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Prebióticos e probióticos dietéticos, desempenho e higidez de juvenis de pacu Piaractus mesopotamicus (Holmberg, 1887) / Dietary prebiotics and probiotics, performance and health of pacu juvenile (Piaractus mesopotamicus (Holmberg, 1887)Cerozi, Brunno da Silva 22 June 2012 (has links)
O aumento populacional e a elevação no consumo de alimentos tem aumentado a necessidade de intensificação da aquicultura objetivando maiores produtividades para atendimento à elevação na demanda. Consequentemente, aumentam as chances de ocorrência de surtos epizoóticos dentro dos sistemas de produção, devido ao maior estresse imposto aos animais densidade elevada, manejo constante, transporte, baixa qualidade da água, etc. Alterações no estado fisiológico dos animais fazem com que seu sistema imunológico não consiga combater agentes inócuos em situações normais, mas que se tornam patogênicos nos casos de imunodepressão, levando a grandes perdas econômicas, seja com mão de obra, mortandade, medicamentos, etc. Assim, este estudo avaliou o efeito da administração individual ou conjunta de -glucano e Bacillus subtilis na dieta de juvenis de pacu, Piaractus mesopotamicus. Em um primeiro ensaio, quantidades crescentes de -glucano (60; 120; 180; 240 e 300 mg kg-1 de ração) e de B. subtilis (109 UFC g-1 de B. subtilis; 0,025%, 0,050%, 0,075%, 0,100%, 0,125%) foram adicionados a uma dieta basal extrudada (32% de proteína bruta PB; 3200 kcal kg-1 de energia digestível ED) e administrados a juvenis de pacu (8,91 ± 0,30 g) até a saciedade aparente por 75 dias, em um delineamento inteiramente aleatorizado. Ao final do período experimental, os animais foram anestesiados, pesados, submetidos à coleta de sangue e tecidos, para determinação do ganho de peso, conversão alimentar, taxa de crescimento específico, proteínas totais, albumina e globulina séricas, índice albumina:globulina (A:G), atividade da lisozima sérica, explosão respiratória de leucócitos e morfometria intestinais. Em um segundo ensaio conduzido nas mesmas condições ambientais, juvenis de pacu (2,0 ± 0,1 g; 15 peixes/aquário) foram alimentados por 59 dias com rações suplementadas pelos aditivos em questão, mais um grupo controle: -glucano de levedura 240 mg kg-1 de ração; B. subtilis comercial (109 UFC B. subtilis g-1) 0,100% de inclusão; tratamento simbiótico 240 mg de -glucano kg-1 + 0,100% de B. subtilis. Ao final do período experimental os peixes foram amostrados para determinação dos mesmos parâmetros anteriormente descritos. A inclusão dos níveis de -glucano e de Bacillus subtilis na dieta não influenciou o desempenho (P>0,05) de juvenis de pacu, mas peixes alimentados com a dieta contendo o B. subtilis consumiram mais ração (P<0,05). Não houve alterações nos parâmetros de morfologia intestinal (P>0,05), nem nos valores de explosão respiratória, atividade de lisozima, proteínas totais séricas e globulinas séricas. Quando os dois imunoestimulantes foram adicionados às dietas em combinação, também não foi observado efeito sobre os parâmetros de desempenho, explosão respiratória e atividade de lisozima, mas as proteinas totais séricas e as globulinas séricas foram positivamente influenciadas pelos tratamentos (P<0,05). As alturas de microvilosidades da porção cranial do intestino dos pacus alimentados com o tratamento simbiótico (-glucano + B. subtilis) foram maiores se comparadas ao grupo controle (P<0,05). Apesar de algumas respostas terem indicado efeito positivo sobre alguns parâmetros imunológicos e morfologia intestinal de pacus alimentados por uma combinação de -glucano + B. subtilis, não houve clara evidência que a administração simbiótica é superior à administração individual de cada imunoestimulante. / Stimulation of immune response by dietary supplements has already been proven effective in aquaculture. This work evaluates effects of dietary supplementation with the prebiotic -glucan, the probiotic Bacillus subtilis and their synbiotic combination on growth performance, immune responses, and intestinal morphology of pacu Piaractus mesopotamicus. In a first trial, a basal diet (32% crude protein; 3200 kcal kg-1) was supplemented with either -glucan (60; 120; 180; 240 e 300 mg kg-1) and B. subtilis (109 UFC g-1 of B. subtilis; 0.025%, 0.050%, 0.075%, 0.100%, 0.125%) levels and fed to groups of juvenile pacu (eight fish; 8.91 ± 0.3 g) stocked in 33 glass aquariums (70 L) for 75 days, setting up a totally randomized design trial (n=3). Fish were then weighed and had their blood drawn for determination of leucocytes respiratory burst activity, serum lysozyme activity and serum immunoglobulin concentration; intestinal tissue was sampled from two fish from each unit for micromorphology analysis. The inclusion of -glucan and Bacillus subtilis in the diet did not affect growth (P>0.05) of pacu juvenile, but fish fed diet containing levels of B. subtilis showed higher feed consumption (P<0.05). Intestinal morphology, respiratory burst activity, lysozyme activity, total serum proteins and total globulins were not affected in either inclusion of -glucan and Bacillus subtilis (P>0.05). In a second trial, a basal diet (34% crude protein; 3400 kcal kg-1) was supplemented with either -glucan (240 mg kg-1), B. subtilis (0.1 %) and -glucan + B. subtilis mix and fed to groups of juvenile pacu (15 fish; 2.0 ± 0.1 g) stocked in 16 glass aquariums (70 L) for 59 days, setting up a totally randomized design trial (n=4). Fish fed diets supplemented with -glucan + B. subtilis mix presented better growth rate, but it was not significantly different from other feeding groups. Serum total proteins and serum globulins (serum total proteins serum albumin) were affected by dietary supplements (P < 0.05); fish receiving the synbiotic treatment had higher serum globulin contents, but respiratory burst and lysozyme activity were not significantly affected. Dietary synbiotic mix altered the micromorphology of anterior intestine (P < 0.05), but the same effect was not observed in the mid and posterior intestines (P > 0.05). Dietary -glucan + B. subtilis synbiotic mix affected the intestinal ultrastructure of pacu, improved responses of immune system but did not significantly affect growth rate.
