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Determination of amino acids by capillary electrophoresis-electrospray ionization-mass spectrometry: An evaluation of different protein hydrolysis procedures

SIMIONATO, Ana V. Colnaghi; MORAES, Edgar Perin; CARRILHO, Emanuel; TAVARES, Marina Franco Maggi; KENNDLER, Ernst
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
ENG
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46.04%
In this work, a CE equipment, online hyphenated to an IT MS analyzer by a linear sheath liquid interface promoting ESI, was used to develop a method for quantitative determination of amino acids. Under appropriate conditions (BGE composition, 0.8% HCOOH, 20% CH(3)OH; sheath liquid composition, 0.8% HCOOH, 60% methanol; V(ESI), +4.50 W), analytical curves of all amino acids from 3 to 80 mg/L were recorded presenting acceptable linearity (r > 0.99). LODs in the range of 16-172 mu mol/L were obtained. BSA, a model protein, was submitted to different hydrolysis procedures (classical acid and basic, and catalyzed by the H(+) form of a cation exchanger resin) and its amino acid profiles determined. In general, the resin-mediated hydrolysis yields were overall similar or better than those obtained by classical acid or basic hydrolysis. The resulting experimental-to-theoretical BSA concentration ratios served as correction factors for the quantitation of amino acids in Brazil nut resin generated hydrolysates.

Prediction of apparent protein digestibility of ingredients and diets by in vitro pH-stat degree of protein hydrolysis with species-specific enzymes for juvenile Pacific white shrimp Litopenaeus vannamei

LEMOS, D.; LAWRENCE, A. L.; III, A. J. Siccardi
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
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Aquafeed production faces global issues related to availability of feed ingredients. Feed manufacturers require greater flexibility in order to develop nutritional and cost-effective formulations that take into account nutrient content and availability of ingredients. The search for appropriate ingredients requires detailed screening of their potential nutritional value and variability at the industrial level. In vitro digestion of feedstuffs by enzymes extracted from the target species has been correlated with apparent protein digestibility (APD) in fish and shrimp species. The present study verified the relationship between APD and in vitro degree of protein hydrolysis (DH) with Litopenaeus vannamei hepatopancreas enzymes in several different ingredients (n = 26): blood meals, casein, corn gluten meal, crab meal, distiller`s dried grains with solubles, feather meal, fish meals, gelatin, krill meals, poultry by-product meal, soybean meals, squid meals and wheat gluten. The relationship between APD and DH was further verified in diets formulated with these ingredients at 30% inclusion into a reference diet. APD was determined in vivo (30.1 +/- 0.5 degrees C, 32.2 +/- 0.4%.) with juvenile L vannamei (9 to 12 g) after placement of test ingredients into a reference diet (35 g kg(-1) CP: 8.03 g kg(-1) lipid; 2.01 kcal g(-1)) with chromic oxide as the inert marker. In vitro DH was assessed in ingredients and diets with standardized hepatopancreas enzymes extracted from pond-reared shrimp. The DH of ingredients was determined under different assay conditions to check for the most suitable in vitro protocol for APD prediction: different batches of enzyme extracts (HPf5 or HPf6)...

Prediction of culture performance of juvenile Litopenaeus vannamei by in vitro (pH-stat) degree of feed protein hydrolysis with species-specific enzymes

LEMOS, D.; NUNES, A. J. P.
Fonte: BLACKWELL PUBLISHING Publicador: BLACKWELL PUBLISHING
Tipo: Artigo de Revista Científica
ENG
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Rapid in vitro methods for measuring digestibility may be useful in analysing aqua feeds if the extent and limits of their application are clearly defined. The pH-stat protein digestibility routine with shrimp hepatopancreas enzymes was previously related to apparent protein digestibility with juvenile Litopenaeus vannamei fed diets containing different protein ingredients. The potential of the method to predict culture performance of shrimp fed six commercial feeds (T3, T4, T5, T6, T7 and T8) with 350 g kg(-1) declared crude-protein content was assessed. The consistency of results obtained using hepatopancreas enzyme extracts from either pond or clear water-raised shrimp was further verified in terms of reproducibility and possible diet history effects upon in vitro outputs. Shrimps were previously acclimated and then maintained over 56 days (initial mean weight 3.28 g) on each diet in 500-L tanks at 114 ind m(-2), clear water closed system with continuous renewal and mechanical filtering (50 mu m), with four replicates per treatment. Feeds were offered four times daily (six days a week) delivered in trays at feeding rates ranging from 4.0% to 7.0% of stocked shrimp biomass. Feed was accessible to shrimp 4 h daily for 1-h feeding period after which uneaten feed was recovered. Growth and survival were determined every 14 days from a sample of 16 individuals per tank. Water quality was monitored daily (pH...

