SIBI! EM BREVE O RIUFPA ESTARÁ LIBERADO! AGUARDEM!

BDTD - Biblioteca Digital de Teses e Dissertações

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2289

Biblioteca Digital de Teses e Dissertações da UFPA (BDTD). Sistema Eletrônico de Teses e Dissertações (TEDE). Projeto BDTD/UFPA e Instituto Brasileiro de Informação em Ciência e Tecnologia (IBICT).

Navegar

Agora exibindo 1 - 20 de 24

Acesso aberto (Open Access)
Adição de ácido esteárico e surfactante em filmes elaborados com proteínas miofibrilares obtidas de corvina (micropogonias furnieri).
(Universidade Federal do Pará, 2017-03-03) VIEIRA, Lorena Limão; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769
The interest in biodegradable films as food packaging is a worldwide trend that has increased significantly in recent years. The myofibrillar proteins, particularly fish ones, have been gaining interest in film technology. The films made from polysaccharides or proteins have excellent mechanical and optical properties, but these films have a high water vapor permeability (WVP). The incorporation of hydrophobic substances, such as stearic acid, into the film-forming solution, is an alternative to increase the barrier properties of the film to water vapor. But to facilitate the incorporation of the lipid in the protein matrix, it is necessary to add surfactant, which are substances capable of interacting with the protein and the fatty acid. The objective of this work was to develop and characterize films of myofibrillar proteins obtained from corvina waste (Micropogonias furnieri) using glycerol as plasticizer, sodium dodecyl sulfate (SDS) as surfactant and stearic acid (SA) as lipid, to improve the technological properties of the film. The characterization of the waste and lyophilized myofibrillar proteins (MP) was performed, indicating that the raw material had a high protein content (96.03% b.s.), important for the formation of the biopolymer matrix. A complete factorial planning was done to define the region of better mechanical, physical and barrier properties of films. The optimized biofilm was prepared with 2.84% MP, 3.18% SA, and 78.41% SDS and 30% glycerol. Concentrations of SA and SDS significantly reduced the WVP, reaching 5.87E-11 g m m-² s-¹ Pa-¹, representing a reduction of 31% when compared to the control biofilm. The mechanical properties of the optimized biofilm were favored, presenting 235.60% of elongation and 6.35 MPa of tensile strength producing stronger and more flexible films. The values of transparency were high, indicating tendency to opaque and yellowish tone, however, with excellent UV barrier properties and it can be used in light sensitive foods. The optimized film also presented good thermal stability and the microstructure revealed a structural change in the filmogenic matrix, in relation to the control, with presence of grooves and protuberances on the surface, confirmed by X-ray diffraction, which indicated the influence of SDS and SA on crystallinity of the film. A 22% increase in solubility and a slight decrease in the swelling of the optimized film were observed.
Acesso aberto (Open Access)
Adsorção de cobre (II) presente em cachaça utilizando quitosana obtida por radiação micro-ondas: caracterização e estudo cinético
(Universidade Federal do Pará, 2020-02-27) SANTOS, Lucely Nogueira dos; FERREIRA, Nelson Rosa; http://lattes.cnpq.br/3482762086356570; https://orcid.org/0000-0001-6821-6199
Cachaça is a typical drink in Brazil and has been reaching more and more the national and international market. The cachaças produced in copper stills present unique characteristics, however they may be more susceptible to suffer contamination by copper (II). Adsorption by biopolymers has shown to be a very promising technique for the removal of metal ions. Chitosan is a biopolymer derived from the deacetylation of chitin and has free amino groups in its structure, which are strongly reactive to metal ions. Considering the aforementioned aspects, this work aimed to perform the deacetylation of chitosan using microwave irradiation technology and to evaluate the capacity of the chitosan obtained in adsorbing copper (II) from cachaça. Chitin was extracted from shrimp exoskeleton, chitosan was deacetylated and its adsorption capacity was evaluated through kinetic study using mathematical models. The copper (II) concentration remaining in the cachaça, in all kinetic experiments was estimated by the spectrophotometry technique in the visible region and confirmed by microwave-induced plasma optical emission spectrometry (MIP OES). Chitosan was characterized by infrared spectroscopy with attenuated reflectance (FTIR-ATR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and molecular mass The results of the characterization showed that the microwave deacetylation process it occurred efficiently, since the chitosan obtained had satisfactory properties in terms of its main characteristics observed, degree of deacetylation (above 85%), molecular weight, morphology and crystallinity. Regarding the adsorption kinetics, the best condition for copper adsorption was 6 mg of chitosan per mL of cachaça, in an equilibrium time of 60 min which resulted in a reduction rate of 84.09% of copper in the drink, according to results obtained by MIP OES. The kinetic analysis indicated the best fit of the data by the Elovich equation, suggesting that the chemisorption mechanism controls the kinetic process. Therefore, chitosan proved to be a good adsorbent for the removal of copper in cachaça and in this respect, a promising target for future technological investments.
