Percorrer por autor "Kato-Schwartz, Camila Gabriel"
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- Estudo da estabilidade e atividade biológica de bagaço de uva (Merlot) após simulação da digestão gastrointestinal e fermentação colónicaPublication . Corrêa, Rúbia C.G.; Haminiuk, Charles Windson Isidoro; Barros, Lillian; Dias, Maria Inês; Calhelha, Ricardo C.; Kato-Schwartz, Camila Gabriel; Correa, Vanesa G.; Peralta, Rosane M.; Ferreira, Isabel C.F.R.A produção de vinho representa hoje em dia uma das maiores atividades agroindustriais a nível mundial. Como consequência gera uma enorme quantidade de subprodutos (bagaço e borras) que representam por vezes até 30% das uvas vinificadas, sendo a maioria completamente descartados sem tratamento adequado e/ou outras finalidades [1-4]. O bagaço de uva representa, por isso, um abundante e acessível subproduto industrial que contém uma grande variedade de compostos bioativos, nomeadamente fenólicos, que têm sido relacionados com benefícios para a saúde do consumidor [l]. O objetivo deste estudo foi mimetizar a digestão gastrointestinal e a fermentação colónica de bagaço de uva de Merlot, de forma a avaliar uma possível redução do conteúdo em fitoquímicos, correlacionando o perfil de compostos fenólicos com as suas atividades biológicas. Assim, foram caracterizados três extratos de bagaço (inicial, digerido e fermentado) relativamente ao seu conteúdo em compostos fenólicos antociânicos e não antociânicos por HPLC-DAD-ESI/MS. Além disso, foi também a valiado o seu potencial antioxidante, antibacteriano e citotóxico para células tumorais e não-tumorais. Os compostos fenólicos mais abundantes identificados nas três amostras estudadas foram um dímero de (epi)catequina tipo B, (+)-catequina e (-)-epicatequina. Foram identificados vinte compostos fenólicos não antociânicos na amostra inicial (66 mg/g de extrato), tendo sido significativamente reduzidos para 11 compostos após digestão invitro. Foram identificadas cinco antocianinas, no entanto, as quantidades diminuíram imenso após digestão e fermentação. Pelos resultados obtidos podemos concluir que o processo de digestão in vitro promoveu drásticas reduções qualitativas e quantitativas no perfil de compostos fenólicos no extrato micial de bagaço de uvas Merlot. Tais alterações podem estar relacionadas com a diminuição de algumas bioatividades do extrato, como é o caso das propriedades antioxidantes e antibacterianas, embora não de forma diretamente proporcional. No entanto, a fermentação colónica teve um efeito positivo sobre o potencial citoóxico do extrato em linhas celulares tumorais humanas. Há ainda um conhecimento muito escasso sobre a estabilidade dos compostos fenólicos de Bagaço de uva e propriedades bioativas durante a digestão gastrointestinal e fermentação colónica, no entanto, os resultados obtidos poderão ser de grande utilidade para o desenvolvimento de novos suplementos nutracêuticos e produtos alimentares funcionalizados.
- Laccases in food processing: Current status, bottlenecks and perspectivesPublication . Backes, Emanueli; Kato-Schwartz, Camila Gabriel; Corrêa, Rúbia C.G.; Moreira, Regina de Fátima Peralta Muniz; Peralta, Rosely Aparecida; Barros, Lillian; Ferreira, Isabel C.F.R.; Zanin, Gisella Maria; Bracht, Adelar; Peralta, Rosane M.Background: Laccases (benzenediol:oxygen oxidoreductases, EC 1.10.3.2) catalyze the oxidation of a wide variety of organic and inorganic substrates, typically p-diphenols with a concomitant reduction of oxygen (O2) to water. Several molecules naturally occurring in foods and beverages (e.g., phenols, carbohydrates, unsatured fatty acids and thiol-containing proteins) can be modified by laccases. Hence, the interaction between laccase and these molecules can and has been widely explored by the food industry for various technological purposes. Scope and approach: The present work aims at providing a critical review on the current uses of laccases in food processing, at discussing the main bottlenecks for its popularization, and at presenting future perspectives. Both scientific reports and patents, covering preferably the last five years, were considered. Key findings and conclusions: Several traditional uses of laccases in food processing including baking, beverage, and dairy industries were detailed. Special efforts were developed, however, in analyzing future perspectives. The latter includes the application of laccases in the synthesis of new compounds with functional properties, such as antioxidant and antimicrobial activities. No less attention was devoted to the recent developments in the field of crosslinking of polymers, such as proteins and polysaccharides. Scaling up of the production of the laccase itself and especially of the novel products derived from its applications in the food sector will be essential for cost reduction and, consequently, for market expansion.