Digestão in vitro de proteína e fósforo utilizando enzimas digestivas espécie-específicas: potencial de desenvolvimento e aplicação para a aquicultura de espécies de peixes; In vitro digestion of protein and phosphorus with species-specific digestive enzymes: potential for method development and application in the aquaculture of fish species

Yasumaru, Fanny Ayumi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 09/10/2014 PT
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Esta tese teve como objetivo o desenvolvimento de método in vitro pH-stat com enzimas espécie-específicas, avaliando a digestão de proteína (PB) e fósforo (P) em peixes, para prever a digestibilidade in vivo. As espécies utilizadas como modelos experimentais foram a truta arco-íris, Oncorhynchus mykiss, o bijupirá, Rachycentron canadum e a tilápia-do-Nilo, Oreochromis niloticus. Extratos enzimáticos foram obtidos de estômago, cecos pilóricos (truta e bijupirá) ou intestino (tilápia) de indivíduos de diferentes tamanhos e estado alimentar. A capacidade hidrolítica das enzimas foi padronizada utilizando substratos protéicos de grau analítico por meio da determinação do grau de hidrólise protéica (DH) em ensaio pH-stat. Ingredientes práticos foram hidrolisados com extrato enzimático de (i) estômago, (ii) cecos pilóricos (truta e bijupirá)/intestino (tilápia) ou (iii) estômago seguido de cecos pilóricos/intestino (dupla hidrólise) para determinar os valores de DH. O método de determinação de DH apresenta baixo coeficiente de variação, e pode ser uma ferramenta útil no ranqueamento e no controle de qualidade de ingredientes práticos. O P solúvel liberado de amostras de nove rações comerciais para tilápia...

Protein Hydrolysis by Immobilized and Stabilized Trypsin

Marques, Daniela; Pessela, Benavides C.; Betancor, Lorena; Monti, Rubens; Carrascosa, Alfonso V.; Rocha-Martin, Javier; Guisan, Jose M.; Fernandez-Lorente, Gloria
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 677-683
ENG
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The preparation of novel immobilized and stabilized derivatives of trypsin is reported here. The new derivatives preserved 80% of the initial catalytic activity toward synthetic substrates [benzoyl-arginine p-nitroanilide (BAPNA)] and were 50,000-fold more thermally stable than the diluted soluble enzyme in the absence of autolysis. Trypsin was immobilized on highly activated glyoxyl-Sepharose following a two-step immobilization strategy: (a) first, a multipoint covalent immobilization at pH 8.5 that only involves low pK(a) amino groups (e. g., those derived from the activation of trypsin from trypsinogen) is performed and (b) next, an additional alkaline incubation at pH 10 is performed to favor an intense, additional multipoint immobilization between the high concentration of proximate aldehyde groups on the support surface and the high pK(a) amino groups at the enzyme surface region that participated in the first immobilization step. Interestingly, the new, highly stable trypsin derivatives were also much more active in the proteolysis of high molecular weight proteins when compared with a nonstabilized derivative prepared on CNBr-activated Sepharose. In fact...

Secagem de hidrolisado protéico de pele de cação por atomização : otimização do processo de hidrólise e avaliação das características físico-químicas do pó; Spray drying of shark protein hydrolysate : hydrolysis process optimization and evaluation of the physicochemical powder characteristics

Julio César Rodríguez Díaz
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/02/2011 PT
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O presente trabalho teve como objetivo a obtenção de hidrolisado protéico de pele de cação em pó pelos processos de hidrólise enzimática e secagem por atomização. Na primeira etapa, foi estudado o processo de hidrólise utilizando a enzima comercial ProtamexTM, visando a otimização do processo para a recuperação de peptídeos de baixo peso molecular. A influência da temperatura, do pH e da relação Enzima/Substrato sobre o grau de hidrólise, recuperação de proteína e cinética enzimática foram avaliadas. As condições ótimas de processo foram fixadas em: 51 °C, 4,0% p/p de enzima e pH 7,1. Nessas condições, o hidrolisado obtido foi caracterizado em termos de composição química, composição de aminoácidos e distribuição de tamanho de peptídeo. O grau de hidrólise atingiu 19,3%, recuperou-se 90,3% do total da proteína presente na matéria-prima e o peso molecular foi inferior a 6,5 kDa. Na segunda etapa do projeto, foi avaliada a influência das variáveis do processo de secagem por atomização sobre as propriedades físico-químicas e antioxidantes do hidrolisado protéico de pele de cação em pó, usando maltodextrina (DE=10) como agente carreador. A temperatura do ar e a concentração de agente carreador foram variadas. As respostas analisadas foram a umidade final...