Acesso aberto (Open Access)
Avaliação da composição química e do potencial antioxidante de acessos de Euterpe oleracea e Euterpe precatoria para posterior aplicação como corante natural na formulação de bala de goma
(Universidade Federal do Pará, 2022-04-11) LISBOA, Camile Ramos; CARVALHO, Ana Vânia; http://lattes.cnpq.br/7856575452724939; CHISTÉ, Renan Campos; http://lattes.cnpq.br/0583058299891937
The present dissertation evaluate the chemical composition and antioxidant potential of eight different genotypes of Euterpe oleracea and eight of Euterpe precatoria, from the Active Germplasm Bank of Embrapa Amazônia Oriental (Belém/PA), in order to select the best accession for each species for later application in the formulation of gummy candies. The parameters of pulp yield, total lipids, total phenolic compounds, total flavonoids, total anthocyanins and the evaluation of antioxidant capacity by the ABTS method in the eight accessions of each species were evaluated. PL01 genotype, belonging to the species of E. precatoria, showed greater prominence compared to the other genotypes studied, for total phenolic compounds (2414.11 mg gallic acid equivalent/100 g), total monomeric anthocyanins (1822.22 mg cyanidin 3-glycoside/100 g), total flavonoids (325.07 mg quercetin equivalent/100 g) and antioxidant capacity by the ABTS method (96.54 μM trolox equivalent/g), in relation to the species of E. oleracea, the L2PL5 genotype presented better prominence in relation to its same species in the parameters of total monomeric anthocyanins (736.05 mg cyanidin 3- glycoside/100 g), total flavonoids (306.55 mg quercetin equivalent/100 g) antioxidant capacity by the ABTS method (53.77 μM trolox equivalent/g). From this first study, a genotype of each specie, based on the high levels of anthocyanins, in order to evaluate the application of lyophilized açaí in the candy formulation. of gum to monitor the stability of the natural pigment compared to a gummy bear with artificial coloring. Parameters such as pH, total acidity, total soluble solids (oBrix), total monomeric anthocyanins and instrumental color of the gummies produced during 30 days of storage at room temperature were monitored. At the end of the 30 days of storage, it was observed that there was a lower rate of degradation of total monomeric anthocyanins in the gummies with lyophilized açaí from Euterpe precatoria, compared to the gummies with lyophilized açaí from Euterpe oleracea of 1.25 x 10-1 days and 1.52 x 10-1 days, by the first order model, respectively, in addition to a lower loss of total monomeric anthocyanins, in percentagem, 48.17 % and 61.73 %, respectively. Regarding color stability, the lyophilized açaí gummies from Euterpe oleracea and Euterpe precatoria showed a perception of color change in a similar period of 20 days, being an ideal alternative of time for storage and consumption. It is concluded that the applicability of lyophilized açaí in food products can be seen as a viable alternative, resulting in foods with a good source of bioactive properties such as anthocyanins, in order to produce a healthier alternative to gummy bears.
Acesso aberto (Open Access)
Avaliação e caracterização de sementes amazônicas para fins alimentícios
(Universidade Federal do Pará, 2018-06-18) PINHEIRO, Rutelene da Cruz; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170
Many products used by the society come from the Brazilian flora, such as medicines, food and its additives, fibers, natural and essential oils, cosmetics, chemicals and biofuels. Numerous classes of chemical compounds can be extracted from plant species, such as cupuassu (Theobroma grandiflorum), tucuman (Astrocaryum vulgare Mart), peach palm (Bactris gasipaes) and mammee apple (Mammea americana L.) belonging to families Malvaceae, Palmae and Clusiaceae. These fruits are well known in the Amazon region, their pulps have excellent sensorial characteristics (aroma, flavor and texture) with wide acceptance, and great potential for use in the production of varied types of food. Aiming to provide a better use of these fruits, studies about chemical and nutritional characterization were carried out from their seeds, and the viability of these seeds to obtain polysaccharides. The seeds of cupuassu, tucuman, peach palm and mammee apple showed high nutritional value due to the presence of carbohydrates, lipids, proteins, minerals, saturated and unsaturated fatty acids, essential amino acidsand phenolic compounds in different concentrations, which make of the seeds a potential byproduct to be used in food preparations, since the concentration of ant nutritional (tannins and phytates) was identified in low concentration. Regarding the extraction of polysaccharides, there was a difference in the monosaccharide composition identified in each seed, and the mammee apple seed was prominent, due to the high percentage of glucose. The seeds of tucuman and peach palm were also distinguished by the presence of mannose (M) and galactose (G) in the proportions (M / G) of 3:1 and 4:3, respectively, characterizing the possible presence of galactomannans.
Acesso aberto (Open Access)
Caracterização da gordura da amêndoa da gordura de cupuaçu (Theobroma grandiflorum S.) obtida por extração aquosa enzimática
(Universidade Federal do Pará, 2022-09-02) SILVA, Danylla Cássia Sousa; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170; https://orcid.org/0000-0002-6002-9425
Aqueous enzymatic extraction is considered an emerging green technique that is being extensively investigated. In this work, cellulase, pectinase and protease enzymes are used in the aqueous extraction process of cupuassu fat, aiming to obtain a higher extraction yield. Different incubation systems were tested, at a temperature of 60 °C and following extraction kinetics (2 to 8 hours). The samples that obtained the highest fat extraction efficiencies were analyzed: aqueous phase, in terms of phenolic compounds and antioxidant activity, and oily phase (fats) characterized in terms of physicochemical properties, fatty acid profile, oxidative stability, thermal and bioactive compounds. The aqueous phase showed higher concentrations of phenolic compounds and antioxidant activity when compared to the oil phase. The fat samples showed approximate contents of monounsaturated and saturated fatty acids with higher concentrations of oleic and stearic, showed good oxidative stability (about 14 h) and thermal stability (close to 406 oC) and the best yield result (80.86 %) was achieved with the protease enzyme within 6 hours of incubation. The results indicated that cupuassu fats obtained by enzymatic aqueous extraction have potential for use in the food, pharmaceutical and cosmetics sectors.
