Effect of Transglutaminase Enzyme on the Preparation and Quality of Gluten Free Composite Flour Bread
رجاء حميد طه الصادق , مها فضل محمد البلولة
كلية الدراسات العليا-جامعة السودان للعلوم والتكنولوجيا · السودان
The aim of this work was to determine the impact of addingtransglutaminase (TGase), to sorghum, corn and rice composite flour on thephysicochemical and sensory properties of gluten-free breads. Samples wereproduced from flour containing of 0.0 (A), 5.0 (B), 10.0 (C) and 15.0 (D) μgTGase /g of protien.The chemical composition of gluten free bread flour has moisture, ash, fat,fiber, protein and carbohydrate contents of 9.66, 1.93, 2.09, 7.28, 11.35 and 67.60% respectively. Also the gluten free mixture was found to be good in magnesium(17.04 mg), calcium (12.73 mg) and low in potassium (0.519 mg) and phosphorus(0.658 mg) while it was free of Iron.The samples were weighed in the following portions to prepare gluten freebread: White rice flour 34.5 %, Sorghum 30 % ,Corn flour 22 % ,Skimmed milk12.5 % ,Xanthan gum 1%, Yeast .5% , Salt .25% and Sugar .25%.The functional properties of gluten free bread were determined and the waterabsorption capacity of the samples ( control (A) 0.0μg TGase /g of protien, (B)5.0μg TGase /g of protien, (C) 10μg TGase /g of protien ,(D) 15μg TGase /g ofprotien and (E) wheat flour were 81, 79, 80, 81 and 78 % respectively, Theemulsification capacity results were 40.9, 40.9 ,41.9 , 42.9 and 42.9 %respectively . Foaming capacity results were 6, 9.6 , 7.5 , 5.35 and 5 , Foamingstability results were 1, 1.9 ,0.95 , 0.54, and 5.0 % respectively. Bulk densityresults were 0.84, 0.83, 0.82, 0.81 and 0.82 % respectively. Swelling capacityresults were 6, 7, 8, 10 and 8 % respectively. TGase has an impact on the waterholdingcapacity. It is presumed that the protein network formed by TGase has theability to trap water and, hence, cause an increase in the water-holding capacity.The protein fractions were determined and the albumin content of thesamples A,B,C,D and E were 2.70, 2,20, 2.10, 2.80 and 1.80 % respectively,VProlamin were 1.30, 1.0 , 1.9, 1.30 and 1.90 % respectively. Globulin were 2.70,1.70, 2.90, 3.00 and 4.60 % respectively. Glutelin were 1.70, 2.60, 2.80, 2.30 and2.40 % respectively.The protein solubility were determined and the solubility of the samples A,B, C, D, and E at pH 4 were 4.00 , 3.1 , 4.9, 3.5 and 2.2 % respectively, while, atpH 6 were 3.00 , 6.30, 5.30, 3.10 and 2.20 % respectively.Addition of TGase in different percentages to gluten free flour significantelychanged the values of farinograph . The water absorption of the samples A,B,C andD were 39.2, 39.2, 38.0 and 39.4 % respectively. The dough stability values of thesamples A,B,C and D blend were 1.1, 0.1 , 0.9 and 0.0min respectively. The doughdevelopment time of the samples A, B, C and D were 10.2, 8.6 9.9, and 9.5minrespectively.There is positive correlation between addition of TGase and waterabsorbtion when compared with wheat flour.Sensory evaluation of loaf bread showed that loaf bread made from glutenfree flour with 15μg/g of protein gained the highest score of general acceptibilityamong the GF bread 3.05