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Levedura na alimentação de poedeiras comerciais e seu impacto sobre o desempenho produtivo e qualidade dos ovos / Effect of yeast in laying hens feed it is impact on production performance and egg qualityNatália Thaís Gonçalves Koiyama 26 July 2016 (has links)
O objetivo deste trabalho foi avaliar os efeitos da inclusão de leveduras, na forma de parede celular e hidrolisada, na dieta de poedeiras sobre o desempenho produtivo, qualidade dos ovos e viabilidade econômica da suplementação destes aditivos. Dois experimentos foram realizados, para cada um deles foram alojadas 256 poedeiras distribuídas em delineamento inteiramente casualizado em 8 repetições com 8 aves. Foram avaliados os níveis de 0, 225, 450 e 900 g/t de parede celular de levedura na dieta das aves durante o período de 21 a 67 semanas de idade. Os resultados demonstraram um aumento no consumo de ração, produção e massa de ovos, além de uma maior altura do albúmen e unidade Haugh. A espessura da casca e a cor da gema também foram influenciadas pelos tratamentos. A análise da viabilidade econômica demonstrou que mesmo despendendo mais com a alimentação houve um aumento da margem bruta média, devido ao aumento da produção de ovos. Portanto, o uso da parede celular de levedura apresentou efeitos benéficos sobre o desempenho produtivo das poedeiras, como uma melhora na qualidade interna e externa dos ovos, aliado a uma maior rentabilidade da atividade. Para a levedura hidrolisada foram avaliados os níveis de 0, 1, 2 e 4 kg/t. Dois períodos foram analisados, 21 a 40 e 48 a 67 semanas de idade. A adição de levedura hidrolisada na dieta de poedeiras não apresentou melhoria das características analisadas no primeiro período, porém os benefícios surgiram a partir do segundo período. O uso da levedura além de gerar uma menor quantidade de ovos não comerciais, promoveu o aumento do consumo de ração, produção, massa e peso dos ovos, melhoria na qualidade dos ovos em relação a unidade Haugh, altura do albúmen, espessura e resistência da casca; e ainda melhorou a conversão alimentar por massa e dúzia de ovos. A suplementação de levedura hidrolisada para poedeiras proporcionou incremento da margem bruta total média em todos os níveis testados, demonstrando-se viável economicamente. A inclusão de levedura hidrolisada na dieta de poedeiras de 48 a 67 semanas de idade exerceu efeito maximizador do desempenho produtivo e qualidade de ovos, sendo economicamente viável seu uso. / The purpose of this study was to evaluate the effects of including yeast in the form of cell wall and hydrolyzed, in the diet of laying hens on production performance, egg quality and economic viability of these feed additives. Two experiments were conducted, for each of them 256 laying hens were housed and distributed in a completely randomized design with 8 repetitions of 8 birds. The level of 0, 225, 450 and 900 g/t of yeast cell wall were evaluated in the diet of birds from 21 to 67 weeks of age. The results showed an increase in feed intake, egg production and mass as well as a higher albumen height and Haugh unit. The shell thickness and yolk color were also affected by treatments. The economic viability analysis demonstrated that even spending more on feed an increase in the average gross margin due to increased egg production was observed. Therefore, the cell wall yeast showed a beneficial effect on production performance of laying hens, represented by an improvement of internal and external egg quality, combined with higher profitability. Hydrolyzed yeast was evaluated at the levels of 0, 1, 2 and 4 kg/t. Two periods were analyzed, 21-40 and 48-67 weeks of age. The addition of hydrolyzed yeast in the diet of laying hens did not show improvement of the analyzed characteristics in the first period, however the benefits occurred in the second period. The use of yeast although generate a minor amount of non-commercial eggs, promoted an increase in feed consumption, production, egg mass and weight, improving quality of eggs in relation to Haugh unit, albumen height, shell thickness and resistance; and also improves the feed conversion by eggs mass and dozen. The supplementation of hydrolyzed yeast for laying hens provided increase overall average gross margin on all tested levels, demonstrating to be economically viable. The inclusion of hydrolyzed yeast in the diet of laying hens from 48-67 weeks of age maximized production performance and egg quality, being its use economically viable.
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Avaliação do efeito de derivados de parede celular de levedura de cana-de-açúcar (Saccharomyces cerevisiae) sobre a resposta imune de cães adultosZaine, Leandro [UNESP] 23 February 2010 (has links) (PDF)
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zaine_l_me_jabo.pdf: 606188 bytes, checksum: da0b30ee696bae955544945c1be515d9 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Biorigin Sa / Vários derivados da parede celular da levedura Saccharomyces cerevisiae conhecidamente agem sobre a imunidade, no entanto a ação, especialmente da fração beta-glucano, foi pouco demonstrada em cães. Para o estudo dos possíveis efeitos sobre a imunidade na espécie canina foram empregadas quatro dietas isonutrientes, contendo uma fonte de parede celular de levedura (PCL), duas fontes de beta-glucano (BG1 e BG2) e uma dieta controle (CT). Foram utilizados 24 cães da raça beagle, adultos, divididos em quatro grupos de seis animais. As dietas foram fornecidas por um período total de 126 dias e as avaliações incluíram hemograma e avaliações bioquímicas, dosagem de anticorpos anti-Leptospira, imunofenotipagem de linfócitos sanguíneos, avaliação da concentração de IgA em fezes, teste de hipersensibilidade cutânea tardia e dosagens de citocinas em sobrenadante de cultura celular. Os animais foram submetidos a desafio antigênico com vacina contra leptospirose no dia 42. Os dados foram avaliados pelo procedimento GLM do SAS, sendo as médias comparadas pelo teste de Tukey (p≤0,1). Nos exames bioquímicos houve discreta variação entre os tratamentos e ao longo dos dias. No hemograma notou-se aumento dos linfócitos para BG2. A dosagem de anticorpos anti-Leptospira, mostrou baixos títulos, não havendo boa resposta à vacinação. A imunofenotipagem revelou um aumento dos linfócitos T totais, T helper, T citotóxicos e linfócitos B no grupo BG2 e de linfócitos T citotóxicos e linfócitos B para o grupo PCL. Apesar da variação da concentração de IgA fecal ao longo dos dias, os tratamentos não influenciaram tais parâmetros. O teste de hipersensibilidade cutânea tardia mostrou um aumento na resposta à inoculação da vacina, para os grupos PCL e BG2. Na dosagem de citocinas em sobrenadante de cultura celular, apenas foi observada diferença na quantificação de TNF-α,... / Some products from the cell wall of the yeast Saccharomyces cerevisiae are known to act on the immunity, however this action, especially of the beta-glucan fraction, has never been demonstrated in dogs. To study these effects on the immunity of dogs four isonutrient diets were made, containing one source of yeast cell wall (YCW), two sources of beta-glucan (BG1 and BG2) and a control diet (CT). 