- Overproduction of laccase by trametes versicolor and Pycnoporus sanguineus in farnesol-pineapple waste solid fermentationPublication . Backes, Emanueli; Kato-Schwartz, Camila Gabriel; Oliveira Junior, Verci A. de; Uber, Thaís Marques; Santos, Luís F. O. dos; Corrêa, Rúbia C.G.; Bracht, Adelar; Peralta, Rosane M.The effect of farnesol, a sesquiterpene alcohol, on the production of laccases by Trametes versicolor and Pycnoporus sanguineus in pineapple waste solid-state fermentation was evaluated. Extracellular laccase production reached a maximum of 77.88 5.62 U/g (236% above control) in farnesol-induced cultures of T. versicolor on the 17th day, whereas in a similar P. sanguineus culture, a maximal laccase activity of 130.95 2.20 U/g (159% increase) was obtained on the 17th day. A single 45KDa laccase was produced by both fungi under the influence of farnesol. These and other data allow us to conclude that farnesol acted as an inducer of the same form of laccase in both fungi. Farnesol disfavored fungal growth by increasing the lag phase, but it also clearly improved the oxidative state of the cultures. Contrary to the results obtained previously in submerged cultures, farnesol did not promote hyperbranching in the fungal mycelia. This is the first demonstration that farnesol is an excellent inducer of laccases in T. versicolor and P. sanguineus in solid-state cultivation. In quantitative terms, the results can be regarded as an excellent starting point for developing industrial or at least pre-industrial procedures to produce laccases using T. versicolor and P sanguineus under the stimulus of farnesol.
- Potential anti-diabetic properties of Merlot grape pomace extract: an in vitro, in silico and in vivo study of α-amylase and α-glucosidase inhibitionPublication . Kato-Schwartz, Camila Gabriel; Corrêa, Rúbia C.G.; Lima, Diego de Souza; Sá-Nakanishi, Anacharis B. de; Gonçalves, Geferson A.; Seixas, Flávio Augusto Vicente; Haminiuk, Charles Windson Isidoro; Barros, Lillian; Ferreira, Isabel C.F.R.; Bracht, Adelar; Peralta, Rosane M.A practical approach to control glycemia in diabetes is to use plant natural products that delay hydrolysis of complex sugars and promote the diminution of the release of glucosyl units into the blood plasma. Polyphenolics have been described as being effective in inhibiting amylases and α-glucosidases. Grape pomace is an important sub product of the wine industry, still rich in many compounds such as polyphenolics. In this context, the purpose of this study was to search for possible effects of a grape pomace extract on salivary and pancreatic α-amylases and α-glucosidase, as well as on intestinal glucose absorption. The Merlot grape pomace extract (MGPE) was prepared using a hydroalcoholic mixture (40% ethanol + 60% water). In vitro inhibition was quantified using potato starch (for amylases) and maltose (for α-glucosidase) as substrates. In vivo inhibition was evaluated by running starch and maltose tolerance tests in rats with or without administration of MGPE. Ranking of the extract compounds for its affinity to the α-amylases was accomplished by computer simulations using three different programs. Both α-amylases, pancreatic and salivary, were inhibited by the MGPE. No inhibition on α-glucosidase, however, was detected. The IC50 values were 90 ± 10 μg/mL and 143 ± 15 μg/mL for salivary and pancreatic amylases, respectively. Kinetically this inhibition showed a complex pattern, with multiple binding of the extract constituents to the enzymes. Furthermore, the in silico docking simulations indicated that several phenolic substances, e.g., peonidin-3-O-acetylglucoside, quercetin-3-O-glucuronide and isorhamnetin-3-O-glucoside, besides catechin, were the most likely polyphenols responsible for the α-amylase inhibition caused by MGPE. The hyperglycemic burst, an usual phenomenon that follows starch administration, was substantially inhibited by the MGPE. Our results suggest that the MGPE can be adequate for maintaining normal blood levels after food ingestion.
- Stability and biological activity of Merlot (Vitis vinifera) grape pomace phytochemicals after simulated in vitro gastrointestinal digestion and colonic fermentationPublication . Corrêa, Rúbia C.G.; Haminiuk, Charles Windson Isidoro; Barros, Lillian; Dias, Maria Inês; Calhelha, Ricardo C.; Kato-Schwartz, Camila Gabriel; Correa, Vanesa G.; Peralta, Rosane M.; Ferreira, Isabel C.F.R.Grape pomace is an abundant/accessible food industry by-product that contains a wide range of phenolic compounds, which have been related to several health benefits and bioactivities. The aim of this study was to mimic the gastrointestinal digestion and the colonic fermentation of Merlot grape pomace, in order to unravel possible phytochemical contents reductions and the processes associated with them, as a tentative to relate the phenolic compound profiles of the extracts with their biological properties. LC-DAD-ESI/MS suggested that the in vitro digestion process promoted drastic qualitative and quantitative reductions in the phenolic compounds profile of the Merlot grape pomace crude extract. Such alterations could be related to the decreases of some bioactivities of the extract, which seems to be the case of antioxidant and antibacterial properties, although not in a directly proportional manner. However, the simulated colonic fermentation seems to have a positive effect over the extract's antiproliferative potential.