Dough rheology and baking properties of bread from wheat/ hybrid banana composite flour

Abstract

In spite of high productivity and good agronomic adoptability of hybrid cooking bananas, they have undesirable sensory characteristics hence low consumer acceptability. This study aimed at evaluating the effect of partial substitution of wheat with hybrid cooking banana flour on the dough rheology and baking properties of composite bread. Five hybrid banana varieties; M30, M9, N15, N21 and N23 were used in this study. Bananas at green maturity were processed into flour and blended with wheat to make various composite flours (10/90, 20/80, 30/70 and 40/60%). Unblended wheat flour (100%) was used as a control. The different blends were then used to make the wheat composite bread using the straight-dough method. Rheological properties of the composite dough were analyzed using a consistograph (water absorption capacity and maximum pressure), alveograph (peak height, extensibility and baking strength) and farinograph (mixing tolerance index and development time). Textural properties (hardness, springiness, cohesiveness) were determined using the texture analyzer while sensory attributes were investigated using the 9-point hedonic scale. The dough rheology values reported in this study ranged from; water absorption capacity (47.25% to 54.45%), maximum pressure (1315.50 mbar to 2911.50 mbar), peak height (82.50 mm to 151.50 mm), extensibility (19.50 mm to 113.50 mm), baking strength (67.50 J to 244.50 J), development time (1.10 min to 5.40 min) and mixing tolerance index (86.00 BU to 175.50 BU). Hardness increased with increasing banana flour percentage inclusions, ranging from 2.09 N to 4.39 N. Springiness had no specific trend across the hybrids, but ranged from 0.35 to 0.80. Cohesiveness decreased with an increase in banana flour inclusion levels, ranging from 0.05 to 0.56. Sensory evaluation results showed a decrease in panel acceptability of the composite bread as the percentage inclusion of hybrid banana flour increased. The best scores for the sensory parameters evaluated were recorded at 10% inclusions of M30. Inclusion of hybrid banana flour up to 10% for all varieties studied as well as 20% inclusions for M30, N21 and N15 was comparable to 100% wheat flour. It is therefore recommended to use up to 20% inclusion levels of hybrid cooking banana flour from M30, N21 and N15 in preparation of hybrid banana / wheat composite bread.