Acesso aberto (Open Access)
Caracterização de óleos e gorduras vegetais amazônicas: utilização de modelo para predizer viscosidade
(Universidade Federal do Pará, 2022-06-03) FREITAS, Joice Silva de; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170; https://orcid.org/0000-0002-6002-9425
The Amazon rainforest is rich in oilseed plant species, which have fruits that are attractive due to their economic potential and biological properties. Oils from oleaginous matrices have a unique composition with physicochemical and nutraceutical properties that attract attention as a source of fatty acids. The predictive model is based on the use of mathematical equations that are more comprehensive and less limited than simple linear or polynomial models, and are able to predict a certain property using one or more physicochemical parameters. Thus, this work aimed to use a predictive model to calculate the viscosity of Amazonian oils (açaí, bacaba, tucumã) and fats (cupuaçu, bacuri and tucumã). The samples were physicochemically characterized in terms of acidity index, density, oxidative stability, peroxide, melting point, iodine index, saponification index, fatty acid composition, triacylglycerol composition, solid fat content, atherogenicity index and heterogeneity. Two predictive models were used to obtain the viscosity values of oils and fats, the model using the profile of the mass fraction of polyunsaturated and monounsaturated fatty acids and the model using the iodine and saponification index.The results showed that the oils (patauá, pracaxi, bacaba, açaí, tucumã) had high levels of unsaturated fatty acids, especially oleic acid, which has good thermal stability, while the fats (cupuaçu, bacuri and tucumã) are composed of mainly by saturated fatty acids. The oxidative stability showed that at a temperature of 110 °C, pracaxi oil and cupuaçu fat presented the highest values, while bacaba oil presented a lower value, this low stability value indicates that this sample is more conducive to oxidation. Pracaxi oil showed the highest value for the ratio between hypocholesterolemic and hypercholesterolemic fatty acids (HH), indicating that it is more nutritionally adequate. The studies to predict the regularity of Amazonian oils and fats proposed in this work may contribute to simplifying the evaluation of the physicochemical properties of important regional oleaginous raw materials on which there are no studies, but with growing industrial interest in different areas, in addition of the food area.
Acesso aberto (Open Access)
Desenvolvimento e caracterização de filmes de gelatina de peixe com carboximetilcelulose, álcool polivinílico e adição de nanopartículas de prata
(Universidade Federal do Pará, 2023-08-11) FERNANDES, Gleyca de Jesus Costa; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; https://orcid.org/0000-0001-5009-8235
The general objective of this thesis was “To develop and characterize biodegradable films of fish gelatin combined with carboxymethyl cellulose and polyvinyl alcohol, added with silver nanoparticles” and is structured into three chapters. The first chapter presents a review article that serves as theoretical support for the research carried out, which is entitled “Biodegradable polymeric blends of fish gelatin, carboxymethylcellulose and polyvinyl alcohol used as active packaging: A review”. This manuscript provides an overview of the main features and shortcomings related to the application of fish gelatin in biodegradable films. It presents information that reports the production of films from the combination of biopolymers as a good strategy to overcome their limitations, highlights carboxymethylcellulose and polyvinyl alcohol as interesting polymers to form mixed films with gelatin with improved properties and considers the possibility of incorporating active compounds , particularly silver nanoparticles, to these polymeric matrices with the aim of providing antimicrobial properties to the films and extending the shelf life of packaged foods. The second chapter corresponds to the already published article entitled “Effect of polyvinyl alcohol and carboxymethyl cellulose on the technological properties of fish gelatin films”. In this study, biodegradable films were produced by mixing gelatin/carboxymethyl cellulose (FG/CMC) and gelatin/polyvinyl alcohol (FG/PVOH) in proportions 90/10, 80/20 and 70/30 with a total concentration of 3% (m/v) of solution and 10% (w/w polymers) of plasticizer, and the effect of adding these polymers on the performance of fish gelatin films was evaluated. The results showed that the mixture of gelatin with CMC and PVOH improved the mechanical strength, water vapor barrier capacity and solubility of the films. The maximum CMC concentration promoted the highest tensile strength, while the highest PVOH content produced a film with lower solubility. FG/PVOH films were more flexible and water resistant, but presented lower mechanical and thermal resistance compared to FG/CMC. The proposed mixing systems proved to be suitable for improving the properties of fish gelatin films. Chapter three presents the article “Optimization of the process for obtaining a biodegradable nanocomposite film based on fish gelatin and carboxymethylcellulose reinforced with silver nanoparticles”. The objective was to develop a biodegradable nanocomposite film from fish gelatin (FG), carboxymethylcellulose (CMC) and silver nanoparticles (NpAg). The formulation was optimized using response surface methodology to establish the best levels of FG (2–4%), CMC (0.5–1%) and NpAg(0.005–0.01%) in order to obtain a film nanocomposite (FG/CMC-NpAg) with better mechanical and barrier properties. The optimization was done based on the responses to water vapor permeability (PVA), tensile strength (RT) and elongation (E). The optimized conditions were: 3% FG, 0.54% CMC and 0.011% NpAg. The mechanical properties, PVA, solubility, optical properties and light transmission of the optimized and control films were analyzed. The optimized FG/CMC-NpAg film showed lower elongation and transparency, but on the other hand demonstrated greater tensile and water resistance, as well as improved barrier properties in relation to water vapor and ultraviolet light, when compared to the control film. Overall, the results indicated that the biodegradable nanocomposite film developed in this study may be suitable for use as packaging material.
Acesso aberto (Open Access)
Discriminação da origem geográfica e quantificação de parâmetros de qualidade em sementes sementes de cacau (Theobroma cacao) cultivadas na amazônia utilizando espectroscopia no infravermelho próximo e ferramentas quimiométricas
(Universidade Federal do Pará, 2022-06-03) FERREIRA, Fabielle Negrão; OLIVEIRA, Marcos Enê Chaves; http://lattes.cnpq.br/9052059910078575; LOPES, Alessandra Santos; http://lattes.cnpq.br/8156697119235191; https://orcid.org/0000-0002-8584-5859
This work discusses the application of the Near Infrared Vibrational Spectroscopy (NIR) technique in cocoa samples from different regions of the state of Pará (Medicilandia, Tucumă and Tomé-açu) with the aim of predicting major components and discriminating these different geographic regions. The NIR technique was associated with exploratory analysis of spectral data, testing different regression and discrimination models. This research is divided into three chapters. The first chapter reviews the concepts related to the NIR technique, and explores the most diverse articles on the application of the NIR technique in cocoa for different evaluations, such as, for analysis of major components, identification of fraud and discrimination of cocoa in different regions, from the planet. In the second chapter, prediction models were developed for nitrogen, moisture and total lipids in non-fermented samples, since certain cocoa components are not altered during fermentation, so these major components of the seeds could be quickly predicted by FT spectroscopy-NIR using PLS regression. The third article presents the application of NIR associated with exploratory analysis of spectral data by principal components, for discrimination of cocoa beans under five different treatment conditions (raw, dry fermented, dry unfermented and fermented defatted), from the three different regions mentioned geographic areas, and the best results were obtained when evaluating the fermented cocoa samples from the three regions.
