Dough Rheological Charact Of Broad Bean- Wheat Composite And The Semi Hard Biscuit Formular Optimization

Broad bean is rich in starch and protein, low-fat and possesses a relatively high nutritional value crop. With broad bean powder added to wheat flour in different gluten degree, TA.XT PLUS, RVA, DSC were used to study the structure characteristics of texture, tensile, pasting and thermodynamic properties of broad bean-wheat composite flours. Based on above, possible compositions design for high quality biscuit were developed. HI value of biscuits were determined by in-vitro enzymatic hydrolysis method to predict their effects on blood glucose. Main research results were as follows:(1) With the addition of broad bean powder increased,the hardness, chewiness, resilience of dough of high gluten flour composite lifted, the adhesiveness, springiness, cohesiveness of dough gradually decreased. For wheat flour with 10% broad bean powder added, compared to that of control group, the extensibility, plasticity of dough had a certain degree of enhancement. But for the effect of broad bean powder showed different rates on three types of wheat flours based on the gluten degree, significant difference were detected on hardness, resilience on that of high gluten composition dough. When the addition of broad bean powder were the same, the effects on high, medium and low gluten wheat flour were on the rise by this sequence, from which gluten contents could be summarized to be the element factor in this phenomenon.(2) As the composite of broad bean powder increased, tensile distance and extension area of in dough of broad bean-wheat composite flour reduced and R/E ratio increased. Additional of 10% broad bean powder compared with that of control wheat flour, the overall effects on high gluten composite, medium gluten and low gluten were similar, but the amplitude decreased, showing that the additional of broad bean flour had negative effect on tensile property to dough. Tensile distance, extension area, R/E ratio of dough produced from broad bean-high gluten composite flours illustrated significant differences and extension area of dough of broad bean-medium gluten composite flours also differed. Based on same level of broad bean powder, the effect of broad bean powder on extensibility of dough also differed, dilution effect caused by broad bean powder on that of high gluten flour was small while the effect on that of low gluten flour was relatively large.(3) Peak viscosity, the lowest viscosity, final viscosity and retrogradation values gradually grew with bean powder composition unceasingly increased, significant differences in peak viscosity,minimum viscosity, final viscosity and setback of high gluten composite flour and low gluten composite flour groups were detected. Tc, Tp and H of flour increased gradually as the percentage of broad bean powder blended enlarged, effects of the broad bean powder on wheat flour pasting property in high gluten, plain and low gluten types were basically the same.(4) Broad bean powder and plain flour measured as main ingredient, broad bean semi hard biscuits formula optimized is, by weight of 100 g mixed powder: cooking oil 15%, xylitol 20%, baking soda 0.8%, ammonium bicarbonate 0.4%, salt 0.5 %, KGM 0.1%, water 30%. Backed goods’ hardness was 1804.64±177.38 g, and the score was 89.8±1.48, both reached former expectations.(5) The moisture of broad bean semi hard biscuits was 1.84% and the alkalinity was 0.33%, rating between the plain semi hard biscuits and sugar free biscuits, that meets requirements in national standards. The bean semi hard biscuits’ spread ratio was 11.45±0.40 and presented even thickness. Bean semi hard biscuits showed colour value L of 76.3±0.36%, a of 2.77±0.07% and b value of 20.03±0.67%, all biscuits were uniformly colour yellow. The bean semi hard biscuits hydrolysis index was 89.51±0.00, estimated glycemic index rated 88.85±0.00, which was higher than that of sugar free biscuits sample but lower than the breakfast semi hard biscuits sample and white bread sample, the hydrolysis and blood glucose index have a obvious dissimilarity comparing to those two groups. An appropriate amount of broad bean powder can reduce the glycemic index of biscuits.