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Advisor(s)
Abstract(s)
Bread is one of the most important gluten-free foods,
and it is usually connected with crumbling texture,
poor colour, low volume, unsatisfactory taste and a
short shelf-life, probably due to the lack of the viscosity
network formed by gluten. Thus, some defects of gluten-
free bread are related with inefficient gas retention
and expansion during dough leavening, which results
in a reduced volume and low crumb softness of the
breads. The current challenge is for the industry to
overcome these limitations. Furthermore, the texture
is a characteristic that depends on the structure of the
food, but also on the complex oral manipulation that
aims to grind the food. In the present work the textural
properties were analysed in breads made with special
flours without gluten produced industrially, and the
reproducibility of the results between breads from
different batches was also evaluated.
Two formulations of gluten-free flour were tested,
provided by Germen (Portugal) (designated as A) and
Credin (Denmark) (designated as B), and were also
produced samples of bread with wheat flour type
65 (sample called Control), produced by CEREALIS
(Portugal) - designated as A, B and Control samples,
respectively. For analysis of the textural characteristics,
a texturometer was used and perforation and
compression tests were performed. The properties
measured by the perforation test were: crust firmness,
crumb firmness, adhesiveness, and stickiness. In the
compression test, the characteristics evaluated were:
hardness, elasticity, cohesiveness, resilience and
chewiness. To evaluate the reproducibility, the breads
were produced in four different batches, for each type
of bread (A, B and Control), to assess whether the
characteristics were maintained on the different days
of manufacture.
The results obtained for the perforation test showed
that the loaves produced with gluten-free flours are
less firm (in the crust and in the crumbs) and less
adhesives when compared to bread made with type
65 flour (with gluten). Regarding stickiness, it can be
said that there are not many apparent differences
between the breads analysed, however bread B is
more similar to Control bread. Bread A has a greater
discrepancy between the top and the bottom in
terms of stickiness, being more intense on the top
of the bread. The compression tests showed that
in the crumb the values are identical in all studied
samples, including the control sample. However, when
analysing the complete slice, it appears that samples
A and B are considerably less hard than the Control,
due to the crust contribution. The gluten-free breads
presented lower resilience than the Control sample,
with Sample B showing the highest concordance
between the crumb and the complete slice. Moreover,
the results showed both gluten-free breads had similar
elasticity and chewiness values, both for the crumb
and for the whole slices, and higher than the wheat
bread. Regarding the reproducibility of the results, it
was possible to observe that the perforation tests are
preferable to those of compression, and that on the
other hand the samples made with the flour without
gluten type B are more uniform between batches. The results obtained in this study showed that the type
of flour, its composition and the presence or absence of
gluten significantly influence the texture of the breads
produced. Breads made with gluten-free flours were
less firm on the crust and crumbs when compared to
wheat bread. On the other hand, gluten-free breads
tend to be less sticky and slimy. Moreover, the two tests
to evaluate the texture proved to be complementary, since they allow to evaluate different characteristics,
and thus obtain a more complete profile of textural
characteristics of the breads. The reproducibility of the
results was higher for perforation tests compared to
compression tests, and on the other hand the samples
manufactured with type B gluten-free flour showed to
be more constant in their texture characteristics, when
different batches of bread were compared.
Description
Keywords
Flour Gluten free Texture analysis Compression test Perforation test
Citation
Correia PMR, Guiné RPF, Fonseca M, Batista L. (2021) Analysis of Textural Properties of Gluten Free Breads. Journal of Hygienic Engineering and Design, 34, 102-108.