Acesso aberto (Open Access)
Efeito da adição de cera de abelha sobre as propriedades de filmes biodegradáveis elaborados com gelatina da pele de peixe
(Universidade Federal do Pará, 2022-08-22) MORAES, Vinicius Sidonio Vale; TEIXEIRA, Camilo Barroso; http://lattes.cnpq.br/7059706802675228; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; https://orcid.org/0000-0001-5009-8235
Biodegradable films are defined as thin materials made from biomolecules, which act as a barrier against moisture, gases, light and mechanical injuries and, consequently, extend the shelf life of products. Biodegradable films made from biomolecules have gained visibility today, especially those made from gelatin extracted from fish skin. Despite having good optical and mechanical properties, they have high water vapor permeability (PVA). The addition of lipids such as beeswax is a good option to solve this problem. The objective of this work was the elaboration and characterization of a biodegradable film from yellow hake skin gelatin added with beeswax using sodium dodecyl sulfate (SDS) and stearic acid as a surfactant, aiming to improve the technological properties of the film. A complete factorial design was carried out to define the region with the best barrier and solubility of the films. The planning indicated the tendency of the concentrations for the best results of the characteristics of the film. Based on this, four films of film-forming solution containing 130 ml were prepared, the first being a Control film composed of 2% gelatin and 20% glycerol; second film (F1) composed of 2% gelatin, 20% glycerol, 5% beeswax, 80% SDS and 100% stearic acid; third film (F2) composed of 2% gelatin, 20% glycerol, 10% beeswax, 80% SDS and 100% stearic acid and the fourth film (F3) composed of 2% gelatin, 20% glycerol, 15% beeswax, 80% SDS and 100% stearic acid. The thickness of the films presented heterogeneous results due to the poor incorporation of the wax in the film matrix. Likewise, the addition of beeswax to the film did not have a positive influence on PVA because of the appearance of bubbles in the film-forming solution. However, all films obtained excellent solubility results, justified by the high hydrophobicity of the wax. The films obtained results that indicate opaque films with greenish yellow tones and high luminosity, with an excellent UV barrier, and can be used in foods with sensitivity to light. The microstructure analysis showed inhomogeneous films, with bi-layer-like structures, free spaces and cracks in the matrix.
Acesso aberto (Open Access)
Estudo do processo de extração aquosa enzimática do óleo da polpa de tucumã-ída várzea(Astrocaryum giganteum Barb. Rodr.)
(Universidade Federal do Pará, 2022-06-30) SANTOS, Wanessa Oliveira dos; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170
The objective of the present work was to study the process of enzymatic aqueous extraction and to characterize the oily and aqueous fractions obtained from the pulp of tucumã-í-da-várzea (Astrocaryum giganteum Barb. Rodr.). The fruits collected in different months of the year (March, April, May, June and October) were characterized in terms of physicochemical properties (total lipids, soluble solids and instrumental color) and bioactive properties (total carotenoids, total phenolic compounds and antioxidant activity). , and the month of collection was defined based on the evaluation of these properties. The aqueous enzymatic extraction assays were carried out using a full 22-factorial experimental design, with three repetitions at the central point and four axial points (totaling eleven assays). The type of pre-treatment used and the conditions applied for the aqueous enzymatic extraction tests (enzyme, solute:solvent ratio, temperature and pH) were defined from preliminary tests evaluating different conditions, and the effect of such variables was evaluated. in the yield of extracted oil. The oil obtained in the tests of the experimental design of aqueous enzymatic extraction was characterized in terms of its chemical properties (acidity index, peroxide value, oxidative stability and total carotenoids). The bioactive properties of the two fractions (oily and aqueous) obtained in the aqueous enzymatic extraction process were evaluated by determining the content of total phenolic compounds (CFT) and antioxidant activity. In addition, the characterization of tucumã-í-da-várzea oil, obtained in the test with the best conditions for extraction, was carried out in terms of fatty acid composition, nutritional quality indices, iodine and saponification indices, and melting point. . The aqueous enzymatic extraction applied to the extraction of tucumã-í-da-várzea oil made it possible to obtain yields equivalent to conventional extraction methods, with oxidative stability comparable to traditional commercial oils, in addition to high values of total carotenoids, CFT and antioxidant activity. . In addition, the aqueous extracts obtained showed excellent chemical quality, demonstrated by the high values of CFT and antioxidant activity obtained, which indicates the great potential of application of the polar phase obtained in these processes in several uses. The tucumã-í-da-várzea oil presented a fatty acid composition rich in unsaturated fatty acids, especially oleic and linoleic acid. In addition, it showed excellent nutritional quality indices (AI and TI), being considered an oil of high nutritional value and that can be used for food purposes to replace traditional oils, such as olive oil. Based on the results of this study, the aqueous enzymatic extraction methodology is potentially viable for obtaining excellent quality tucumã-í-da-várzea oil and is environmentally friendly, as it does not produce volatile organic compounds such as atmospheric pollutants, and 2 the by-product obtained (aqueous extract) through extraction has high quality functional properties and is free from toxic products.
