Numerous studies have shown that mushrooms are a source of
biologically active compounds, such as polyphenols, which have
antifungal, antibacterial, antioxidant and antiviral effect. Porcini
(Boletus edulis) is one of the best quality mushroom because it is rich
in protein whose composition is similar to the composition of animal
origin protein, an excellent source of fibres, vitamins, minerals and
polysaccharide. As porcini does not contain starch and sucrose, it is
especially recommended for diabetics. Modern diet is mailny based
on the use of food based on wheat flour, and baking industry has
offered to consumers in the second half of the 20th century products
named "healthy food" obtained from wheat flour with the addition of
other kinds of flour which contain components that have a positive
effect on human health. Starting with the assumption that the addition
of porcini flour can improve the nutritional and physiological value of
wheat flour, in dissertation, the co...ntent of the ingredients essential for
nutritional and energy value of porcini flour was determined, and the
rheological properties of dough were tested. Acylglycerols, and fatty
acids content, the content of the free and bound polyphenols in the
mixture of wheat and porcini flour and their antioxidant activity were
also determined. The separate part of the dissertation consists of the
examination of the effect of mixing and thermal processing of dough
from a mixture of wheat and porcini on the antioxidant activity, as
well as on the content of some phenolic acids. A porcini mushroom
from the eco-regions Piskupovo - Leskovac was used in the
examination, and the flour was obtained by drying fresh mushrooms
and subsequent grinding and sieving. The solid-liquid extraction for
extracting the free polyphenols, and a method of alkaline hydrolysis
for isolating bound polyphenols was used. Rheological properties of
dough were determined by the methods of determining the quality of
flour by farinograph and extensograph and amylograph, while a
polyphenol content and antioxidant activity of extracts were
determined by corresponding spectrophoto-metric methods. GC-MS
method was used for determination of the fatty acids composition,
and HPLC for determinationofthe content of individual acylglycerols
and specific phenolic acids.
The product obtained from the mixture of wheat and porcini flour was
characterized by „ratio of thermal processing“, loss of mass and
volume increase after thermal processing. The results show that the
addition of porcini flour is a good way to increase both the nutritional
value and the antioxidant activity of wheat flour, as a flour mixture
have a higher content of protein, lipid, ash, cellulose, tannin, free fatty
acids, mono-acylglycerols, total unsaturated fatty acids, content of
minerals (Mg, Na, K and Fe) and the content of total polyphenols, and
the extracts of free and related polyphenols from porcini flour have
significantly higher anti-oxidant activity compared to the wheat flour.
After dough mixing and thermal processing, the content of free
polyphenols is higher than the content in a mixture of flour, and 87%
of the total content of detected phenolic acids remains retained. The
product obtained from a mixture of wheat and porcini flour by
described recipe have the higher content of total polyphenols, a better
antioxidant activity, a smaller mass loss during thermal processing
and a higher volume, compared to product made only from wheat
flour. In order to obtain food products with satisfactory rheological
properties which are simultaneously enriched by porcini ingredients,
it is recommended that the flour mixture contains 10-15% of the
porcini flour.
Faculty:
University of Niš, Faculty of Technology, Leskovac
