EFFECT OF SUGARS ON THE RHEOLOGICAL CHARACTERISTICS OF BISCUIT DOUGH AND QUALITY OF BISCUITS

Sugars, depending on the level and type, influenced the various rheolo gical characteristics of biscuit dough. Increasing the sugar content f rom 250 to 350 g kg(-1) reduced the extrusion time from 70 to 23 s, co nsistency from 866 to 616 N s, hardness from 814 to 512 N and apparent biaxial extensional viscosity from 2.54 x 10(5) to 1.41 x 10(5) Pa s. The development of gluten was also reduced, as indicated by a decreas e in the elastic recovery from 0.515 to 0.38 mm. Spread as well as thi ckness of the biscuits increased with sugar level. Density as well as compression strength were reduced significantly (from 632.6 to 513.5 k g m(-3) and from 118.4 to 89.2 kg, respectively) reflecting improvemen t in the texture. Incorporation of an additional 20 g kg(-1) reducing sugars like dextrose, invert syrup, liquid glucose and high fructose c orn syrup, which are normally added to improve the colour of biscuits further changed the rheological characteristics in a similar way. Amon g the reducing sugars, liquid glucose and invert syrup produced greate r changes in rheological characteristics particularly in adhesiveness and stickiness, while high fructose corn syrup had a greater effect on the colour of biscuits.