Acesso aberto (Open Access)
Extração de compostos bioativos de folhas de croton matourensis Aubl. com CO2 Supercrítico: determinação da composição química, atividade antioxidante e atividade biológica
(Universidade Federal do Pará, 2022-05-06) BEZERRA, Fernanda Wariss Figueiredo Bezerra; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-2324-6287
The Croton matourensis species has health benefits, due to its composition, which has a high concentration of bioactive compounds such as phenolic compounds, terpenes, phenolic acids and phenylpropanoids. The most used method to obtain its extracts is hydrodistillation, however the extraction with supercritical carbon dioxide (SC-CO2) is an environmentally friendly method, with high selectivity and capable of obtaining extracts with a high concentration of larixol, an oxygenated diterpene of high economic value and with several biological activities. In this context, the present thesis aimed to use supercritical technology to obtain extracts from leaves of C. matourensis with a high concentration of larixol and to evaluate its potential anti-inflammatory, neuroprotective and antiviral activity against the COVID-19 virus. For this, in the first stage of the thesis, the extraction of C. matourensis leaves with SC-CO2 was carried out under different conditions of temperature (40 and 50 °C) and pressure (100 to 400 bar), the supercritical extraction was compared with hydrodistillation (HD) and hexane extraction (HE) through the evaluation of the mass yield, chemical composition and antioxidant activity of the extracts, then the experimental model of focal ischemia in the motor cortex of rats was carried out using the extract obtained in the best operating condition with SC-CO2. The highest yields were obtained in HE (5.73 ± 0.26%) and in the condition at 50°C/400 bar (5.60 ± 0.06%), which were statistically equal (p > 0.05), the supercritical condition was more advantageous in obtaining larixol (48.49%) compared to HE (2.93%). The extracts obtained by the different methods showed a high value of total phenolic compounds (51.81 ± 2.03 to 79.53 ± 1.19 mgGAE/g of extract), total flavonoids (2.50 ± 0.20 - 6.89 ± 0.45 mgQE/g of extract) and antioxidant activity with maximum inhibition percentage equal to 83.26 ± 0.58% at a concentration of 14 mg/mL. The focal cerebral ischemia study revealed that the animals treated with the C. matourensis extract showed a greater reduction in the lesion area than those treated with the control solution (Tween 5%), suggesting its potential anti-inflammatory and neuroprotective effect. In the second stage of the thesis, an in silico study was carried out to evaluate the interactions between the larixol ligand and four SARS-CoV-2 receptors. The molecular docking results showed that the mode of interaction played a fundamental role in the interaction with larixol, mainly in the interaction with Spike- protease. The study showed through the affinity energy that the ligand had stable conformations, forming a stable complex with the receptors, conforming to the catalytic site of the receptors. Molecular docking, molecular dynamics and Gibbs free energy data showed that larixol can bind to the binding compartment of receptors, evidencing its potential role as an antiviral agent or agent used in conjunction with other therapies that provide a line of defense against diseases associated with the coronavirus. Thus, the thesis showed that the extract of C. matourensis leaves obtained with SC-CO2 showed a high concentration of larixol, with potential anti-inflammatory, neuroprotective and antiviral activities, presenting potential to be applied as an input in the food, cosmetic and pharmaceutical industries.
Acesso aberto (Open Access)
Extrato polissacarídico de cogumelo Pleurotus ostreatus pode melhorar as propriedades tecnológicas do filme de gelatina de peixe
(Universidade Federal do Pará, 2020-02-19) FREITAS, Maurício Madson dos Santos; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769
The aim of this papert was to evaluate the influence of the polysaccharide extract (POP) obtained from the mushroom Pleurotus ostreatus on the technological properties of fish gelatin films. The optimization conditions of this study were: 3.0% gelatin (GA), 6.26% plasticizer and 1.0% polysaccharide extract (POP). Under these conditions it was possible to obtain values of 5.30x10-11 g.m.m-2, s-1.Pa-1 of WPV, 17.78% of tensile strength and 15.56% of elongation. The optimal film (POP-GA) showed antioxidant activity, adequate visual and structural characteristics, as demonstrated by FTIR, XDR and SEM analyzes. Therefore, the technological properties found in the film with polysaccharide extract and gelatin, have potential for application in the food industry, as well as in the pharmaceutical industry.
Acesso aberto (Open Access)
Farinha de mandioca (Manihot esculenta) e tucupi: uma abordagem analítica utilizando espectroscopia no unfravermelho próximo (NIRS) e ferramentas quimiométricas
(Universidade Federal do Pará, 2022-04-25) POMPEU, Darly Rodrigues; SOUZA, Jesus Nazareno Silva de; http://lattes.cnpq.br/3640438725903079; PENA, Rosinelson da Silva; http://lattes.cnpq.br/3452623210043423
The near infrared spectroscopy (NIRS) coupled to chemometrics has been used as an alternative tool for quick and reliable solutions. Cassava flour (CF) can be classified as fermented and non-fermented types. Tucupi is a yellow broth, acidic, mostly aromatic and widely used in Regional dishes in Para state. This thesis proposed to apply for the first time the NIRS associated with chemometrics to predict quality parameters from CF and tucupi, as well as to discriminate fermented and non-fermented CF. One hundred six samples of CF was investigated and nine physicochemical parameters of CF were evaluated. Calibration equations with independent validation were developed to predict all parameters using the partial least square regression method. The performance of models was evaluated by the root mean standard error of calibration (RMSEC) and validation (RMSEV), and R2 values. The aW (RMSEC = RMSEV = 0.05), moisture content (RMSEC = 0.35%; RMSEV = 0.45%) and pH (RMSEC = 0.16; RMSEV = 0.18) could be predicted (R2 > 0.727) by NIRS coupled to multivariate analysis. NIRS coupled to Principal Component Analysis–Linear Discriminant Analysis (PCA-LDA) was also used to investigate the classification of fermented and unfermented CF. The use of NIRS spectra allows to obtain better performance parameters (training accuracy: 86.3–93.8%; validation accuracy: 84.6–96.2%) to discriminate fermented and unfermented CF than the use of the physicochemical properties (training accuracy: 80%; validation accuracy: 84.6%). NIRS was also used to predict nine quality physicochemical properties of tucupi Sixty-five samples of tucupi were used in this study. The performance of models was evaluated by the R2, RMSEC, root mean standard error of cross-validation (RMSECV) and RMSEV values. The total soluble solids contents could be predicted (R2 > 0.727; RMSEC = 0.184%; RMSECV = 0.411%; RMSEV = 0.338%) by NIRS coupled to multivariate analysis. NIRS and chemometrics proved to be a powerful tool to predict quality parameters in CF and tucupi as well as to discriminate fermented and non-fermented CF.
