EVALUATION THE EFFECTS OF PUMPKIN SEED FLOUR ADDITION IN WHEAT FLOUR OF A STRONG QUALITY FOR BREAD MAKING ON BREAD QUALITY

The goal of this study was to investigate the addition of five different levels (control, 5%, 10%, 15% and 20%) of pumpkin seed flour (PSF) in wheat flour (WF) on bread quality. The chemical composition (moisture, protein, fat, ash and carbohydrates) and alpha-amylase activity of wheat-pumpkin seed composite flour was determined. The physical. characteristics (loaf volume, porosity, elasticity), in addition to crumb color, mechanical textural parameters, sensorial characteristics and microstructure were determined in the control sample and supplemented bread's. Principal component analysis was applied to show the relationship between physico-chemical parameters of wheat-pumpkin seed composite flour and bread characteristics. The results of chemical characteristics showed that PSF increased protein content, fat and ash of wheat-pumpkin composite flour, but decreased the moisture and carbohydrates content. Comparatively with the control sample, a increasing of alpha-amylase activity of composite flour was obtained at addition level of 5% and 10 % PFS in WF. The loaf volume, porosity and elasticity significant decreased with PSF addition higher than 10%, while the hardness increasing. With the increase level of PSF addition in WF the lightness of samples decreased, the textural parameters gumminess and chewiness increases and large cells can be highlight in crumb structure of bread. Overall, the results showed that wheat flour of a strong quality for bread making supplemented with 10% PSF was adequate to "produce bread with a good acceptability; improved nutritional quality and beneficial helth effects to consumers. Also, significant correlations. (p < 0.05) between physicochemical parameters of wheat-pumpkin seed composite flour, bread characteristics and overall acceptability.