Influence of Enzymatic Treatments on the Rheological and Pasting behaviors of Wheat Flour and Its Impact on Pan Bread Staling

Document Type : Original Article

Authors

Food Science Dept., Fac., Agric., Ain Shams Univ., Cairo, Egypt.

Abstract

Bread freshness is rather short during storage, owing to several complex physicochemical alterations that occur, which are collectively referred to as staling, that cause it to gradually lose its pleasant aroma and the crispiness of its crust. The response of different concentrations of fungal β-glucanase (BG) and maltogenic α-amylase (MAA) on extensograph parameters of medium-strength flour (MSF) contained fixed levels of fungal α-amylase, glucose oxidase, phospholipase, and ascorbic acid, was studied by the three-dimension polynomial quaternary model compared with strong flour (SF) for predicting the extensogram parameters. The optimum predicting concentrations were verified by using applied extensograph trials and then manufacturing pan bread. Proximate chemical composition and physicochemical characteristics for MSF and SF were studied., also, the effect of enzymatic treatments on pasting behavior was studied. Pan bread was evaluated for physical, texture, and sensory characteristics. The optimal extensograph parameters were selected at predicted MAA (0.29 U/g) and fungal BG (0.04 U/g) levels. MAA showed a clear impact on most pasting parameters by decreasing peak viscosity. Accordingly, the treatment of wheat flour by mixture enzymes (0.29 U/g MAA + 0.04 U/g BG) showed higher impacts. Mixed enzyme-treated bread (0.29 U/g MAA + 0.04 U/g BG) had the greatest effect in reducing hardness after 72 hrs. Pan bread sample that was prepared using treated MSF had significant (P ≤ 0.05) crumb softness, crumb folding, and mouthfeel scores compared to the control. Generally, MAA and BG significantly showed higher bread freshness than untreated bread.

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