24 adult beagle dogs were used, divided in four groups of six animals. Diets were given for a 126 days period. Evaluations included complete blood count and biochemistry profile, quantification of antibodies against Leptospira, immunophenotyping of blood lymphocytes, IgA concentration in feces, delayed-type hypersensitivity test and quantification of cytokines in cell culture supernatant. Animals were exposed to antigen challenge, by the vaccine against leptospirosis on day 42. Data were analyzed by the GLM procedure of the SAS software and the means were compared by the Tukey test (p<0,01). Biochemistry profile showed slight differences among the groups. A increase in lymphocyte count was observed for BG2 treatment. Quantification of antibodies against Leptospira showed low titles, with poor response to vaccination. Immunophenotyping revealed an increase during the time in total T cells, helper and cytotoxic T cells, and B lymphocytes for BG2 and of cytotoxic T cells and B lymphocytes for YCW group. Despite the variation in fecal IgA concentration during the time, treatments did not influence these parameters. Delayed-type hypersensitivity test showed an increased response to the vaccine inoculation, for YCW and BG2 groups. In the quantification of cytokines in cell culture supernatant the only difference observed was in TNF-α concentration, being BG2 higher than CT. We concluded that both yeast cell wall and beta-glucan fraction act on dogs` immunity
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Prebióticos e probióticos dietéticos, desempenho e higidez de juvenis de pacu Piaractus mesopotamicus (Holmberg, 1887) / Dietary prebiotics and probiotics, performance and health of pacu juvenile (Piaractus mesopotamicus (Holmberg, 1887)Brunno da Silva Cerozi 22 June 2012 (has links)
O aumento populacional e a elevação no consumo de alimentos tem aumentado a necessidade de intensificação da aquicultura objetivando maiores produtividades para atendimento à elevação na demanda. Consequentemente, aumentam as chances de ocorrência de surtos epizoóticos dentro dos sistemas de produção, devido ao maior estresse imposto aos animais densidade elevada, manejo constante, transporte, baixa qualidade da água, etc. Alterações no estado fisiológico dos animais fazem com que seu sistema imunológico não consiga combater agentes inócuos em situações normais, mas que se tornam patogênicos nos casos de imunodepressão, levando a grandes perdas econômicas, seja com mão de obra, mortandade, medicamentos, etc. Assim, este estudo avaliou o efeito da administração individual ou conjunta de -glucano e Bacillus subtilis na dieta de juvenis de pacu, Piaractus mesopotamicus. Em um primeiro ensaio, quantidades crescentes de -glucano (60; 120; 180; 240 e 300 mg kg-1 de ração) e de B. subtilis (109 UFC g-1 de B. subtilis; 0,025%, 0,050%, 0,075%, 0,100%, 0,125%) foram adicionados a uma dieta basal extrudada (32% de proteína bruta PB; 3200 kcal kg-1 de energia digestível ED) e administrados a juvenis de pacu (8,91 ± 0,30 g) até a saciedade aparente por 75 dias, em um delineamento inteiramente aleatorizado. Ao final do período experimental, os animais foram anestesiados, pesados, submetidos à coleta de sangue e tecidos, para determinação do ganho de peso, conversão alimentar, taxa de crescimento específico, proteínas totais, albumina e globulina séricas, índice albumina:globulina (A:G), atividade da lisozima sérica, explosão respiratória de leucócitos e morfometria intestinais. Em um segundo ensaio conduzido nas mesmas condições ambientais, juvenis de pacu (2,0 ± 0,1 g; 15 peixes/aquário) foram alimentados por 59 dias com rações suplementadas pelos aditivos em questão, mais um grupo controle: -glucano de levedura 240 mg kg-1 de ração; B. subtilis comercial (109 UFC B. subtilis g-1) 0,100% de inclusão; tratamento simbiótico 240 mg de -glucano kg-1 + 0,100% de B. subtilis. Ao final do período experimental os peixes foram amostrados para determinação dos mesmos parâmetros anteriormente descritos. A inclusão dos níveis de -glucano e de Bacillus subtilis na dieta não influenciou o desempenho (P>0,05) de juvenis de pacu, mas peixes alimentados com a dieta contendo o B. subtilis consumiram mais ração (P<0,05). Não houve alterações nos parâmetros de morfologia intestinal (P>0,05), nem nos valores de explosão respiratória, atividade de lisozima, proteínas totais séricas e globulinas séricas. Quando os dois imunoestimulantes foram adicionados às dietas em combinação, também não foi observado efeito sobre os parâmetros de desempenho, explosão respiratória e atividade de lisozima, mas as proteinas totais séricas e as globulinas séricas foram positivamente influenciadas pelos tratamentos (P<0,05). As alturas de microvilosidades da porção cranial do intestino dos pacus alimentados com o tratamento simbiótico (-glucano + B. subtilis) foram maiores se comparadas ao grupo controle (P<0,05). Apesar de algumas respostas terem indicado efeito positivo sobre alguns parâmetros imunológicos e morfologia intestinal de pacus alimentados por uma combinação de -glucano + B. subtilis, não houve clara evidência que a administração simbiótica é superior à administração individual de cada imunoestimulante. / Stimulation of immune response by dietary supplements has already been proven effective in aquaculture. This work evaluates effects of dietary supplementation with the prebiotic -glucan, the probiotic Bacillus subtilis and their synbiotic combination on growth performance, immune responses, and intestinal morphology of pacu Piaractus mesopotamicus. In a first trial, a basal diet (32% crude protein; 3200 kcal kg-1) was supplemented with either -glucan (60; 120; 180; 240 e 300 mg kg-1) and B. subtilis (109 UFC g-1 of B. subtilis; 0.025%, 0.050%, 0.075%, 0.100%, 0.125%) levels and fed to groups of juvenile pacu (eight fish; 8.91 ± 0.3 g) stocked in 33 glass aquariums (70 L) for 75 days, setting up a totally randomized design trial (n=3). Fish were then weighed and had their blood drawn for determination of leucocytes respiratory burst activity, serum lysozyme activity and serum immunoglobulin concentration; intestinal tissue was sampled from two fish from each unit for micromorphology analysis. The inclusion of -glucan and Bacillus subtilis in the diet did not affect growth (P>0.05) of pacu juvenile, but fish fed diet containing levels of B. subtilis showed higher feed consumption (P<0.05). Intestinal morphology, respiratory burst activity, lysozyme activity, total serum proteins and total globulins were not affected in either inclusion of -glucan and Bacillus subtilis (P>0.05). In a second trial, a basal diet (34% crude protein; 3400 kcal kg-1) was supplemented with either -glucan (240 mg kg-1), B. subtilis (0.1 %) and -glucan + B. subtilis mix and fed to groups of juvenile pacu (15 fish; 2.0 ± 0.1 g) stocked in 16 glass aquariums (70 L) for 59 days, setting up a totally randomized design trial (n=4). Fish fed diets supplemented with -glucan + B. subtilis mix presented better growth rate, but it was not significantly different from other feeding groups. Serum total proteins and serum globulins (serum total proteins serum albumin) were affected by dietary supplements (P < 0.05); fish receiving the synbiotic treatment had higher serum globulin contents, but respiratory burst and lysozyme activity were not significantly affected. Dietary synbiotic mix altered the micromorphology of anterior intestine (P < 0.05), but the same effect was not observed in the mid and posterior intestines (P > 0.05). Dietary -glucan + B. subtilis synbiotic mix affected the intestinal ultrastructure of pacu, improved responses of immune system but did not significantly affect growth rate.
