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Produção, caracterização e métodos de conservação de hidrolisado proteico provenientes de resíduos do processamento de Tilápia (Oreochromis niloticus)SILVA, Juliett de Fátima Xavier da 28 February 2014 (has links)
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Previous issue date: 2014-02-28 / CAPEs / Carcaças e vísceras constituem um importante resíduo de processamento de peixes, podendo
representar cerca de 70% do peso corporal da tilápia (Oreochromis niloticus). Esse material é
uma fonte de biomoléculas, dentre elas proteínas e proteases, com propriedades interessantes
para processos biotecnológicos como a produção de hidrolisado proteico de peixe (HPP). O
objetivo do primeiro estudo foi avaliar o uso de resíduos do processamento de tilápia para
produzir HPP. Assim, três condições de produção foram avaliadas: duas utilizando hidrolise
enzimática com enzimas extraídas do intestino da tilápia em diferentes concentrações (HPP100,
100 mg de tecido/mL e HPP600, 600 mg de tecido/mL) e o terceiro utilizando 0.5% (v/v) de
Alcalase (HPPcom), uma enzima comercial. Os extratos experimentais revelaram a presença de
proteases totaias, tripsina, quimotripsina e leucinoaminopeptidase. O teor de proteínas,
aminoácidos e ácidos graxos foram calculados em matéria seca. Depois de 4 horas de reação,
o grau de hidrolise máximo (GH) do HPPcom, HPP100, HPP600 foram 34.73 ± 1.44%, 29.21 ±
0.79%, e 41.66 ± 1.33%, respectivamente. O perfil eletroforetico demonstrou bandas de 190 a
20 kDa (HPP100), 54 kDa (HPPcom) e 53 a 20 kDa (HPP600). O resultados dos teores proteicos
foram, 584.8 g/kg, 492.3 g/kg, e 508.2 g/kg para HPPcom, HPP100, e HPP600, respectivamente.
Metionina e lisina foram identificados em níveis de 32.0 e 77.0 g/kg (HPPcom), 31.0 e 64.0
g/kg (HPP100), e 33.0 e 69.0 g/kg (HPP600), respectivamente. O conteúdo de ácidos graxos
polisanturados do HPPcom, HPP100 e HPP600 foram 101.0 g/kg, 138.0 g/kg e 70 g/kg,
respectivamente, com predominância do ácido linoleico (C18:2n-6). O valor do IAAI foi de
1066.07, 688.4 e 738.51 no HPPcom, HPP100 e HPP600, respectivamente. A composição de
aminoácidos, perfil lipídico e escore químico sugerem que todos os HPPs testados podem ser
empregados como fonte proteica em dietas para organismos aquáticos. O segundo estudo
comparou a eficiência de enzimas do intestino de tilápia (200 mg de tecido/mL) bruto e
parcialmente purificados por precipitação salina (0 – 80%, v/v) e etanólica (0-30%, v/v), (30 –
70%, v/v) com duas enzimas comerciais Alcalase 0.5% (v/v) e Flavourzyme 0.5% (v/v) na
hidrolise da carcaça da tilápia. O extrato enzimático semi-purificado com (NH4)2SO4 mostrou
rendimento de 62.6% (ativ. esp. de 9.3 U/mg de tecido) e com etanol um rendimento de
42.6% (ativ. esp. de 37.0 U/mg de tecido) e 68.4% (33.9 U/mg de tecido). Após 4 horas de
reação o HPPEC(200) mostrou maior GH (37.8%), seguidos por HPPA (35.3%), HPPET (33.2%),
HPPAS (24.6%) e HPPF (18.5%). O perfil eletroforético demosntrou que o peso molecular dos
HPPs variaram entre 116.25 a 29.05 KDa. O extrato bruto e os extratos semi-purificados
foram mais eficientes na hidrolise da carcaça de tilápia que a enzima comercial Flavourzime.
O terceiro estudo testou os efeitos da esterilização térmica, acidificação e irradiação na
conservação de HPP. Foram realizadas análises físico-quimicas (TBARS, pH, composição
centesimal), microbiológicas (mesófilos, piscicrófilos e microorganismos específicos) e
sensorial (coloração) durante 60 dias. As análises mostraram que os HPPs possuem alto teor
proteico e lipídico e são susceptíveis a mudanças de pH, oxidação lipídica e descoloração. A
partir do décimo dia de estocagem todos os HPPs tiveram teores de TBARS aumentados e
sofreram descoloração. O conteúdo proteico e lipídico foi alterado, mas não comprometeu o
valor nutricional dos HPPs. A esterilização térmica com adição de ácidos e esterlização por
irradiação foram eficientes na à eliminação dos microorganismos garantindo a segurança do
produto por 60 dias de armazenamento. No quarto trabalho obteve-se uma patente referente à
separação da parte lipídica da proteica do hidrolisado proteico de peixe a partir da irradiação. / Fish viscera and carcasses represent about 70% of body weight of tilapia (Oreochromis
nilotic), and are known sources of biomolecules such as protein and proteases. These enzymes
can be employed in various biotechnological processes, e.g. preparation of fish protein
hydrolysates. In this way, the aims of the first study were to evaluate the use of processing
waste from Nile tilapia (Oreochromis niloticus) as a source of protein and proteases to
produce FPH. Three FPH production conditions were evaluated: two conditions used
autolysis with enzymes extracted from the tilapia intestine at different concentrations (FPH100,
100 mg of tissue/mL and FPH600, 600 mg of tissue/mL) and the third used 0.5% (v/v)
Alcalase (FPHcom), a commercial protease preparation. The experimentais extracts showed
total proteolytic activities, trypsin, chymotrypsin, and leucine aminopeptidase activities
proteases. Protein, amino acids and fatty acids content were calculated as DM basis. After a 4-
h reaction, maximum hydrolysis percentages (DH) from FPHcom, FPH100, and FPH600 systems
were 34.73 ± 1.44%, 29.21 ± 0.79%, and 41.66 ± 1.33%, respectively. The protein content in
the resulting FPS were 584.8 g/kg, 492.3 g/kg, and 508.2 g/kg for FPHcom, FPH100, and
FPH600, respectively. Methionine and lysine were found at levels of 32.0 and 77.0 g/kg
(FPHcom), 31.0 and 64.0 g/kg (FPH100), and 33.0 and 69.0 g/kg (FPH600), respectively.
