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Pré-tratamento de bagaço de malte cervejeiro com ácido oxálico para solubilização de hemicelulose e obtenção de xilitol e compostos orgânicos voláteis

2024-05-14T17:59:12Z

Title: Pré-tratamento de bagaço de malte cervejeiro com ácido oxálico para solubilização de hemicelulose e obtenção de xilitol e compostos orgânicos voláteis Author: Schmidt, Aline Ruth First advisor: Bender, João Paulo Abstract: The lignocellulosic biomass of various plants has been studied in recent decades as a renewable matrix for obtaining ecologically sustainable energy sources, such as second-generation ethanol (2G) and value-added products, driving the implementation of a circular economy. Brewer's spent grain (BSG) is produced in large quantities by the brewing industry, is a low-cost raw material, with availability independent of seasonality, rich in structural carbohydrates, such as glucose and xylose, which through technological processes can be industrialized and reinserted into the economy. Thus, the present work aimed to obtain ethanol, xylitol and volatile organic compounds from the fermentation of a hydrolyzate rich in pentoses from the acid pre-treatment of malt bagasse. To this end, a series of hydrolysis tests with oxalic acid were conducted, with the best result being obtained with 4.5% catalyst and 24 minutes of reaction, in an autoclave, at 125.6 °C, with solubilization of more than 99% of hemicellulose and concentration of 14.9 g/L of xylose in the liquid fraction. The hydrolyzate from the pre-treatment step was then subjected to fermentation by three strains of Saccharomyces cerevisiae, one industrial (PE-2), and two genetically modified to allow the production of ethanol from xylose and increase tolerance to fermentation-inhibiting substances (MP-P5 and JDY-01). The analyses were conducted using a rotational central composite design to evaluate the effect of fermentation temperature and pH of the hydrolyzate on carbohydrate intake, xylitol, ethanol and volatile organic compound formation by the three strains. At the end of the experiments, an inhibitory effect exerted by the accentuated amount of oxalic acid, or oxalate, its conjugate base, present in the hydrolysates (about 45 g/L) from the pre-treatment was noticed. As a result, it was not possible to verify the accumulation of xylitol in any test, and the F12 experiment (pH 3.0 and 20 °C), with the MP- P5 strain, was the only one to present ethanol production, with 1.76 g /L generated from the consumption of all the glucose and a part of the xylose present in the medium. Even so, it was possible to identify the production of some volatile organic compounds by the yeasts, with emphasis on phenethyl alcohol, superior alcohol with a rose and honey aroma that has antimicrobial and antifungal properties, and 4-Hydroxy-2-methylacetophenone, a compound phenolic acid with important antioxidant, antitumor, analgesic and antiseptic properties, which strongly appeared in the chromatograms, with a peak area of, on average, 4% and 45%, respectively, and with potential for recovery. In addition, the F26 test (pH 9.0 and 40 °C), where the JDY-01 strain was used, showed an accumulation of linoleic acid with a peak area corresponding to 44%, which would allow its recovery. BSG, therefore, proved to be suitable for use in biorefineries, and with the proper techniques, it can become a vital part of implementing a circular economy. Publisher: Universidade Federal da Fronteira Sul Type: Dissertação

Extração, avaliação e aplicação celular de compostos fenólicos presentes na casca do pinhão Araucaria angustifolia (Bertol.) O. Kuntze

2024-05-14T17:57:00Z

Title: Extração, avaliação e aplicação celular de compostos fenólicos presentes na casca do pinhão Araucaria angustifolia (Bertol.) O. Kuntze Author: Semim, Viviane First advisor: Quast, Leda Battestin Abstract: The Araucaria angustifolia (Bertol.) O. Kuntze is found mainly in the southern region of Brazil, known by many popular names such as Brazilian pine, Paraná pine, pine, araucaria. Pine nuts mature in cones, they are large seeds that have nutritional reserves. The pine nut shell, rich in bioactive compounds, is considered unexploited agro-industrial waste, representing around 20% of the total weight of the pine nut, and is normally discarded into the environment. Bioactive compounds stand out for the properties they exert as antioxidant, anti- inflammatory and supporting agents in the treatment of diseases. In this context, the objective of this work was to evaluate the phenolic composition and antioxidant activity of in natura pine nut shell extract, through maceration and ultrasound-assisted extraction techniques, and to investigate the anticancer action of the extract on cutaneous melanoma cells of the SK-Mel-28 and A-375. The coats were separated from the seeds and dried for 24 hours at 40 °C in a forced air convection oven (Cienlab). Shells were subsequently crushed and sieved (0.210 and 0.250mm). The extracts from fresh pine nut shells were evaluated for total phenolic compounds (CFT) - by the Folin-Ciocalteu method - total antioxidant activity (AAT) - by the DPPH and ABTS radical scavenging method and antitumor activity in cutaneous melanoma cells (MC). In the extraction of total phenolic compounds (CFT), the treatments did not show a significant difference. The highest CFT content was 15.51 μg.g-1 dry mass obtained by ultrasound-assisted extraction for 30 minutes. In the evaluation of antioxidant activity by DPPH and ABTS, maceration did not show a significant difference between treatments, however, using the ultrasound method for 30 minutes, ABTS showed a significant difference (p<0.05), with 1202, 44 μM TEAC.g-1, which was subsequently applied to MC cells. Anticancer activity was evaluated by the cell viability method (MTT) by exposing melanoma cells to the crude extract and by serial dilution for 24 hours. In treatments with SK-Mel-28 cells, they did not show cell inhibition activity. Treatment on A-375 cells resulted in a significant decrease in cell viability, presenting antitumor activity at the concentrations tested (p<0.001); (p<0.0001), when compared to the control, except in the 1:100 dilution, where the treated cells did not change when compared to the control. The concentrations where the dilution factor of the Araucaria angustifolia extract were 1:1000 and 1:10 were able to inhibit the growth of tumor cells by approximately 30% in 24 hours of treatment. At concentrations where the dilution factor was 1:1 and with crude extract, a higher rate of cytotoxicity was observed, showing a significant reduction in cell proliferation with a percentage below 50% in relation to the control in these treatments. The extract for A-375 cells demonstrated effective results in preventing cell migration, potentially as a supporting agent for the treatment of cutaneous melanoma. Publisher: Universidade Federal da Fronteira Sul Type: Dissertação