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Influência da fonte de carbono na produção de fruto-oligossacarídeos, na composição da parede celular e na expressão de genes relacionados à sua biossíntese em Fusarium solani (Mart) Sacc. e Neocosmospora vasinfecta E. F. Sm / Effect of carbon source on the production of fructooligosaccharides, in the cell wall composition and expression of genes related to the biosynthesis Fusarium solani (Mart) Sacc. and Neocosmospora vasinfecta E. F. Sm.Galvão, Daiane Felberg Antunes, 1978- 26 August 2018 (has links)
Orientadores: Marcia Regina Braga, Marcia Maria Camargo de Morais / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T04:21:10Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014 / Resumo: Fruto-oligossacarídeos (FOS) são frutanos de baixo peso molecular produzidos por microorganismos. O interesse em FOS vem aumentando uma vez que eles são considerados ingredientes funcionais benéficos à saúde humana. Com o objetivo de analisar como a produção de FOS e a composição da parede celular de fungos filamentosos é afetada pela fonte de carbono, os fungos Fusarium solani (URM 3338) e Neocosmospora vasinfecta (URM 3329) foram cultivados em meios contendo cinco fontes de carbono diferentes (sacarose, inulina, glucose, frutose ou glucose mais frutose, todos a 1%) e coletas foram realizadas aos 5, 10 e 15 dias de crescimento. A partir do meio de cultivo filtrado foram analisados o pH, teores de açúcar total, açúcares redutores e proteínas, a presença de FOS e atividades enzimáticas invertásica e inulinásica. A partir do micélio, a biomassa foi quantificada e a parede celular foi isolada e sua composição em açúcares neutros, ácidos urônicos e quitina analisada. Foi avaliada também a expressão relativa de genes de síntese de parede celular b-1,3-glucano sintase e quitina sintases. Os dois fungos utilizaram todas as fontes de carbono crescendo nas diferentes condições. Atividade de hidrólise foi detectada no meio contendo sacarose ou inulina para o fungo F. solani, gerando glucose, frutose e fruto-oligossacarideos como produtos havendo utilização dos monossacarídeos. O micélio deste fungo apresentou alterações visíveis no crescimento em meio sólido apenas no meio com frutose, mas foi observada igual quantidade de quitina da parede celular deste fungo quando crescido por cinco dias em sacarose e inulina, mas em menor quantidade com relação aos demais meios. As análises de expressão relativa de genes mostraram indução do gene da b-1,3-glucano sintase e repressão do gene quitina sintase 5 em sacarose e inulina com relação a condição frutose. Estes dados sugerem que a alteração na composição da parede celular do F. solani pode ter relação com a secreção de enzimas nos meios sacarose e inulina. Para N. vasinfecta, quando crescido em sacarose foi observada atividade de transfrutosilação, com a liberação de glucose e síntese de 1-cestose (FOS) no meio. Transfrutosilação também foi observada no meio que teve inulina como fonte de carbono. O micélio deste fungo apresentou alterações visíveis em meio sólido nas condições frutose e inulina, sendo mais hialino do que nas demais condições. A quantidade de quitina na parede celular deste fungo crescido por cinco dias foi maior nas condições frutose e inulina com relação às demais. As análises de expressão relativa de genes mostraram indução dos genes de quitina sintase 4 e 5 nestas duas condições em relação à sacarose. A partir dos resultados, pode-se concluir que as fontes de carbono oferecidas foram utilizadas pelos fungos, que as mesmas afetaram a composição de açúcares da parede celular e a expressão de genes de síntese de componentes da parede e que estes fungos são promissores para a produção de FOS, pois possuem enzimas que hidrolisam a inulina, além de enzimas que sintetizam oligossacarídeos a partir de sacarose por transfrutosilação / Abstract: Fructooligosaccharides (FOS) are low molecular weight fructans produced by microbes and plants. Interest in FOS has been increasing since they are considered as functional food ingredients with benefical effects in human nutrition. With the aim of examining how the production of FOS and the composition of the cell wall of filamentous fungi are affected by the carbon source, Fusarium solani (URM 3338) and Neocosmospora vasinfecta (URM 3329) were cultured in media containing five different carbon sources (sucrose, inulin, glucose, fructose or glucose plus fructose) and samples were taken at 5, 10 and 15 days of growth. From the filtered culture medium, pH, total carbohydrates, reducing sugars and proteins, the presence of FOS and inulinase and invertase activities were analyzed. Mycelium biomass was measured and the cell wall was isolated and its composition in neutral sugars, uronic acids and chitin analyzed. The expression of b-1,3-glucan synthase and chitin synthase genes was also evaluated. Both fungi utilized all the carbon sources for growing. In sucrose- and inulin-containing media, hydrolytic activity was detected in F. solani generating glucose, fructose and FOS as products. When grown on solid culture media, visible changes were observed in mycelium of this fungus only in fructose, but the amount of chitin in the cell wall was higher in the sucrose and inulin-containing media when compared to other carbon sources. The expression b-1,3-glucan synthase gene was induced and chitin synthase 5 gene repressed on sucrose and inulin media. N. vasinfecta showed transfructosilation activity when was grown in sucrose, with release of glucose and synthesis of 1-kestose (FOS) in the culture medium. Transfructosilation was also observed in the inulin-containing medium. The mycelium showed visible changes when the fungus was cultured in solid medium with fructose or inulin as carbon sources. The amount of chitin in the cell wall of this fungus when grown for five days in inulin or fructose was higher in comparison to other carbon sources. The analysis of gene expression showed induction of chitin synthase 4 and 5 genes in these two conditions in relation to sucrose. From the results it can be concluded that the carbon sources affected growth, enzymic activity, composition of the cell wall and gene expression in F. solani and N. vasinfecta, and that these fungi are promising organisms for FOS production since they secrete enzymes that hydrolyze inulin or synthesize oligosaccharides from sucrose by transfructosylation / Doutorado / Biologia Celular / Doutora em Biologia Celular e Estrutural
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Stability of microbial transglutaminase and its reactions with individual caseins under atmospheric and high pressure / Stabilität der mikrobiellen Transglutaminase und ihre Reaktionen mit Caseinen unter atmosphärischem Druck und unter HochdruckMenéndez Aguirre, Orquídea de María Pastora 03 November 2006 (has links) (PDF)
