Comparison of bread making properties of composite flours from kernels of roasted and boiled African breadfruit (Treculia africana decne) seeds

The effect of blending wheat flour with kernel flour from roasted and boiled African breadfruit (Treculia africana Dece) seeds at levels of 0 - 20% on rheological properties of dough, baking quality, nutritional properties and acceptability of bread was investigated. Rheological properties of dough which included resistance to extension (R), extensibility (E) and mechanical work for deformation (W) were studied using a Chopin alveograph. Bread loaves were prepared using the straight-dough procedure and evaluated for loaf volume, loaf weight and sensory properties. Protein quality was evaluated using weanling male albino rats fed composite bread diets, which were formulated to supply 10% protein, with casein diet as a control. There were no significant (P>0.05) differences between alveograph values obtained for R, E and W in blends containing 0 (100% wheat flour) and 5 to 10% breadfruit kernel flour from roasted and boiled seeds. With up to 10% substitution of wheat flour with kernel flour from roasted and boiled breadfruit seeds, bread loaves had acceptable crumb colour, crumb texture and loaf volume comparable to 100% wheat flour bread. Bread diets formulated with 10% breadfruit kernel flour from boiled seeds showed significantly (P<0.05) higher values for protein efficiency ratio, net protein ratio, apparent and true digestibilities than diets formulated with 10% roasted breadfruit kernel flour and 100% wheat flour bread, suggesting that boiling was more effective than roasting in improving the nutritional value of breadfruit - substituted composite breads.