Acesso aberto (Open Access)
Ferramentas estatísticas aplicadas nos diferentes métodos de secagem de gelatina de peixe e no desenvolvimento de bala de goma comestível
(Universidade Federal do Pará, 2021-11-22) MATIAS, Cleidiane da Silva Araújo; REGO, José de Arimateia Rodrigues do; http://lattes.cnpq.br/4163468898377462; https://orcid.org/0000-0003-0891-6438; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; https://orcid.org/0000-0001-5009-8235
Fish skin gelatin is a collagen product partially denatured by heat, with great potential for application in several areas of industry and thus the use of this biomaterial will add value to waste from the fishing industry and will contribute to reducing environmental impacts. The objectives of this study were: a) to optimize the drying methods by forced convection of hot air and combined with infrared radiation of gelatin extracted from fish skins, using fractional planning and rotational central composite design; b) verify the effect of different drying methods (freeze-drying, forced hot air convection, combined method, infrared radiation and refractance window) on the technological, functional, structural, thermal and rheological properties of gelatin, evaluated by ANOVA and principal component analysis; and c) prepare gummy candy using fish gelatin, cassava starch and powdered cupuaçu, through mixing planning. According to the results obtained, the desirability function showed that 59.14 °C for 12.35 h was the most effective condition for hot air convection drying and for the combined process, the optimized region was infrared temperature and drying time. 70 °C/2h with oven time/temperature of 3.51h at 70 °C. Regarding the evaluation of the five drying methods, the results were that the principal component analysis explained the accumulated variation of 99.87% of the data and that lyophilization was the method that provided the best preservation of gelatin properties, although drying convective and refractance window also showed good results, demonstrating that they are techniques with great potential for the production of gelatin. The desirability function defined the best conditions for the elaboration of the gum, in 25% of fish gelatin, 15% of cassava starch and 7% of cupuaçu powder. Therefore, the relevance of controlling the variables of the drying methods as a strategy for the production of biomaterials with standardized biochemical composition is of great interest, to obtain desirable physical, technological and functional properties necessary for the different applications of gelatin. In addition, the study suggests that there is great potential in the use of fish gelatin associated with the use of cassava and cupuaçu starch in the preparation of confectionery gum, providing better technological and functional properties of the final product
Acesso aberto (Open Access)
Funcionalidades de peptídeos provenientes de biomassas de oleaginosas amazônicas
(Universidade Federal do Pará, 2025-04-22) PANTOJA, Gabriela Vieira; FONTANARI, Gustavo Guadagnucci; http://lattes.cnpq.br/6654478241936919; HTTPS://ORCID.ORG/0000-0002-8417-263X; MARTINS, Luiza Helena da Silva; http://lattes.cnpq.br/1164249317889517; https://orcid.org/0000-0003-1911-4502
The use of agro-industrial by-products has been increasingly emphasized, as it focuses on sustainability and resource scarcity issues. Moreover, industrial processing by-products may also contain bioactive molecules. Bioactive peptides are molecules that exhibit a wide range of functionalities, including antimicrobial and antioxidant activities. Therefore, the aim of this study was to obtain protein hydrolysates with antioxidant and antimicrobial activity from the residual cakes of Amazonian biomasses tucumã (Astrocaryum vulgare), murumuru (Astrocaryum murumuru), and andiroba (Carapa guianensis) through enzymatic hydrolysis. To achieve this, the protein extraction was first optimized, and once the conditions of pH, ratio, and extraction time were defined, concentrated proteins were obtained and subsequently subjected to enzymatic hydrolysis using trypsin and alcalase. These hydrolysates were tested for phenolic compounds, antioxidant activity, antimicrobial activity, and separated by highperformance liquid chromatography (HPLC). The results of the study were positive regarding antioxidant activity, with tucumã hydrolysates showing the highest content. The andirobaalcalase and tucumã-trypsin hydrolysates exhibited moderate microbial inhibition activity, with this result tending, according to Pearson correlation, to be due to the peptide fractions obtained. Thus, it was possible to conclude that the use of residual oilseed cakes from the Amazon for the extraction of bioactive peptides is a viable practice for generating high-value by-products.
Acesso aberto (Open Access)
Hidrólise da quitosana: obtenção de um extrato enzimático e caracterização do produto hidrolisado
(Universidade Federal do Pará, 2022-08-09) GONÇALVES, Cleidiane Gonçalves e; FERREIRA, Nelson Rosa; http://lattes.cnpq.br/3482762086356570; https://orcid.org/0000-0001-6821-6199; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; https://orcid.org/0000-0001-5009-8235
Chitin, extensively found in crustaceans exoskeletons, insects, and microorganisms, has limited usage due to its low solubility in aqueous solution, requiring its partial deacetylation to obtain chitosan. Chitosan's depolymerization has attracted considerable attention, as its oligomers have high water solubility, biocompatibility, and non-toxicity, as well as beneficial properties such as antimicrobial, antioxidant, and antitumor properties. For this reason, in this research, a review article was produced (Chapter I) based on the main methods of chitosan hydrolysis, besides analyzing the parameters that influence the acquisition, and characteristics of hydrolysis results, effectively and at a lower cost. Among the approaches studied, enzymatic hydrolysis excels due to its control ease and performance under milder conditions, making it possible to use low-cost enzymes belonging to the glycoside hydrolases group. Thus, enzymatic hydrolysis was defined as a technique for various sizes of chitosan acquisition (Chapter II) through the production of an enzymatic extract (integral enzymatic extract - IEE) from a filamentous fungus strain. The enzyme identification present in the IEE showed exo-chitinases, endo-chitinase, and cellobiohydrolase. Considering the same reaction conditions, the IEE showed greater efficiency than the commercial enzyme (Celluclast 1.5 L®), which was used as a parameter because it is an enzyme capable of cleaving the β-1,4-glycosidic bond of chitosan - similar to chitosanase, besides presenting a lower cost. The IEE reduced the molecular weight of chitosan by 47.80; 75.24 and 93.26% at 2.0; 5.0, and 24 h, respectively. Through the FTIR analysis, a lower absorbance of the spectral signals of chitosan oligomers was detected, and the crystallinity reduced after 3.0 h of hydrolysis. Based on this study, we can infer that enzymatic hydrolysis, under established conditions, is effective at obtaining lower molecular weight chitosan using unpurified crude extract.