Kinetic inactivation of factor XIIIa and MTG were performed in a pressure range from 0.1 to 400 MPa at 40°C within a time from 0 to 60 min in a TRIS-acetate buffer at pH 6.0. The inactivation of both enzymes at these conditions followed a first order reaction model. The high inactivation rate constant of 26.6 x10-3/min-1 for factor XIIIa at low pressure (50 MP) indicated that this enzyme is much easier to inactivate than MTG, which achieved an inactivation rate constant value of 9.7 x10-3/min at higher pressure (200 MPa). An inactivation volume of –10.17±0.5 cm3/mol confirmed that MTG is very stable under high pressure. The stability of MTG under high pressure and thermal treatment was related to its conformational changes. Enzyme inactivation was accompanied by secondary and tertiary structure changes until an irreversible protein precipitation is achieved. The tertiary structure, represented by circular dichroism spectra in the aromatic region showed differences among native and MTG samples treated under high pressure, as well as at elevated temperature. Tyrosine bands, indicating protein unfolding, increased proportionally with increasing pressure treatment above 400 MPa. Nevertheless, compared to pressure, a maximal enhancement could be observed after thermal treatment at 0.1 MPa at 80°C. That demonstrated the exposure of hydrophobic groups to the protein surface with a concomitant protein unfolding. The spectra in the far ultraviolet region showed that increasing high pressure and high temperature lead to alterations in the secondary structure. The mathematical algorithms CONTIN used to calculate secondary structures stated that the 24.5% of alpha-helix of native MTG decreased to 17.2% after a treatment at 400 MPa at 40°C for 60 min and to 6.5% after a treatment at 0.1 MPa at 80°C for 2 min. However, beta-strand structures remained relatively stable after these several treatments. MTG is arranged in a way that the active site is located between beta-strand domains that are surrounded by alpha-helices, the results of this investigation suggested that MTG activity is related with the relative stability of alpha-helix and the outstanding stability of the central beta-strand structure. The irreversible precipitated protein observed at 600 MPa at 40°C for 60 min and 0.1 MPa at 80°C for 2 min was caused principally by the formation of disulfides bonds, because high pressure and high thermal treatment lead to the exposition of the Cys64 residue towards the solvent with the subsequent ability to react with neighbouring cysteine residues. Furthermore, the reaction between protein and reducing sugars resulted in the formation of Maillard products. Furosine, as an indicator of the early stages of Maillard reaction was measured. Concentration values of 261.0 mg/g protein from samples treated at 600 MPa and 40°C and 238.5 mg/g protein from samples treated at and 0.1 MPa and 80°C for 2 min were obtained. Pentosidine a subsequent product observed in the advanced Maillard reaction was also present. Concentrations of 13.7 and 6.7 mg/g protein were obtained in the samples treated at 600 MPa and 40°C for 60 min and 0.1 MPa and 80°C for 2 min, respectively. Kinetic inactivation studies of MTG in a pressure range from 0.1 to 600 MPa at 10, 30, 40, and 50°C within a long time range from 0 to 140 h were performed in order to study MTG stability under the simultaneous effect of pressure and temperature. The inactivation kinetic showed a first and very fast step and a second very slow step suggesting irreversible inactivation behaviour. Activation energy and entropy difference decreased with increasing pressure. Thereby, the inactivation rate constants of enzyme were less temperature dependent at high pressure. The effect of pressure and temperature on MTG inactivation had a synergistic behaviour. At temperatures of 10, 30, and 40°C, increasing pressure leads to increasing inactivation rate constants. However at 50°C a tendency change occurred. Negative activation volumes of –16.2±0.5, -13.6±0.1, -11.2±0.3 cm3/mol were obtained for 10, 30 and 40°C respectively and for treatment at 50°C a positive value of about +3.0±2.0 cm3/mol in a pressure range from 0.1 to 300 and a negative volume of –11.0±0.4 cm3/mol MPa from 300 to 600 MPa were calculated. A pressure/temperature diagram from inactivation rate constants was performed to represent MTG stability. The diagram shows that in a pressure and temperature range from 0.1 to 550 MPa and 10 to 40°C, pressure induces MTG stabilization against heat denaturation. At 50°C in range from 0.1 to 300 MPa, pressure induces also enzyme stabilization again heat denaturation, but at the same temperature and above 300 MPa the enzyme was inactivated. After MTG stability analysis, reaction kinetics from MTG with individual caseins in a TRIS-acetate buffer pH 6.0 were performed under atmospheric pressure (0.1 MPa) and high pressure (400 MPa) at 40°C. The reaction was monitored by gel permeation chromatography under in three assumptions: 1) The initial velocity kinetics was obtained from a non-progressive enzymatic reactions with the products. 2) The substrate concentration exceeded enzyme concentration. 3) The sum of the individual catalytic constants of the reactive glutamine residues inside caseins are represented by a single MTG-monomeric casein complex. Enzyme reaction kinetics of MTG with the individual caseins carried out at 0.1 MPa at 40°C showed Michaelis-Menten-Henri behaviour with maximal velocities of 2.7 x 10-3, 0.8 x 10-3, and 1.3 x 10-3 mmol/L∙min and Km values of 59 x 10-3, 64 x 10-3 and 50 x 10-3 mmol/L of beta-, alpha-s1-, and whole-casein, respectively. This suggested that MTG achieved a maximal velocity with ß-casein, but had the best affinity with acid casein followed by beta- casein and finally alpha-s1-casein. Enzyme reaction kinetics of beta-casein carried out at 400 MPa and 40°C also showed a Michaelis-Menten-Henri behaviour with a similar maximal velocity of 2.6 x 10-3 mmol/L×min, but the Km value of 144 x 10-3 mmol/L showing kinetical similarity to a non-competitive inhibition. The reaction of MTG with alpha-s1-casein under high pressure did not fit in to Henri-Michaelis-Menten kinetics. Kinetic parameters showed that the affinity of MTG to beta- and alpha-s1-casein under atmospheric pressure is higher than the affinity of MTG to these caseins under high pressure. This loss of affinity can be explained by a constant number of reactive glutamine residues of casein, although the protein is unfolding at high pressure, a decrease of enzyme activity of MTG to 74% after treatment at 400 MPa at 40°C for 15 min and self association of casein under thermal and high pressure treatment. Fur technological application, the formation of acid milk gels was studied under the influence of MTG within its range of pH stability. Simultaneous addition of MTG and different concentrations of glucono-delta-lactone (Gdl) to casein solutions (5% w/v) at 40°C was analysed. Gels firmness was accessed by oscillation rheometry and gel permeation chromatography. Oscillation rheometry data showed that the time of gelation decreased with an increasing Gdl concentration added to the system, however higher concentrations of Gdl caused the formation of weaker gels. Addition of 1 g Gdl/g protein without MTG caused gelation within 5 min and a storage module value G´ of 48.9 Pa. With the simultaneous addition of 1 g Gdl/g protein and 6 U MTG/ g protein the gelation time was 4 min and the reached storage modulus was 63.7 Pa. However, the addition of 0.21 g Gdl/g protein and 6 U/g protein MTG increase the gelation time to about 69 min, but, a higher module value G´ of 111.0 Pa was achieved. Addition of high Gdl concentration caused a rapid drop of pH below 5 leading to a fast enzyme inactivation. However addition of very low Gdl concentrations was also not optimal. The simultaneous influence of MTG and Gdl concentration on the gelation time and elastic properties was evaluated by a central composite rotatable design (CCRD). The resulting quadratic storage modulus model showed that, MTG concentration had a significant influence on storage modulus G´ and, that the firmness of the gels increase in direct proportion with MTG activity with the existence of a optimum Gdl concentration, whereas the resulting linear model of the gelation time stated that Gdl concentration has a significant influence on the gelation time, while it is independent of the MTG activity. A maximal firmness of 136 ± 2 Pa was reached between a range of 0.24 - 0.27 g Gdl/g protein and 5.8 U MTG/g within a time from 49 to 59 min. Gel permeation chromatography analysis demonstrated that acid gels induced by Gdl were formed by reversible cross-linking like electrostatic interactions and hydrogen bonds as well as disulfide bonds caused by temperature treatment. Whereas, the addition of MTG proved the formation of non-reversible cross-linking like oligomers based on Ne-(g-glutamyl)- lysine, which gave more firmness and stabilization on the casein gel network.
