01. Universidade Federal Rural de Pernambuco - UFRPE (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/1
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Item Caracterização e avaliação do potencial de gelificação dos polissacarídeos extraídos da Arthrospira (Spirulina) platensis(2025-03-10) Silva, Sara Cadete da; Bezerra, Raquel Pedrosa; Silva, Marllyn Marques da; http://lattes.cnpq.br/5819032802869221; http://lattes.cnpq.br/1466206759539320; http://lattes.cnpq.br/5393058542194680Arthrospira platensis, conhecida como Spirulina é uma cianobactéria filamentosa amplamente distribuída em diversos ambientes e valorizada por seu alto teor nutricional e metabólitos bioativos. Composta majoritariamente metabólitos bioativos, como proteínas, carboidratos, lipídeos e minerais, que podem ser influenciados por fatores ambientais. Os polissacarídeos se destacam por suas propriedades funcionais e bioativas, incluindo efeitos imunomoduladores, antioxidantes e antivirais. Embora pouco estudados em comparação com os de macroalgas, além de apresentarem potencial gelificante, sugerindo aplicações em encapsulação. Portanto, o objetivo deste trabalho é caracterizar bioquimicamente e avaliar o potencial gelificante dos polissacarídeos extraídos da Arthrospira platensis. O microrganismo Arthrospira platensis foi cultivada em meio de cultura Schlösser modificado, com adição de 0,2% de milhocina, em agitação e iluminação constantes. Ao final do cultivo a biomassa produzida foi concentrada e ressuspendida em etanol absoluto (1:8), aquecida a 70 °C por 4 horas para a extração dos polissacarídeos. Os polissacarídeos foram ressuspendidos em solução de Savage para remoção de proteínas e lipídios residuais e utilizados para determinação de carboidratos totais, carboidratos redutores, carboidratos não redutores, teor de sulfatação e gelificação em soluções de cátions monovalente (NaCl), bivalente (CaCl₂) e trivalente (FeCl₃) a 100 mM e pH 6. A extração de polissacarídeos de Arthrospira platensis com etanol como precipitante obteve um rendimento de 31%. Na concentração de 10 mg/mL, as dosagens de carboidratos totais, redutores, não redutores e teor de conteúdo sulfatado foram de 0,89 mg/mL, 0,28 mg/mL, 0,6 mg/mL e 1,4 mg/mL respectivamente. Testes de gelificação com cátions monovalente (NaCl), bivalente (CaCl₂) e trivalente (FeCl₃) a 100 mM e pH 6 não resultaram em formação de geis, embora a solução de polissacarídeo concentrado a 1% tenha mostrado resistência à diluição na presença de CaCl₂. A Arthrospira platensis apresentou bom rendimento na extração de polissacarídeos e alto teor de conteúdo sulfatado. Apesar de não terem formado geis com cátions, mostrou-se resistência à diluição com CaCl₂, indicando potencial funcional e necessidade de estudos adicionais para otimizar suas propriedades gelificantes.Item Desenvolvimento e aplicação de cobertura de quitosana e levana na conservação pós-colheita de manga minimamente processada(2021-12-06) Santos, Rebeca Fernandes dos; Maciel, Maria Inês Sucupira; http://lattes.cnpq.br/2091651168946523; http://lattes.cnpq.br/1088437585305186Brazil is a great fruit producer due to the climatic conditions that favor the cultivation of tropical fruits. Among the cultures that stand out for their high production and export is mango. Mango (Mangifera indica L.) is one of the tropical fruits most consumed by Brazilians, having high nutritional value, such as vitamin C, β-carotene, and minerals. Because they are perishable products, such as fruit, they reduce losses from their production until they reach the consumer, and this annual waste of tons of food causes an economic loss, in addition to environmental impacts. Chitosan is a polysaccharide that has antifungal activity and semi-permeable properties, decreasing the respiration rate and water loss of fruits. Levana is also a polysaccharide used in the food industry as a core and flavor fixative, thickener, and stabilizer in dessert gels. This study aimed to develop a coating for application in minimally processed mangoes from a combination of levan and chitosan, determining the best proportion between them that presents satisfactory characteristics and properties to store at different prices over a while. The topping was prepared at a concentration of 90% w/v chitosan and 10% w/v levan with a concentration of 0.5% v/v glacial acetic acid and 1% w/v glycerol, and then applied to the mango pieces that were stored at temperatures of 25 ± 2ºC and 2 ± 1ºC. The samples were analyzed every 3 days for color, soluble solids, water activity, moisture, titratable acidity, and pH. Mango slices stored at a temperature of c were not analyzed for showing fungus on the fourth day of storage. Mango slices at 2 ± 1°C temperature not alternated probably from water activity, pH and humidity during the entire storage time. There was a significant increase during the storage period in the soluble solids content, titratable acidity and as variables color L*, a*, and b*. There was also a delay in darkening and an increase in yellow pigmentation. The coating with chitosan (90% w/v) and levan (10% w/v) present satisfactory characteristics for application in minimally processed mangoes. Physical analyzes increased that coating could be effective in increasing shelf life, as it delayed browning, likely undistorted pH, and water activity.Item Prospecção da atividade antimicrobiana de polissacarídeos extraídos das paredes celulares das leveduras Kluyveromyces marxianus, Kluyveromyces lactis e Saccharomyces cerevisiae(2021-02-26) Araújo, Isabelle Maria Feitosa de; Ferreira, Éder Galinari; http://lattes.cnpq.br/7670722046479986; http://lattes.cnpq.br/5044579569126838Polysaccharides from the most diverse sources, may have pharmacological activities such as, for example, antioxidant, immunomodulatory, anticoagulant and antimicrobial. Bearing in mind that this last activity has not yet been evaluated, according to our bibliographic survey, for the cell wall polysaccharides of the yeasts Kluyveromyces marxianus and Kluyveromyces lactis, the objective of this study was to verify the antimicrobial activity of polysaccharides extracted from the cell walls of the yeasts Kluyveromyces marxianus CCT7735 and Kluyveromyces lactis CBS2359 and compare them to a non-Kluyveromyes yeast like Saccharomyces cerevisiae CAT-1. The susceptibility tests were performed in Petri dishes (90 x 15 mm) using the Kirby-Bauer disc-diffusion method as recommended by the M 100 supplement of the 29th edition of the Clinical & Laboratory Standards Institute. Ten microliters of the polysaccharide solution (10 mg/mL) solubilized in distilled water and sterilized by filtration were deposited on sterile paper discs (6 mm). Polysaccharides were tested against Escherichia coli ATCC 25922 (positive control: 100/10 μg of piperacillin-tazobactam); Staphylococcus aureus ATCC 29213 (positive controls: 30 μg of cefoxitin and 10 units of penicillin); Pseudomonas aeruginosa ATCC 27853 (positive controls: 100/10 μg of piperacillin-tazobactam and 10 μg of gentamicin); Klebsiella pneumoniae ATCC 700603 (positive control: 10 μg gentamicin) and Enterococcus faecalis ATCC 29212 (positive controls: 30 μg tetracycline and 10 units of penicillin). None of the cell wall polysaccharide samples evaluated inhibited the growth of the pathogenic bacteria strains tested. Thus, at least in native molecules, polysaccharides did not show antimicrobial activity. We suggest that further studies be carried out with the samples evaluated, either for other pharmacological applications/activities or with the chemical modification or modification of the concentration of these polysaccharides, followed by a new test for antimicrobial activity, among others.