanogenic content may pose health risks. Yeast fermentation improves the nutritional and functional properties of cassava flour, improves protein content, reduces hydrocyanic acid content, increases flavor compounds, and alters starch particle size, viscosity, and relative crystallinity. These changes contribute to better dough elasticity, increased nutrient bioavailability, and overall quality improvement in cassava bread. The results demonstrated that the nutrition of fermented cassava flour was enhanced, with the protein content increasing from 0.89 ± 0.08 g/100 g to 3.86 ± 0.12 g/100 g and the hydrocyanic acid content decreasing from 32.64 ± 0.67 mg/kg to 7.40 ± 0.22 mg/kg. Fermentation significantly altered the volatile profile of cassava flour, increasing both the diversity and concentration of flavor compounds. GC-MS analysis detected 17 volatile components in fermented cassava flour, compared to only 12 in unfermented flour (control). Key flavor-active compounds-including 2-methyl-1-butanol (malty), phenethyl alcohol (floral), and ethyl linoleate (fruity)-were notably enhanced, contributing to the improved aroma of fermented cassava flour. The findings indicated that yeast fermentation enhanced cassava flour's nutrition (protein) and flavor compounds and improved its processing characteristics. Fermentation also modified the physicochemical properties of cassava flour, including reduced particle size, lower paste viscosity, and a more ordered crystalline structure-changes that enhance its processing stability (e.g., resistance to retrogradation and improved dough handling). When incorporated into bread formulations, 20% fermented cassava flour yielded superior textural properties (e.g., reduced hardness, higher elasticity) and higher sensory scores (appearance, flavor, and overall acceptability) compared to cassava breads and very close to wheat bread.