Atividade antioxidante de produtos proteicos de linhaça (Linum usitatissimum L.); Antioxidante activity of flaxseed protein products (Linum usitatissimum L.)

Fernanda Guimarães Drummond e Silva
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 12/04/2012 PT
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Existem evidências numerosas sobre o papel dos radicais livres em uma série de condições patológicas, incluindo envelhecimento, câncer, esclerose múltipla, doenças cardiovasculares. Hidrolisados protéicos de diferentes fontes têm sido estudados por seu potencial antioxidante. A atuação antioxidante da proteína, na maioria das vezes, encontra-se limitada devido à conformação espacial, que concentra resíduos capazes de neutralizar radicais livres no interior da molécula, dificultando o acesso das espécies reativas aos centros nucleofílicos. A hidrólise da proteína contribui para aumentar a exposição desses resíduos de aminoácidos, aumentando sua atuação como antioxidante. Compostos fenólicos podem estar presentes em hidrolisados proteicos de origem vegetal, devido a sua associação com as proteínas. Métodos in vitro que simulam as condições do trato gastrointestinal permitem estudar como a digestão pode interferir na atividade antioxidante de peptídeos e compostos fenólicos. O presente trabalho tem como objetivos obter hidrolisados proteicos com capacidade antioxidante a partir da farinha de linhaça e avaliar o efeito da digestão in vitro pode interferir nessa atividade. A farinha de linhaça marrom foi desengordurada...

Rheological and structural characterization of gels from whey protein hydrolysates/locust bean gum mixed systems

Rocha, Cristina M. R.; Teixeira, J. A.; Hilliou, L.; Sampaio, Paula; Gonçalves, M. P.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /10/2009 ENG
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The gelling ability of whey proteins can be changed by limited hydrolysis and by the addition of other components such as polysaccharides. In this work the effect of the concentration of locust bean gum (LBG) on the heat-set gelation of aqueous whey protein hydrolysates (10% w/w) from pepsin and trypsin was assessed at pH 7.0. Whey protein concentrate (WPC) mild hydrolysis (up to 2.5% in the case of pepsin and 1.0% in the case of trypsin) ameliorates the gelling ability. The WPC synergism with LBG is affected by the protein hydrolysis. For a WPC concentration of 10% (w/w), no maximum value was found in the G′ dependence on LBG content in the case of the hydrolysates, unlike the intact WPC. However, for higher protein concentrations, the behaviour of gels from whey proteins or whey protein hydrolysates towards the presence of LBG becomes very similar. In this case, a small amount of LBG in the presence of salt leads to a big enhancement in the gel strength. Further increases in the LBG concentration led to a decrease in the gel strength.

Immobilization of trypsin on spent grains for whey protein hydrolysis

Rocha, Cristina M. R.; Gonçalves, M. P.; Teixeira, J. A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2011 ENG
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The aims of this work were to establish an efficient protocol for trypsin immobilization on spent grains and to assess the influence of the chosen protocol on whey protein hydrolysis. Trypsin was immobilized onto spent grain or modified spent grain, through adsorption and covalent attachment. The efficiency of immobilization and operation and storage stabilities of free and immobilized enzyme on the supports were studied. The enzyme activity, kinetic parameters and the peptide profile of the protein hydrolysates from free and immobilized enzyme were also analysed. The best activity retention was achieved with the immobilization on spent grains through multipoint covalent attachment using glycidol. This carrier showed also very good storage and operational stability (above 90%). Trypsin immobilized on spent grains showed significant activity towards whey proteins. The immobilized enzyme was slightly more stable than the free enzyme at temperatures between 50 °C and 60 °C allowing its use at a broader range of temperatures. The peptides formed with free enzyme and enzyme immobilized on spent grains were generally similar. However, significant differences existed in the amount of native proteins in the hydrolysates and in the relative amount of smaller peptides.