Estudo e caracterização de kefir de água a base de quinoa

2024-05-14T17:13:30Z

Title: Estudo e caracterização de kefir de água a base de quinoa Author: Sanches, Flavia Leticia First advisor: Bertan, Larissa Canhadas Abstract: Quinoa is a plant species from the Chenopodiaceae family, rich in proteins, lipids and fiber, which gives it an interesting nutritional value. Despite being highly nutritious and having technological advantages, it is still little explored and known by consumers. Therefore, the objective of this work was to develop and characterize a drink, especially for the public with restrictions on the consumption of lactose, milk protein and/or vegan, based on water-soluble vegetable extract of quinoa (WVEQ) fermented with water kefir grains. Initially, an WVEQ was created, in which the effect of sucrose concentration (SC) (2; 6 and 10% (w/v)), inulin concentration (IC) (2.5; 3.0 and 3. 5% (w/v)) and xanthan gum concentration (XGC) (0, 0.08 and 0.16% (w/v)) through a central composite design (CCD) 23, containing 3 central points. The eleven formulations were subjected to fermentation with 5% (w/v) water kefir at 25±1°C for 12 hours and were subsequently characterized regarding: (i) cell growth of the grains, (ii) beverage yield, (iii) pH, (iv) soluble solids, (v) production of carbon dioxide (CO2), (vi) lactic acid and (vii) production of ethanol. The highest growth rates of kefir grains were obtained at maximum IC (3.5% (w/v)) and XGC (0.16% (w/v)), regardless of SC. Furthermore, it was possible to identify that the yield and concentration of lactic acid show opposite behavior, where the greater the production of lactic acid, there is a greater need for substrate consumption and a consecutive reduction in yield. After analyzing the dependent variables via regression analysis, no significant interactions were found (p ≤ 0.05) within a 95% confidence interval (α = 5%). Therefore, for the final stage, samples F1 (SC 2, IC 2.5 and XGC 0% (w/v)) and F8 (SC 10, IC 3.5 and XGC 0.16% (w/v)), because these are the extremes of the formulations, which are characterized in terms of proximate composition, microbiological composition of the kefir culture, analysis of organic compounds, sensory analysis and enzymatic and microbiological characterization before and after simulation of in vitro gastrointestinal digestion. In the centesimal characterization, fermentation increased the amount of proteins due to the high proteolytic activity of the microorganisms present in kefir, in addition to the increase in lipid content. The identification of microorganisms showed a prevalence of yeasts Saccharomyces sp., which explained the concentrations of ethanol identified in the composition of organic compounds through the metabolization of glucose, fructose and cellobiose. In the sensory analysis, the F8 formulation showed better results when compared to the F1 formulation. In vitro gastrointestinal digestion showed a reduction in lactic acid bacteria and yeast and an increase in acetic acid bacteria in the liquid phase for both formulations. As for the solid part, there was an increase in lactic acid bacteria and yeasts and acetic acid bacteria remained high. In the enzymatic profile, there was a reduction in all enzymes analyzed for both formulations, except for amylase in F1F, which went from 14.05 U/ mL to 39.41 U/mL. Therefore, it is concluded that the use of WVEQ as a substrate for the production of fermented beverages with water kefir culture appears to be a viable alternative for serving a specific market niche, with nutritional and technological advantages. Publisher: Universidade Federal da Fronteira Sul Type: Dissertação

Avaliação do efeito antimicrobiano e antineoplásico do extrato de macela (Achyrocline satureioides) puro e diluído em ferro dextran

2024-05-14T14:32:35Z

Title: Avaliação do efeito antimicrobiano e antineoplásico do extrato de macela (Achyrocline satureioides) puro e diluído em ferro dextran Author: Pinheiro, Mariana Faccini First advisor: Yamazaki, Ricardo Key Abstract: Achyrocline satureioides (Lam.) DC is a medicinal plant native to South America, frequently used in ethnomedicine in several south american regions, despite being rich in bioactive compounds, studies on its antimicrobial and antitumor potential are still incipient. In view of the above, the present study aimed to determine the action of the aqueous extract of A. satureioides - obtained by infusion, on the strain of Pseudomonas aeruginosa (ATCC® 27853TM) and on the human melanoma cell line (SK-Mel-28 ). The extract was characterized according to its phytochemical composition (dosage of total phenolic compounds, flavonoids and high-performance chromatographic analysis) and its in vitro antioxidant activity (using three different assays: DPPH•, ABTS•+ and FRAPP method). The antimicrobial effect was determined using an antimicrobial sensitivity test (minimum inhibitory concentration, disk diffusion and Punch Hole technique) and the antitumor action was evaluated using assays for cell proliferation, cell migration, determination of cell death and apoptosis, production of reactive species of oxygen and nitric oxide, impact on levels of protein and non-protein thiols, as well as on the expression of ectonucleotidases CD39 and CD73. It was concluded that the A. satureioides extract showed antipseudomonal and anti-melanoma activity, which was potentiated in the presence of iron dextran. The unprecedented nature of such a finding is emphasized. Publisher: Universidade Federal da Fronteira Sul Type: Dissertação