Effect of Gum Arabic from Acacia Senegal Var. Kerensis as an Improver on Quality Properties of Wheat Flour Dough, Bread and Chapati

Abstract

Synthetic improvers have been used in the baking industry to simplify production process and improve product quality. However, there is increasing demand for natural ingredients as consumers are demanding for healthier products. Gum Arabic from Acacia senegal var. kerensis is one of the promising alternatives as it exhibits excellent water binding capacity. However, very little is reported on how it affects dough rheological properties and baked products. Therefore, the aim of this study was to determine the effect of using gum Arabic as an improver on dough, bread and Chapati. Wheat flour samples containing gum Arabic at 1%, 2% and 3%, plain wheat flour (negative control), commercial bread flour and commercial Chapati flour were analyzed for physicochemical properties, dough rheological properties and consequently used to make bread and Chapati. The products were analyzed for: loaf volume, textural properties, microbial quality and sensory properties. It was noted that gum Arabic significantly increased moisture (12.74-12.93), fibre (1.30-1.62), ash (0.84-1.06) and carbohydrate (70.65-71.16) content of the wheat flour but decreased the protein (12.15-12.39) and fat (1.48-1.95) content. There was also a significant increase in water holding capacity (0.97-1.37), oil holding capacity (1.17-1.49), emulsion capacity (47.53-52.37) and emulsion stability (43.46-51.22) of wheat flour. Gum Arabic significantly increased all the Farinograph properties except dough consistency (490-505BU) and all extensograph properties but significantly decreased all the Viscograph parameters apart from the pasting temperature (69.50-71.68ºC). Bread containing 2% gum Arabic recorded the highest specific volume (3.77). Addition of gum Arabic led to an increase in springiness (0.82-0.86), cohesiveness (0.51-0.59) and resilience (0.81-0.21) but a reduction in gumminess (438.66-1122.07) and chewiness (376.07-930.15). Chapati firmness (760.31-1081.33) significantly decreased with addition of gum Arabic. The microbial levels of total viable counts and yeasts and moulds in bread and Chapati samples were compliant with the Kenya Bureau of Standards guidelines on baked products. Principal component analysis indicated existence of 3 principal components in both bread and Chapati explaining 72.7% and 61.7% of the total variation respectively. Panelists preferred bread samples containing 2% gum Arabic and 3% in Chapati. Therefore, an optimal gum Arabic concentration of 2% in wheat flour dough is recommended in making of pan bread while that containing 3% recommended for making Chapati. These findings demonstrate the need to utilize gum arabic from Acacia Senegal var. kerensis in baking industries to aid in production of dough and high-quality baked products