Scientists from the University of Calabria in Italy report that adding pentosans to wheat flour could enable the production of dough with tailored properties, as well as overcoming the problem of flour variability.
“Dough rheological behaviour is the result of complex interactions between different components (mainly starch, gluten and water) and the addition of pentosans introduces a new variable to be considered when dealing with dough mechanical properties,” wrote the authors in Food Research International.
There has been an increased demand for manufacturers to offer special flours, designed for specific application such as: home-made bread, pizza, spongy cakes, biscuits, and “self-leavening” flour.
Water soluble pentosans are a major non-starch component of flour. Pentosans are seen as a promising functional ingredient - potentially affecting the rheological and mechanical chatacteristics of flours and therefore showing potential for the use as a modifier in the production of speciality flours.
“Even though they were extensively studied, the effects of pentosan addition in dough is not yet completely understood and different opinions, mainly on rheological effects, can be found in literature,” report the researchers
The new study assessed the “the potential contribution of pentosans as rheological modifiers”, that could be useful in the preparation of specific flours, by applications by assessing their effects on the rheological properties of dough.
The study’s results suggested the effects of pentosans addition is variable - depending on the amount, type of pentosans and deformation amplitude.
It was also found that the addition of solubilised pentosans decreases the network strength at low temperatures, but increased it at higher temperatures. This effect was modified by increasing the pentosan levels, with a reduction in network seen at intermediate temperatures (between 50°C and 70°C).
Spray-dried pentosans appeared to be strongly modified by the drying process, and consequently a reduction in both network strength and extension was seen – suggesting they could be useful to reduce the strength of flours, making them more suitable to be processed.
The study suggests that pentosans could be used in the production of specialist flours, to alter the rheological properties of speciality dough.
“Results of this paper demonstrated that modification of rheological behaviour was found when changing some operating parameters (the amount of added pentosans and temperature),” added the researchers.
In order to attain the desired dough characteristics, pentosans concentration and temperature conditions should be properly selected, state the researchers.
The authors also suggest that rheological analysis of cereal based products could be beneficial as it “can support the addition of specific ingredients, such as pentosans, …[and can] tailor dough properties for any specific production”
Source: Food Research International
Published online ahead of print, doi: 10.1016/j.foodres.2010.08.008
“Effect of Pentosans addition on dough rheological properties”
Authors: M. Migliori, D. Gabriele