Controlled whey protein hydrolysis using two alternative proteases

Pintado, Manuela E.; Pintado, Ana E.; Malcata, F. Xavier
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //1999 ENG
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Whole whey was hydrolyzed for 12 h with Protease 2A and Trypsin using two concentrations of enzyme (20 and 40 g/kgprotein). Samples were assayed for total viable counts of adventitious microflora that survived thermization, total acidity, total concentration of free amino acids, peptide profile and overall degree of hydrolysis. The highest total concentration of free amino acids was observed when hydrolysis was effected by Protease 2A, and the major variations in amino acid qualitative composition occurred between 2 and 6 h: Leu exhibited the most significant increase, followed by Lys, Phe and Ile. Hydrolysis with Trypsin led to release of high amounts of Lys. Quantitative depletion of β-lactoglobulin was observed by 2 h under all processing conditions, and hydrolysis of α-lactalbumin was slower when Trypsin was employed. Formation of peptides was more extensive under the action of Trypsin than of Protease 2A, and the major peptides released by the former had molecular weights mainly in the ranges 7500–8000 and 4000–4500 Da, whereas those released by the latter accumulated in the range 7000–7500 Da. The differences between the hydrolytic actions of Trypsin and Protease 2A were significant except with respect to the concentration of Glu...

Kinetic model for whey protein hydrolysis by alcalase multipoint-immobilized on agarose gel particles

Sousa Jr,R.; Lopes,G. P.; Tardioli,P. W.; Giordano,R. L. C.; Almeida,P. I. F.; Giordano,R.C.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2004 EN
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Partial hydrolysis of whey proteins by enzymes immobilized on an inert support can either change or evidence functional properties of the produced peptides, thereby increasing their applications. The hydrolysis of sweet cheese whey proteins by alcalase, which is multipoint-immobilized on agarose gel, is studied here. A Michaelis-Menten model that takes into account competitive inhibition by the product was fitted to experimental data. The influence of pH on the kinetic parameters in the range 6.0 to 11.0 was assessed, at 50ºC. Initial reaction-rate assays in a pHstat at different concentrations of substrate were used to estimate kinetic and Michaelis-Menten parameters, k and K M. Experimental data from long-term batch assays were used to quantify the inhibition parameter, K I. The fitting of the model to the experimental data was accurate in the entire pH range.

Use of a proteolytic enzyme in cocoa (Theobroma cacao L.) processing

Brito,Edy Sousa de; Pezoa García,Nelson Horacio; Amancio,Allan César
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2004 EN
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Protein hydrolysis using an exogenous protease on cocoa nibs was performed to verify the formation of precursors and the effect on cocoa flavour. An experimental design was used to check the influence of temperature (30 to 70 ºC) and enzyme : substrate ratio [E/S] (97.5 to 1267.5 U g-1 of protein). The % Degree of Hydrolysis (% DH) was affected mainly by [E/S] leading to a 4-fold increase (from 5 to 20 %) after 6 hours of treatment. During cocoa nibs roasting, there was a greater consumption of hydrolysis compounds in the sample treated with protease as compared to the control, indicating their participation in the Maillard reaction. An increased perception of chocolate flavour and bitter taste was observed in a product formulated with protease treated cocoa.

Physiological Control of Exo- and Endoproteolytic Activities in Germinating Wheat and Their Relationship to Storage Protein Hydrolysis 1

Preston, Ken R.; Kruger, James E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1979 EN
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46.1%
The effects of gibberellic acid, abscisic acid, cycloheximide, actinomycin D, and cordycepin upon exo- and endoproteolytic activities and storage (gluten) protein hydrolysis in germinating wheat and in incubated embryoless wheat seeds have been studied. Early increases in endoproteolytic activity were insensitive to the addition of gibberellic acid and inhibitors of protein and RNA synthesis. Later increases in endoproteolytic activity were enhanced by gibberellic acid, strongly inhibited by abscisic acid and cycloheximide, and partially inhibited by actinomycin D and cordycepin. Increases in exoproteolytic activity were insensitive to the addition of gibberellic acid, abscisic acid, actinomycin D, and cordycepin but were inhibited in whole seeds when cycloheximide was added in the steeping medium. However, cycloheximide did not inhibit increases in exoproteolytic activity when added to embryoless seeds, to germinating whole seeds, or to seeds which had been stored at 4 C for extended periods of time. Comparison of the effects of gibberellic acid, abscisic acid, and inhibitors of protein and RNA synthesis upon storage protein hydrolysis and their effects upon proteolytic activity indicated that storage protein hydrolysis in germinating wheat is controlled by the rate of hormonally induced de novo synthesis of endoproteolytic enzymes.

