Effects of the addition of xanthan gum and rice flour to maize starch on quality of gluten-free biscuit

Introduction. The aim of this research was to study the interaction of xanthan gum and a mixture of rice flour and corn starch, its effects on the quality of gluten -free cookies, as well as optimization of the gluten -free cookie recipe to produce highquality products. Materials and methods. The effects of addition of rice flour to maize starch in ratio 6:4, 8:2 and 10:0 and the xanthan gum in amounts of 0, 2 and 4% were analysed. Texture parameters (breaking force), dimensions (spread factor), colour (browning index), water activity and total sensory score were determined as response variables. Results and discussion. An increase in xanthan concentration led to an increase in hardness, browning index and water activity while reducing the spread factor of the glutenfree biscuits. Increased amounts of maize starch in the glutenfree mixture contributed in particular to a lower hardness and a lower browning index of the gluten -free biscuits, while at the same time the spreading of the biscuits increased. An increase in the addition of xanthan gum led to an increase in hardness, browning index and water activity as well as a reduction in the spread factor of gluten -free biscuits. Meanwhile, increasing the amount of maize starch in the glutenfree mixture in combination with rice flour contributed significantly to a reduction in the hardness and browning index of gluten -free biscuits, while at the same time increasing the spread of the biscuits. The curvilinear effects of the addition of xanthan gum and maize starch on the sensory score showed that the optimal amounts were between the minimum and maximum addition values in the experiment. Conclusions. The optimal conditions to obtain gluten -free biscuits of high quality with total sensory score 7.7 were as follows: ratio of rice flour to maize starch 88.9:11.1 in combination with an addition of 1.1% xanthan gum.