Acesso aberto (Open Access)
Influência do fungo cladosporium cladosporioides no índice de qualidade e perfil aromático de sementes de cacau (Theobroma cacao L.) fermentadas
(Universidade Federal do Pará, 2020-11-17) KONAGANO, Evelyn Mayumi Hanawa; FERREIRA, Nelson Rosa; http://lattes.cnpq.br/3482762086356570; LOPES, Alessandra Santos; http://lattes.cnpq.br/8156697119235191
Cocoa is a fruit that has great scientific and economic importance. However, the existing microbial diversity between lots and locations, results in different products, in relation to physical, chemical and sensory attributes. Thus, Araujo et al. (2014) proposed variables that can be used in order to standardize the quality indices of this raw material, in addition to what is already governed by legislation. In addition, there are several studies that use starter cultures of bacteria and yeasts in the fermentation of cocoa seeds, in order to obtain beans with superior quality and desirable aromas, in addition to resulting in a more homogeneous fermented raw material between different batches and locations. However, there are still no reports of the use of filamentous fungi as a starter culture, despite having biotechnological potential, mainly due to the excretion of several enzymes. A species that has already been reported in the fermentation of cocoa seeds is Cladosporium cladosporioides, which produces antifungal metabolites aimed at plant pathogens, in addition to having pectinase, laccase, glucanase, amylase, cellulase and xylanase enzymatic activity, important for the improvement of the cocoa bean fermentation process. The objective of this study is, therefore, to evaluate the influence of this filamentous fungus during the fermentation process, in an unprecedented way, through physicochemical and microbiological analyses. For this, two fermentation experiments were carried out: without inoculum (control) and with starter culture. The use of filamentous fungus did not significantly impact the formation of aromatic compounds in the almonds, compared to the control experiment. However, the presence of C. cladosporioides had a significant influence on the percentage of well-fermented almonds (p ≤ 0.05), through the cutting test, as a probable consequence of the lower content of total phenolic compounds, and of catechin and epicatechin. In addition, there was a lower concentration of acetic acid and a higher content of bioactive amines (p ≤ 0.05), when compared to the control experiment. These observed aspects were confirmed through multivariate analysis. Based on these results, it can be said that the use of C. cladosporioides proved to be promising and could provide improvements in fermented and dried cocoa beans.
Acesso aberto (Open Access)
Obtenção e avaliação dos extratos e óleos de canela e cipó d’ alho e aplicação em filmes biodegradáveis: estudo experimental e teórico
(Universidade Federal do Pará, 2022-08-30) NASCIMENTO, Fabiana Cristina de Araújo; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306; JOELE, Maria Regina Sarkis Peixoto; http://lattes.cnpq.br/2618640380469195; https://orcid.org/0000-0001-5442-0615
Various spices such as dried fruits and food grains are prone to contamination by filamentous fungi, such as the species Aspergillus Niger, increasing the risk of ingestion of mycotoxins by the population. The production of biodegradable films added to extracts and essential oils can give the same antifungal properties. Thus, this study aimed to develop biodegradable films based on cassava starch with addition of extracts and oils of cinnamon and garlic vine and evaluate its efficiency against the fungus Aspergillus Niger. The ethanol and aqueous extracts were obtained by Soxlet extraction and maceration, respectively, while the oils were obtained by hydrodistillation. To identify the major compounds of the extracts and oils, NMR and Gas Chromatography analyzes were performed. These compounds identified were selected as ligands before the enzyme glucose oxidase produced by the fungus for the theoretical study through Molecular Docking. The extracts and oils were evaluated in antifungal diffusion tests in discs and wells, respectively. The biodegradable films were prepared with extract and oils of cinnamon and garlic vine that showed better performance in antifungal tests. All the elaborated films were evaluated in the antifungal test by means of the technique of diffusion in discs. In the theoretical study through Molecular Docking, all the ligands present in the extracts and oils showed hydrogen bonds with the key amino acid residues of the enzyme glucose oxidase being Histidine (His 559 A), Threonine (Thr 110 A) and Arginine (Arg 512 A). In the antifungal tests, the ethanolic extract of the plant species garlic vine showed a higher inhibition halo of 15mm at a concentration of 20mg/ml while the antifungal tests for oils, at volumes of 1 µl; 5 µl and 10 µl revealed the formation of inhibition halos of 25mm; 28mm and 30mm for cinnamon oil. While, in the film with the oil of the vine of garlic, the inhibition of the germination of said fungus occurred during 9 days of experiment. The antifungal tests of the films revealed that the films with surfactant containing garlic vine oil did not present sporulation halos and neither mycelial growth on films 1 and 2 during the 48h of the experiment, inhibition of the growth of the fungus through the films.