P138-T Microwave-Assisted Protein Hydrolysis

Ingle, E. S.; Lill, J. R.
Fonte: The Association of Biomolecular Resource Facilities Publicador: The Association of Biomolecular Resource Facilities
Tipo: Artigo de Revista Científica
Publicado em /02/2007 EN
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56.1%
Introduction: Protein hydrolysis is the process by which peptide bonds are broken under acidic conditions at high temperatures, generating free amino acid residues. The resulting hydrolysates can then be analyzed by amino acid analysis to determine the amino acid composition and concentration of proteins. The hydrolysis procedure is the rate-limiting step for amino acid analysis. Microwave-assisted protein hydrolysis offers the potential to reduce hydrolysis time significantly.

Characterization of the Recombinant Exopeptidases PepX and PepN from Lactobacillus helveticus ATCC 12046 Important for Food Protein Hydrolysis

Stressler, Timo; Eisele, Thomas; Schlayer, Michael; Lutz-Wahl, Sabine; Fischer, Lutz
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 19/07/2013 EN
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46%
The proline-specific X-prolyl dipeptidyl aminopeptidase (PepX; EC 3.4.14.11) and the general aminopeptidase N (PepN; EC 3.4.11.2) from Lactobacillus helveticus ATCC 12046 were produced recombinantly in E. coli BL21(DE3) via bioreactor cultivation. The maximum enzymatic activity obtained for PepX was 800 µkatH-Ala-Pro-pNA L−1, which is approx. 195-fold higher than values published previously. To the best of our knowledge, PepN was expressed in E. coli at high levels for the first time. The PepN activity reached 1,000 µkatH-Ala-pNA L−1. After an automated chromatographic purification, both peptidases were biochemically and kinetically characterized in detail. Substrate inhibition of PepN and product inhibition of both PepX and PepN were discovered for the first time. An apo-enzyme of the Zn2+-dependent PepN was generated, which could be reactivated by several metal ions in the order of Co2+>Zn2+>Mn2+>Ca2+>Mg2+. PepX and PepN exhibited a clear synergistic effect in casein hydrolysis studies. Here, the relative degree of hydrolysis (rDH) was increased by approx. 132%. Due to the remarkable temperature stability at 50°C and the complementary substrate specificities of both peptidases, a future application in food protein hydrolysis might be possible.

Enzymatic hydrolysis of heat-denatured whey proteins

O'Loughlin, Ian B.
Fonte: University of Limerick Publicador: University of Limerick
Tipo: info:eu-repo/semantics/doctoralThesis; all_ul_research; ul_published_reviewed; ul_theses_dissertations
ENG
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peer-reviewed; The heat-treatment of whey proteins in conjunction with enzymatic hydrolysis has potential in the development of new, or modification of existing, processes for technoand bio-functional whey protein ingredient production. Selective heat-treatment of fractions enriched in individual whey proteins and whey protein isolate (WPI) demonstrated differences in both their aggregation behaviour and subsequent susceptibility to enzymatic hydrolysis. This was examined at both a sub-molecular and macro-molecular level where whey protein samples were hydrolysed to varying degrees of hydrolysis (DH). The individual whey protein components were susceptible to denaturation on thermal treatment in the following order; β-lg A > β-lg B > α-la > CMP. The heat pre-treated substrates, which exhibited increased viscosity and surface hydrophobicity, demonstrated significantly increased (P < 0.001) rates of hydrolysis with the pancreatic enzymatic preparation, Corolase® PP. The proteinaceous components were hydrolysed in the order; CMP > β-lg A > β-lg B > α- la. The hydrolysates (5 %DH) had an increase in soluble molecular weight (Mw) material greater than 30 kDa which was shown to be peptides mainly derived from the 1Leu-Arg40...

A new method for protein hydrolyisis with crystallized oxalic acid

Iachan, Abrahão; Disitzer, L. V.; Perrone, J. C.
Fonte: Instituto Nacional de Tecnologia Publicador: Instituto Nacional de Tecnologia
Tipo: Artigo de Revista Científica
EN
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45.91%
Anais. da Academia Brasileira de Ciências, 33(2):169-172 , 30 junho 1961. separata.; The well known disadvantages of the conventional methods of protein hydrolysis prompted us to try "dry heating" of the protein with crystallized oxalic acid as hydrolyzing agent.