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Stability of microbial transglutaminase and its reactions with individual caseins under atmospheric and high pressureMenéndez Aguirre, Orquídea de María Pastora 14 September 2006 (has links)
Kinetic inactivation of factor XIIIa and MTG were performed in a pressure range from 0.1 to 400 MPa at 40°C within a time from 0 to 60 min in a TRIS-acetate buffer at pH 6.0. The inactivation of both enzymes at these conditions followed a first order reaction model. The high inactivation rate constant of 26.6 x10-3/min-1 for factor XIIIa at low pressure (50 MP) indicated that this enzyme is much easier to inactivate than MTG, which achieved an inactivation rate constant value of 9.7 x10-3/min at higher pressure (200 MPa). An inactivation volume of –10.17±0.5 cm3/mol confirmed that MTG is very stable under high pressure. The stability of MTG under high pressure and thermal treatment was related to its conformational changes. Enzyme inactivation was accompanied by secondary and tertiary structure changes until an irreversible protein precipitation is achieved. The tertiary structure, represented by circular dichroism spectra in the aromatic region showed differences among native and MTG samples treated under high pressure, as well as at elevated temperature. Tyrosine bands, indicating protein unfolding, increased proportionally with increasing pressure treatment above 400 MPa. Nevertheless, compared to pressure, a maximal enhancement could be observed after thermal treatment at 0.1 MPa at 80°C. That demonstrated the exposure of hydrophobic groups to the protein surface with a concomitant protein unfolding. The spectra in the far ultraviolet region showed that increasing high pressure and high temperature lead to alterations in the secondary structure. The mathematical algorithms CONTIN used to calculate secondary structures stated that the 24.5% of alpha-helix of native MTG decreased to 17.2% after a treatment at 400 MPa at 40°C for 60 min and to 6.5% after a treatment at 0.1 MPa at 80°C for 2 min. However, beta-strand structures remained relatively stable after these several treatments. MTG is arranged in a way that the active site is located between beta-strand domains that are surrounded by alpha-helices, the results of this investigation suggested that MTG activity is related with the relative stability of alpha-helix and the outstanding stability of the central beta-strand structure. The irreversible precipitated protein observed at 600 MPa at 40°C for 60 min and 0.1 MPa at 80°C for 2 min was caused principally by the formation of disulfides bonds, because high pressure and high thermal treatment lead to the exposition of the Cys64 residue towards the solvent with the subsequent ability to react with neighbouring cysteine residues. Furthermore, the reaction between protein and reducing sugars resulted in the formation of Maillard products. Furosine, as an indicator of the early stages of Maillard reaction was measured. Concentration values of 261.0 mg/g protein from samples treated at 600 MPa and 40°C and 238.5 mg/g protein from samples treated at and 0.1 MPa and 80°C for 2 min were obtained. Pentosidine a subsequent product observed in the advanced Maillard reaction was also present. Concentrations of 13.7 and 6.7 mg/g protein were obtained in the samples treated at 600 MPa and 40°C for 60 min and 0.1 MPa and 80°C for 2 min, respectively. Kinetic inactivation studies of MTG in a pressure range from 0.1 to 600 MPa at 10, 30, 40, and 50°C within a long time range from 0 to 140 h were performed in order to study MTG stability under the simultaneous effect of pressure and temperature. The inactivation kinetic showed a first and very fast step and a second very slow step suggesting irreversible inactivation behaviour. Activation energy and entropy difference decreased with increasing pressure. Thereby, the inactivation rate constants of enzyme were less temperature dependent at high pressure. The effect of pressure and temperature on MTG inactivation had a synergistic behaviour. At temperatures of 10, 30, and 40°C, increasing pressure leads to increasing inactivation rate constants. However at 50°C a tendency change occurred. Negative activation volumes of –16.2±0.5, -13.6±0.1, -11.2±0.3 cm3/mol were obtained for 10, 30 and 40°C respectively and for treatment at 50°C a positive value of about +3.0±2.0 cm3/mol in a pressure range from 0.1 to 300 and a negative volume of –11.0±0.4 cm3/mol MPa from 300 to 600 MPa were calculated. A pressure/temperature diagram from inactivation rate constants was performed to represent MTG stability. The diagram shows that in a pressure and temperature range from 0.1 to 550 MPa and 10 to 40°C, pressure induces MTG stabilization against heat denaturation. At 50°C in range from 0.1 to 300 MPa, pressure induces also enzyme stabilization again heat denaturation, but at the same temperature and above 300 MPa the enzyme was inactivated. After MTG stability analysis, reaction kinetics from MTG with individual caseins in a TRIS-acetate buffer pH 6.0 were performed under atmospheric pressure (0.1 MPa) and high pressure (400 MPa) at 40°C. The reaction was monitored by gel permeation chromatography under in three assumptions: 1) The initial velocity kinetics was obtained from a non-progressive enzymatic reactions with the products. 2) The substrate concentration exceeded enzyme concentration. 