Acesso aberto (Open Access)
Óleos e gorduras da Amazônia: produção de bases lipídicas especiais por interesterificação enzimática e predição das propriedades físicas
(Universidade Federal do Pará, 2023-08-30) SILVA, Dayala Albuquerque da; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170; https://orcid.org/0000-0002-6002-9425
The lipid modification methods can increase the potential application of the Amazonian oils and fats in the food industry. In addition, the determination of the physical properties, such as density and viscosity, are fundamental to promote the industrial application of blends of oils and fats. In this context, the first part of this study aimed to obtain blendsin different proportions of pracaxi oil/cupuaçu fat (PC) and pracaxi oil/palm stearin (PS) (% w/w) (40:60, 50 :50, 60:40 and 70:30) and use enzymatic interesterification to change their properties. Pure samples and blends, before (NIE) and after (IE) enzymatic interesterification, were characterized. Samples with the greatest potential for food applications (ratio of 70:30) were characterized by X-ray diffraction, optical microscopy and thermal analysis. The second part of this study aimed to measure the density and viscosity of passion fruit oil, pracaxi oil and palm stearin, as well as their respective binary blends(40:60, 50:50, 60:40 and 70:30), at different temperatures (303.15 to 363.15 K). And perform the fitting of experimental data to mathematical models available in the literature for the prediction of these properties. The results obtained in the first part of the study indicated that the blends with the highest proportion of pracaxi oil (70:30) had the lowest indices of atherogenicity (AI) (PC 0.21; PE 0.34) and thrombogenicity (IT) (PC 0.38; PE 0.55). The fats (cupuassu fat and palm stearin) showed good oxidative stability (> 3.0 h) and contributed to increase the stability and plasticity of the lipid bases obtained. Enzymatic interesterification increased the plastic range of PC blends and reduced the solid fat contente (SFC) of PS blends. Interesterification caused a reduction in the consistency of the blends, which shows the improvement in textural properties. The β crystalline form was reduced in the interesterified blends. The crystals found in the blends showed more stable polymorphic forms, while the interesterified blends showed a reduction in the β crystalline form and the presence of crystals in the α form, which is less stable. In relation to the experimental determination and data modeling of density and viscosity of blends of passion fruit oil, pracaxi oil and palm stearin, it was verified that the linear model used for the prediction of the density behavior presented excellent adjustment parameters, with R 2 values greater than 0.99 (0.9927 – 1.0) and low RMSE values (3.14x10-5 – 1.19x10-3) and χ 2 (1.77x10-9 – 2.56x10-6). For viscosity, the Andrade, modified Andrade and Arrhenius models were the ones that presented the best fits, with coefficients of determination (R2) greater than 0.99 (0.9939 – 0.9993), and low RMSE values (5.72x10-3 – 4.78x10- 2) and χ 2 (0.0001 – 0.0032). Based on the Arrhenius model, it was found that pracaxi oil had the highest activation energy (28.21 kJ/mol), contributing to the greater sensitivity to temperature variation of PS blends. The models that presented the best fit parameters can be reliably used to predict the behavior of the pure samples and blends studied, and thus can be used to model the operations involved in the processing of these vegetable oils and fats.
Acesso aberto (Open Access)
Revestimento comestível incorporado com tocoferóis e aplicação em Castanhado-Brasil (bertholletia excelsa bonpl.) para monitoramento do perfil de oxidação lipídica
(Universidade Federal do Pará, 2024-02-29) COSTA, Danusa Silva da; TAKEUCHI, Katiuchia Pereira; http://lattes.cnpq.br/1724899631394370; https://orcid.org/0000-0002-0731-8279; LOPES, Alessandra Santos; http://lattes.cnpq.br/8156697119235191; https://orcid.org/0000-0002-8584-5859
Brazil nuts are a non-timber product of great importance to extractivist families. They contain many nutrients and are rich in lipids. However, from collection to oil extraction, Brazil nuts are exposed to various degrading conditions such as humidity, light, and heat due to exposure to the environment, and these conditions can intensify the lipid oxidation of this product. For this reason, developing an active coating is an alternative for protecting and preserving Brazil nuts from lipid oxidation. The aim was to develop an active edible coating incorporated with tocopherols and apply it to Brazil nuts to monitor their lipid oxidation profile at different storage times. Films were prepared by casting. Four blends, called B, L, LT, and LT2, were prepared using fixed amounts of cassava starch + carboxymethyl cellulose + sorbitol and water (3 g + 1.5 g + 0.2 g + 100 g, respectively), soy lecithin was added in a proportion of 20% in relation to the tocopherol mix, formulation L was prepared with the same amount of lecithin as LT2. The amount of tocopherol mix was added to the mixtures in the following proportions: B - 0, L - 0, LT - 0.0005 g, and LT2 - 0.010 g. Tests were carried out on thickness, water solubility, water content, weight, contact angle, permeability, mechanical tests, antioxidant activity, biodegradability, color, thermogravimetry, and FTIR. The films were characterized as biodegradable, antioxidant, and hygroscopic and suitable for application as a coating on Brazil nuts. Viscosity, creaming index, centrifugation, pH, and color of the solutions forming the coatings were evaluated, making it possible to characterize the blends as a non-Newtonian and highly stable pseudoplastic fluid. The Brazil nuts were immersed in the coating-forming solutions, dried at 45°C for 19 hours, stored at 25°C, and evaluated at 1, 7, 15, 30, 45, 60, 90, and 120 days of storage. By official methods, tests were carried out on mass loss, browning index, conjugated dienes and trienes, oxidative status, and accelerated oxidation index. All the coatings applied minimized oxidation at some stage during storage. However, the coatings added with the tocopherol mix minimized dienes, trienes, the iodine index, the peroxide index, p-anisidine, and the total oxidation index. The accelerated oxidation test showed that the nut oil under study underwent some changes in its oxidative state, although the use of the coatings largely preserved them. The models applied to the accelerated oxidation test data made it possible to estimate the half-life of the Brazil nuts, so it was found that the LT coating showed a value of 129.86h for the half-life time in the firstorder model. The principal component analysis (PCA) applied to the physicochemical characterization data and the induction time revealed that the oil from nuts uncoated presented itself in isolation as being extremely influenced by the oxidative indices evaluated, presenting an explained variability of the data greater than 75% in most of the storage times. PCA also showed that the oil from Brazil nuts coated with LT and LT2 was negatively influenced by most of the oxidative indices, in which case this is an advantage, as it demonstrates lower rates of lipid oxidation in these samples. Developing a film with antioxidant properties and applying it as a coating on Brazil nuts made it possible to verify some levels of protection for the nuts. We suggest applying the blends developed as a film or active coating to other food products that need protection against light and oxidation.