Production of lupinus angustifolius protein hydrolysates with improved functional properties; Producción de hidrolizados proteicos de Lupinus angustifolius con mejores propiedades funcionales

Lqari, Hassane; Pedroche, Justo; Girón-Calle, Julio; Vioque, Javier; Millán, Francisco
Fonte: Consejo Superior de Investigaciones Científicas (España) Publicador: Consejo Superior de Investigaciones Científicas (España)
Tipo: Artículo
ENG
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46.1%
Protein hydrolysates were obtained from lupin flour and from the purified globulin a-conglutin, and their functional properties were studied. Hydrolysis with alcalase for 60 minutes yielded degrees of hydrolysis ranging from 4% to 11% for lupin flour, and from 4% to 13% for a-conglutin. Protein solubility, oil absorption, foam capacity and stability, emulsifying activity, and emulsion stability of hydrolysates with 6% degree of hydrolysis were determined and compared with the properties of the original flour. The protein hydrolysates showed better functional properties than the original proteins. Most impor tantly, the solubility of the a-conglutin and L. angustifolius flour hydrolysates was increased by 43% and 52%, respectively. Thus, lupin seed protein hydrolysates have improved functional properties and could be used in the elaboration of a variety of products such as breads, cakes, and salad dressings.; Se obtuvieron hidrolizados proteicos de la harina del altramuz y de la globulina α-conglutina purificada y se estudiaron sus propiedades funcionales. La hidrólisis con alcalasa durante 60 minutos produjo hidrolizados con grados de hidrólisis entre el 4 % y el 11 % para la harina y entre el 4 % y el 13 % para la α-conglutina. Se estudió en un hidrolizado con un 6 % de grado de hidrólisis la solubilidad proteica...

Characterization of muscle sarcoplasmic and myofibrillar protein hydrolysis caused by Lactobacillus plantarum

Fadda, Silvina; Sanz, Yolanda; Vignolo, Graciela; Oliver, Guillermo; Toldrá Vilardell, Fidel
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artículo Formato: 1951687 bytes; 2459 bytes; application/pdf; text/plain
ENG
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56.07%
Strains of Lactobacillus plantarum originally isolated from sausages were screened for proteinase and aminopeptidase activities toward synthetic substrates; on the basis of that screening, L. plantarum CRT, 681 was selected for further assays on muscle proteins. The activities of whole cells, cell extracts (CE), and a combination of both on sarcoplasmic and myofibrillar protein extracts were determined by protein, peptide, and free-amino-acid analyses. Proteinase from whole cells initiated the hydrolysis of sarcoplasmic proteins. The addition of CE intensified the proteolysis. Whole cells generated hydrophilic peptides from both sarcoplasmic and myofibrillar proteins. Other peptides of a hydrophobic nature resulted from the combination of whole cells and CE, The action of both enzymatic sources on myofibrillar proteins caused maximal increases in lysine, arginine, and leucine, while the action of those on sarcoplasmic proteins mainly released alanine, In general, pronounced hydrolysis of muscle proteins required enzyme activities from whole cells in addition to those supplied by CE.; grant ALI98-0890 from Comisión Interministerial de Ciencia y Tecnología (CICYT, Madrid, Spain)

Utilization of fisheries by-catch and processing wastes for lactic acid fermented silage and evaluation of degree of protein hydrolisis and in vitro digestibility

Ramírez- Ramírez,J. C.; Huerta,S.; Arias,L.; Prado,A.; Shirai,K.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2008 EN
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55.95%
The purpose of this study was to produce protein hydrolysates from lactic acid fermentation of three sources of fish wastes: Shrimp by catch (SC), Sphyraena ensis wastes (SB) and mixture of fisheries processing wastes from several species (MixW). MixW were added with several sugar cane molasses concentrations as the carbon source, 180 g.kg-1 of sugar molasses gave the fastest acidification. The maximum concentration of lactic acid (Pmax) was significantly higher with Lactobacillus sp. B2 than that obtained with Lb. plantarum. MixW was selected for scaling up and inoculated with Lactobacillus sp. B2 due to the enhanced lactic acid production and availability. According to microbiological and chemical analyses, the fermented product was well preserved due to the acid produced and the reduction in aW (0.94) that inhibit spoilage microorganisms and putrefaction. The coefficient of protein hydrolysis at 144 h of fermentation was significantly higher (0.94) than the obtained with raw MixW (0.12). The coefficient of protein in vitro digestibility (CPD) was also determined, which was higher, 0.88, than raw MixW (0.69).