3) The sum of the individual catalytic constants of the reactive glutamine residues inside caseins are represented by a single MTG-monomeric casein complex. Enzyme reaction kinetics of MTG with the individual caseins carried out at 0.1 MPa at 40°C showed Michaelis-Menten-Henri behaviour with maximal velocities of 2.7 x 10-3, 0.8 x 10-3, and 1.3 x 10-3 mmol/L∙min and Km values of 59 x 10-3, 64 x 10-3 and 50 x 10-3 mmol/L of beta-, alpha-s1-, and whole-casein, respectively. This suggested that MTG achieved a maximal velocity with ß-casein, but had the best affinity with acid casein followed by beta- casein and finally alpha-s1-casein. Enzyme reaction kinetics of beta-casein carried out at 400 MPa and 40°C also showed a Michaelis-Menten-Henri behaviour with a similar maximal velocity of 2.6 x 10-3 mmol/L×min, but the Km value of 144 x 10-3 mmol/L showing kinetical similarity to a non-competitive inhibition. The reaction of MTG with alpha-s1-casein under high pressure did not fit in to Henri-Michaelis-Menten kinetics. Kinetic parameters showed that the affinity of MTG to beta- and alpha-s1-casein under atmospheric pressure is higher than the affinity of MTG to these caseins under high pressure. This loss of affinity can be explained by a constant number of reactive glutamine residues of casein, although the protein is unfolding at high pressure, a decrease of enzyme activity of MTG to 74% after treatment at 400 MPa at 40°C for 15 min and self association of casein under thermal and high pressure treatment. Fur technological application, the formation of acid milk gels was studied under the influence of MTG within its range of pH stability. Simultaneous addition of MTG and different concentrations of glucono-delta-lactone (Gdl) to casein solutions (5% w/v) at 40°C was analysed. Gels firmness was accessed by oscillation rheometry and gel permeation chromatography. Oscillation rheometry data showed that the time of gelation decreased with an increasing Gdl concentration added to the system, however higher concentrations of Gdl caused the formation of weaker gels. Addition of 1 g Gdl/g protein without MTG caused gelation within 5 min and a storage module value G´ of 48.9 Pa. With the simultaneous addition of 1 g Gdl/g protein and 6 U MTG/ g protein the gelation time was 4 min and the reached storage modulus was 63.7 Pa. However, the addition of 0.21 g Gdl/g protein and 6 U/g protein MTG increase the gelation time to about 69 min, but, a higher module value G´ of 111.0 Pa was achieved. Addition of high Gdl concentration caused a rapid drop of pH below 5 leading to a fast enzyme inactivation. However addition of very low Gdl concentrations was also not optimal. The simultaneous influence of MTG and Gdl concentration on the gelation time and elastic properties was evaluated by a central composite rotatable design (CCRD). The resulting quadratic storage modulus model showed that, MTG concentration had a significant influence on storage modulus G´ and, that the firmness of the gels increase in direct proportion with MTG activity with the existence of a optimum Gdl concentration, whereas the resulting linear model of the gelation time stated that Gdl concentration has a significant influence on the gelation time, while it is independent of the MTG activity. A maximal firmness of 136 ± 2 Pa was reached between a range of 0.24 - 0.27 g Gdl/g protein and 5.8 U MTG/g within a time from 49 to 59 min. Gel permeation chromatography analysis demonstrated that acid gels induced by Gdl were formed by reversible cross-linking like electrostatic interactions and hydrogen bonds as well as disulfide bonds caused by temperature treatment. Whereas, the addition of MTG proved the formation of non-reversible cross-linking like oligomers based on Ne-(g-glutamyl)- lysine, which gave more firmness and stabilization on the casein gel network.
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Fungal Biomass Valorization for Obtaining Functional Food-Related Materials / Valorización de biomasa fúngica para la obtención de materiales funcionales de interés en alimentaciónPérez Bassart, Zaida 22 September 2024 (has links)
Tesis por compendio / [ES] El objetivo de esta tesis doctoral ha sido proporcionar conocimientos fundamentales y prácticos relacionados con la valorización de la biomasa de setas, para comprender la relación estructura-funcionalidad de extractos acuosos ricos en ß-glucanos, en términos de capacidad inmunorreguladora, antioxidante y antiviral, así como las propiedades tecnológicas (gelificantes y emulsionantes). El objetivo de esta tesis doctoral también ha sido explorar la viabilidad de dicha biomasa en el desarrollo de materiales compostables para el envasado de alimentos.
Inicialmente, se aplicó un proceso de extracción secuencial, que implicaba varios tratamientos consecutivos tanto acuosos con y sin temperatura como alcalinos, aplicados a setas de gran consumo (P. ostreatus, L. edodes y G. frondosa), con la finalidad de comprender cómo las diferencias iniciales en la composición y la arquitectura de la pared celular afectaban a la extracción de ß-glucano. A partir de los resultados obtenidos, se analizó en profundidad la aplicación potencial de extractos acuosos, ricos en ß-glucanos, del género Pleurotus, explorando cómo la composición de los extractos y la complejidad estructural de ß-glucanos afectaban a su capacidad inmunorreguladora. Los resultados evidenciaron que tanto Pleurotus ostreatus como sus estipes mostraron los mejores resultados, con una actividad inmunoestimulante mucho mayor que las otras especies de Pleurotus exploradas.
En la segunda parte de esta tesis, se evaluaron las propiedades funcionales (antivirales y antioxidantes) y tecnológicas (gelificantes y emulsionantes) de los extractos acuosos de ß-glucano, purificados y sin purificar, de Pleurotus ostreatus y sus estipes. El proceso de purificación, como era de esperar, incrementó el porcentaje en carbohidratos (con un mayor aumento en los estipes), lo que se tradujo en una mayor viscosidad y capacidad gelificante. Además, el extracto obtenido de los estipes mostró una fuerte actividad antiviral frente a norovirus murino, probablemente atribuida a la mayor complejidad estructural de sus ß-glucanos. Aunque la presencia de proteínas en los extractos acuosos de ß-glucanos potenció sus propiedades emulsionantes, esta propiedad fue dependiente de la accesibilidad de la proteína para adsorberse en la interfase O/W, lo que también afectó a la viscosidad de las emulsiones resultantes.
La quitina y los ß-glucanos son dos de los principales carbohidratos de las setas, y tienen un gran potencial en la formación de materiales de envasado. En la última parte de esta tesis, se investigó la viabilidad de la biomasa de residuos de setas para desarrollar materiales de envasado de alimentos biodegradables y compostables. Los resultados mostraron que la composición de la biomasa de champiñón y las temperaturas de procesado tuvieron un impacto en las propiedades fisicoquímicas de los films desarrollados y, todas fueron biodesintegrables en condiciones de compostaje según la norma ISO 20200.
