Roberta Cruz Silveira Thys

Dr. Roberta Cruz Silveira Thys

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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2013 in Food Science and Technology
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RTRoberta Cruz Silveira Thys
Roberta Cruz Silveira Thys
AAAndréia Gomes Aires
Andréia Gomes Aires
LMLigia Damasceno Ferreira Marczak
Ligia Damasceno Ferreira Marczak
CNCaciano Pelayo Zapata Noreña
Caciano Pelayo Zapata Noreña
Technological functional properties of native and acid-thinned pinhão (seeds of Araucária angustifolia, Brazilian pine) starches were evaluated and compared to those of native and acid-thinned corn starches. The starches were hydrolyzed (3.2 mol.L-1 HCl, 44 ºC, 6 hours) and evaluated before and after the hydrolysis reaction in terms of formation, melting point and thermo-reversibility of gel starches, retrogradation (in a 30-day period and measurements every three days), paste freezing and thawing stability (after six freezing and thawing cycles), swelling power, and solubility. The results of light transmittance (%) of pastes of native and acid-thinned pinhão starches was higher (lower tendency to retrogradation) than that obtained for corn starches after similar storage period. Native pinhão starch (NPS) presented lower syneresis than native corn starch (NCS) when submitted to freeze-thaw cycles. The acid hydrolysis increased the syneresis of the two native varieties under storage at 5 ºC and after freezing and thawing cycles. The solubility of NPS was lower than that of native corn starch at 25, 50, and 70 ºC. However, for the acid-thinned pinhão starch (APS), this property was significantly higher (p < 0.05) when compared to that of acid-thinned corn starch (ACS). From the results obtained, it can be said that the acid treatment was efficient in producing a potential fat substitute from pinhão starch variety, but this ability must be further investigated

23 April 2022 in Journal of Food Processing and Preservation
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Journal Article
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MVMatheus Cardoso Vieira
Matheus Cardoso Vieira
ABAdriano Brandelli
Adriano Brandelli
RTRoberta Cruz Silveira Thys
Roberta Cruz Silveira Thys

7 March 2022 in Cereal Chemistry
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Journal Article
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CECésar D. Ebling
César D. Ebling
RTRoberta Cruz Silveira Thys
Roberta Cruz Silveira Thys
MKManuela Poletto Klein
Manuela Poletto Klein

8 December 2023 in Foods
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CBCarolina Bueno
Carolina Bueno
RTRoberta Cruz Silveira Thys
Roberta Cruz Silveira Thys
BTBruna Tischer
Bruna Tischer
Gluten-related disorders, including celiac disease, wheat allergy, and non-celiac gluten sensitivity, have emerged as a significant phenomenon affecting people worldwide, with an estimated prevalence of nearly 5% globally. The only currently available treatment for this disease involves the exclusion of gluten from the diet, which is particularly challenging in the case of bakery products. Gluten-free bread (GFB) presents certain disadvantages when compared to traditional wheat bread, including inferior sensory attributes, technological characteristics, and lower protein and fiber content. Numerous studies have focused on strategies to improve these aspects of GFB. However, there are limited reviews regarding the content of the bioactive compounds of GFB, such as polyphenols. Polyphenols are molecules found in various foods that play a vital role in protecting the body against oxidative stress. This is particularly relevant for individuals with gluten intolerance or celiac disease, as they often experience increased oxidative stress and inflammation. Therefore, the objective of this review is to explore the use of different strategies for increasing the polyphenolic content and the antioxidant properties of GFB. Gluten-free cereals and pseudocereals are the most used matrices in GFB. Buckwheat can be a valuable matrix to enhance the nutritional profile and antioxidant properties of GFB, even more so when the whole grain is used. In the same way, the addition of various by-products can effectively increase the bioactive compounds and antioxidant activity of GFB. Furthermore, regarding the contribution of the phenolics to the bitterness, astringency, color, flavor, and odor of food, it is essential to analyze the sensory properties of these breads to ensure not only enriched in bioactive compounds, but also good consumer acceptance. In vitro studies are still in few number and are very important to execute to provide a better understanding of the bioactive compounds after their consumption.

1 January 2022 in Anais da Academia Brasileira de Ciências
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Journal Article
Open access
LCLetícia F.X. Costa
Letícia F.X. Costa
CKCaroline Isabel Kothe
Caroline Isabel Kothe
TGTiela T. Grassotti
Tiela T. Grassotti
RGRaquel P. Garske
Raquel P. Garske
BSBeatriz N. Sandoval
Beatriz N. Sandoval
Ana Paula FrazzonAna Paula Frazzon
Ana Paula Frazzon
The purpose of this study was to compare the composition and stability of bacteria and fungi communities during the propagation of sourdoughs prepared with organic or conventional whole wheat (Triticum aestivum) flours from South Brazil. Sourdoughs were prepared and samples were collected during different fermentation times (0 to 216 h). Total DNA of sourdough samples were extracted and the 16S rRNA gene and Internal Transcribed Spacer region were sequenced by MiSeq-Illumina. A total of 43 and 56 OTUs were identified and defined as core taxa in the bacterial and fungal communities, respectively. The analysis revealed increases in the relative abundances of the lactic acid (Pediococcus pentosaceus, Weissella hellenica and Limosilactobacillus pontis) and acetic acid bacteria (Gluconobacter frateurii and Acetobacter tropicalis) during the sourdough propagation. The filaments fungi, Alternaria tenuissima, Fusarium culmorum, Fusarium petersiae and Microdochium seminicola remained more stable in organic than conventional during propagation cycles. After 216 h of fermentation, both sourdoughs were dominated by acid- and salt-tolerant yeast Issatchenkia orientalis (syn Pichia kudriavzevii, and Candida glycerinogenes). In conclusion, there were no significant differences in microbial communities among the sourdough samples. This study revealed that both flours contain autochthonous LAB, AAB, and yeasts with biotechnological applications in sourdough bread-making.

15 October 2019 in Journal of Culinary Science & Technology
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Journal Article
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RFRenata Ferraz
Renata Ferraz
SFSimone Hickmann Flôres
Simone Hickmann Flôres
JFJeverson Frazzon
Jeverson Frazzon
RTRoberta Cruz Silveira Thys
Roberta Cruz Silveira Thys
This study aimed to assess the influence of different cell concentrations of Lactobacillus plantarum and Saccharomyces cerevisiae in sourdough bread. Seven experimental breads resulting from a central composite design using the response surface methodology were analyzed with regards of sensory attributes, acidification characteristics, specific volume, crust color and bread hardness. The amount of L. plantarum inoculated had a direct effect on acidification characteristics and final bread crumb, indicating that the maximum cell concentration leads to bread crumb with lower pH. Results from taste and aftertaste reveled a correlation between pH and acceptability of the bread. A decrease in crumb hardness was found with higher amounts of lactobacilli and yeast, but regarding specific volume, no significant difference was observed between breads. Sourdoughs with no addition of S. cerevisiae resulted in breads with a more intense crust color. Textural improvement and sensory acceptance are achieved using different optimal concentrations.