Polyunsaturated fatty acid contents of FPHcom, FPH100, and FPH600 were 101.0 g/kg, 138.0
g/kg, and 70 g/kg, respectively, with a predominance of linoleic acid (C18:2n-6). IAAI
reached a value of 1066.07 in FPHcom, 688.4 in FPH100 and 738.51 in FPH600. Amino acid
composition, lipid profile, and amino acid score suggested that all of the experimental FPHs
could be employed as a protein source in diets for aquatic organisms and other farmed
animals. The second study compared the efficiency of the enzymes from tilapia intestine (200
mg tissue/mL) crude and partially purified by salting-in (0 - 80% v/v) and ethanol (0-30%,
v/v), (30 - 70% v/v) with two commercial enzymes Alcalase 0.5% (v/v) and 0.5%
Flavourzyme (v/v) hydrolysis of the carcass tilapia. The partial purified enzyme extract with
(NH4)2SO4 showed a yield of 62.6% (act. esp. of 9.3 U/mg of tissue) and ethanol a yield of
42.6% (act. esp. of 37.0 U/mg tissue ) and 68.4% (33.9 U/mg tissue). After 4 hours the
reaction, FPHEC (200) showed a higher DH (37.8%), followed by FPHA (35.3%), FPHET
(33.2%), FHPAS (24.6%) and FPHF (18.5%). The electrophoretic profile of FPHs showed
molecular weight ranged from 116.25 to 29.05 kDa. The crude extract and partial purified
extracts were more effective in the hydrolysis of tilapia carcasses than commercial enzyme
Flavourzime. The third study tested the effects of heat sterilization, irradiation and
acidification in the conservation of FPH. They were carried out physical-chemical analysis
(TBARS, pH, chemical composition), microbiological (mesophilic, piscicrophilic and specific
microorganisms) and sensorial (color) for 60 days. Analyzes have shown that FPHs have high
protein and lipid content and FPHs are susceptible to changes in pH, lipid oxidation and
discoloration. From the 10th day of storage all FPH had increased TBARS levels and
discoloration. The protein and lipid content has changed, but did not compromise the
nutritional value of FPHs. Heat treatment with citric acid and gamma irradiation were
effective in the removal of microorganisms pathogenic securing of the product for 60 days of
storage. In the fourth work we obtained a patent for the separation of the lipid portion of the
protein fish protein hydrolyzate from the irradiation.
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Production et purification d'acide férulique estérases. Application à la synthèse d'esters phénoliques / Production and purification of ferulic acid esterases. Application to the synthesis of phenolic estersKheder, Fadi 25 October 2007 (has links)
L’induction de la synthèse d’une acide férulique estérase (AFE) a été étudiée chez Streptomyces ambofaciens ATCC 23877. L’activité la plus élevée a été détectée en présence de son de blé désamidonné ou de xylane d’avoine (0,22, 0,21 mU/mg protéine, respectivement). Des productions d’AFE en bioréacteur ont également été réalisées en utilisant 1% (p/v) de son de blé comme inducteur. Le niveau de production de l’AFE a été trois fois plus important en bioréacteur qu’en fiole d’Erlenmeyer. L’AFE de Streptomyces ambofaciens ATCC 23877 et celle de Humicola sp., présente dans un mélange enzymatique commercial (DepolTM 740L), ont été partiellement purifiées et caractérisées. A l’issue de la purification, l’activité AFE de Streptomyces ambofaciens ATCC 23877 a été trop faible pour pouvoir être utilisée ultérieurement en synthèse. Par contre, le potentiel de l’AFE de Humicola sp., concentrée par précipitation à l’acétone, pour la synthèse de différents esters phénoliques a été testé. Les meilleurs rendements de conversion ont été observés lors de l’absence de substitutions sur le cycle aromatique de l’acide phénolique ou en présence de groupements hydroxyles. Les synthèses en milieu non aqueux (M2B2) se sont montrées infructueuses en raison, peut-être, d’un effet néfaste du solvant sur l’enzyme / The induction of the ferulic acid esterase (FAE) synthesis was studied with Streptomyces ambofaciens ATCC 23877. The highest activity was detected in the presence of either destarched wheat bran or oat spelt xylan (0,22, 0,21 mU/mg protein, respectively). FAE productions in bioreactor were also carried out using 1% (w/v) of wheat bran as inducer. The FAE production level was three times higher in bioreactor than in Erlenmeyer flask. FAE of Streptomyces ambofaciens ATCC 23877 and that of Humicola sp., present in an enzymatic commercial mixture (DepolTM 740L), were partially purified and characterised. At the end of the purification, FAE activity of Streptomyces ambofaciens ATCC 23877 was too weak to be used later in synthesis. However, the FAE potential of Humicola sp., concentrated by acetone precipitation, for the synthesis of various phenolic esters was tested. The best conversion yields were observed in the absence of substitution on the phenolic acid aromatic cycle or in the presence of hydroxyl groups. The synthesis in non-aqueous medium (M2B2) were unsuccessful maybe because of an harmful effect of the solvent on the enzyme
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