Por lo tanto, esta tesis doctoral representa un importante avance en la valorización de la biomasa de setas (seta entera y estipes) y pone de relieve su idoneidad para desarrollar nuevos ingredientes funcionales y materiales de envasado para aplicaciones alimentarias y de envasado de alimentos. / [CA] L'objectiu d'aquesta tesi ha sigut proporcionar els coneixements fonamentals i pràctics relacionats amb la valorització de la biomassa de bolets, per a comprendre la relació estructura-funcionalitat d'extractes aquosos rics en ß-glucans, en termes de capacitat immunoreguladora, antioxidant i antiviral, així com de les propietats tecnològiques (gelificants i emulsionants). L'objectiu d'aquesta tesi ha estat també l'exploració de la viabilitat d'aquesta biomassa pel desenvolupament de materials compostables per a l'envasat d'aliments.
Inicialment, es va aplicar un procés d'extracció seqüencial, que implicava diversos tractaments consecutius, tant aquosos amb temperatura i sense, com alcalins, aplicats a bolets de gran consum (P. ostreatus, L. edodes i G. frondosa), per tal de comprendre com les diferències inicials en la composició i l'arquitectura de la paret cel·lular afectaven l'extracció de ß-glucà. A partir dels resultats obtinguts, es va analitzar en profunditat la potencial aplicació d'extractes aquosos, rics en ß-glucans, del gènere Pleurotus, explorant així com la composició dels extractes i la complexitat structural dels ß-glucans afectaven a la seua capacitat immunoreguladora. Els resultats van evidenciar que tant Pleurotus ostreatus com les seues estipes mostraren els millors resultats, amb una activitat immunoestimulant molt més gran que la obtinguda per a les altres espècies de Pleurotus explorades.
A la segona part d'aquesta tesi, es van avaluar les propietats funcionals (antivirals i antioxidants) i tecnològiques (gelificants i emulsionants) dels extractes aquosos de ß-glucà, purificats i sense purificar, de Pleurotus ostreatus i les seues estipes. El procés de purificació, com calia esperar, va incrementar el percentatge en carbohidrats (amb un major augment en els estipes), cosa que es va traduir en una major viscositat i capacitat gelificant. A més, l'extracte obtingut dels estipes va mostrar una forta activitat antiviral contra norovirus murí, probablement atribuïda a la complexitat estructural més gran dels seus ß-glucans. Tot i que la presència de proteïnes en els extractes aquosos de ß-glucans va potenciar les seues propietats emulsionants, aquesta propietat va ser dependent de l'accessibilitat de la proteïna per adsorbir-se a la interfase O/W, cosa que també va afectar la viscositat de les emulsions resultants.
La quitina i els ß-glucans són dos dels principals carbohidrats dels bolets, i tenen un gran potencial en la formació de materials d'envasament. Així, a la darrera part d'aquesta tesi, es va investigar la viabilitat de la biomassa de residus de bolets per desenvolupar materials biodegradables i compostables d'envasat d'aliments. Els resultats van mostrar que la composició de la biomassa de bolets i les temperatures de processament van tenir un impacte en les propietats fisicoquímiques de les pel·lícules desenvolupades i, totes elles van ser biodesintegrables en condicions de compostatge segons la norma ISO 20200.
Per tant, aquesta tesi doctoral representa un important pas endavant en la valorització de la biomassa de bolets (sencers i estipes) i posa en relleu la seua idoneïtat per desenvolupar nous ingredients funcionals i materials d'envasament per a aplicacions alimentàries i d'envasat d'aliments. / [EN] This doctoral thesis was aimed at providing fundamental and practical knowledge related to the valorisation of underexploited mushroom biomass, in order to understand the structure-function relationship of ß-glucan aqueous extracts in terms of immunoregulatory, antioxidant and antiviral capacity as well as technological (gelling and emulsifying) properties. It was also the aim of this PhD thesis to explore the feasibility of mushroom biomass to develop compostable food packaging materials.
Initially, a sequential fractionation process, involving several consecutive cold or hot aqueous and alkaline treatments, was applied to widely consumed mushrooms (P. ostreatus, L. edodes and G. frondosa), in order to understand how the initial differences in composition and cell wall architecture affected ß-glucan extraction. Based on the results, the potential application of ¿-glucan aqueous extracts from Pleurotus genus was deeply analysed, thus exploring how the composition of the extracts and structural complexity of ¿-glucans affected their immunoregulatory capacity. The results evidenced that both Pleurotus ostreatus and its stipes showed the best results, with a much higher immunostimulant activity than the other explored Pleurotus species.
In the second part of the thesis, functional (antiviral and antioxidant) and technological (gelling and emulsifying) properties of purified and unpurified¿¿-glucan aqueous extracts from Pleurotus ostreatus and its stipes were evaluated. The purification process, as expected, increased the carbohydrates content (greater in those obtained from the stipes), which resulted in a greater viscosity and gelling capacity. Furthermore, the extract obtained from the stipes showed a strong antiviral activity against murine norovirus, probably ascribed to the higher structural complexity of ß-glucans. Although the presence of proteins in the ¿-glucan aqueous extracts enhanced their emulsifying properties, it depended on the accessibility of the protein to adsorb at the O/W interphase, which also affected the viscosity of the resulting emulsions.
Chitin and ß-glucans are two of the major carbohydrates of mushrooms, having a great potential in the formation of packaging materials. Thus, in the last part of this thesis, the feasibility of mushroom waste biomass to develop biodegradable and compostable food packaging materials was investigated. The results showed that the composition of mushroom biomass and the processing temperatures had an impact on the physicochemical properties of the developed films and, all of them were biodisintegrated under composting conditions according to ISO 20200.
Therefore, this PhD thesis represents a significant step forward in the understanding of the discarded mushroom biomass (whole biomass and stipes) for valorisation purposes and highlights its suitability to develop new cost-efficient functional ingredients and packaging materials for food and food packaging applications. / This work was performed with the financial support of the CIEN project BIOPRO
from “Centro para el Desarrollo Tecnológico Industrial” (CDTI), Ministry of
Science and Innovation, Government of Spain. The Accreditation as Center of Excellence Severo
Ochoa CEX2021-001189-S funded by MCIN/AEI/10.13039/501100011033 is also
fully acknowledged. his study forms part of the AGROALNEXT programme and was supported by
MCIN with funding from European Union NextGenerationEU (PRTR-C17. I1)
and by Generalitat Valenciana. Synchrotron experiments were performed at NCD
beamline at ALBA Synchrotron with the collaboration of ALBA staff (proposal
2,022,025,569). IF was supported by a postdoctoral contract grant for the
requalification of the Spanish university system from the Ministry of Universities
of the Government of Spain, financed by the European Union (NextGeneration
EU) (MS21-006). / Pérez Bassart, Z. (2024). Fungal Biomass Valorization for Obtaining Functional Food-Related Materials [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/203841 / Compendio
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