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1.
Food Chem ; 458: 140159, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38959804

RESUMEN

A selection of formulations with different polymers and concentrations of green tea extract was conducted for application as interleafs in sliced meat products. Films were formulated using cellulose acetate, corn starch, and chitosan with the addition of 1.0, 2.5, and 5.0% green tea extract. Higher antioxidant activity was observed with the 1.0% concentration of green tea extract (P < 0.05), regardless of the formulation, with continuous release of the extract for up to 60 days and average IC50 of 0.09 and 0.31 mg/mL for the corn starch and chitosan active films, respectively. Interleafing the sliced ham resulted in lower lipid oxidation after 60 days of storage (P < 0.05). Starch-based films with green tea extract were effective, significantly reducing lipid oxidation in sliced and interleafed cooked ham, suggesting their potential to extend the shelf life of these refrigerated products.

2.
Clin Nutr ESPEN ; 59: 154-157, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38220369

RESUMEN

BACKGROUND & AIMS: This study is based on the development and validation of a popsicle to reduce preoperative fasting time. METHODS: The study was carried out in two stages, pre-clinical and clinical validation. The first stage consisted of producing a water-based, fat-free, high-calorie fruit-flavored popsicle, characterized by proximal composition and sensory analysis. In the second stage, clinical validation was performed in patients aged between 18 and 65 years before elective surgery, evaluating the incidence of aspiration during anesthesia and the patient's experience in relation to hunger, thirst, anxiety and palatability of the popsicle. RESULTS: The results of the study showed that the use of popsicle 2 h before the surgical procedure did not cause any adverse reaction in patients and in the anesthetic procedure. Furthermore, the full acceptability of the product by the participants and the control of thirst and satiety during the preoperative period were observed. CONCLUSIONS: The present study showed that with the use of popsicles it was possible to reduce safely the preoperative fasting time to up to 2 h before the surgical procedure.


Asunto(s)
Ayuno , Cuidados Preoperatorios , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Cuidados Preoperatorios/métodos , Hambre , Sed , Frutas
3.
3 Biotech ; 14(1): 32, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38188310

RESUMEN

The objective of this study was to purify sodium maltobionate using Zymomonas mobilis cells immobilized in situ on flexible polyurethane (PU) and convert it into maltobionic acid for further evaluation of bioactivity (iron chelating ability, antibacterial potential and cytoprotection) and incorporation into films based on cassava starch, chitosan, and cellulose acetate. Sodium maltobionate exhibited a purity of 98.1% and demonstrated an iron chelating ability of approximately 50% at concentrations ranging from 15 to 20 mg mL-1. Maltobionic acid displayed minimal inhibitory concentrations (MIC) of 8.5, 10.5, 8.0, and 8.0 mg mL-1 for Salmonella enterica serovar Choleraesuis, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes, respectively. Maltobionic acid did not exhibit cytotoxicity in HEK-293 cells at concentrations up to 500 µg mL-1. Films incorporating 7.5% maltobionic acid into cassava starch and chitosan demonstrated inhibition of microbial growth, with halo sizes ranging from 15.67 to 22.33 mm. These films had a thickness of 0.17 and 0.13 mm, water solubility of 62.68% and 78.85%, and oil solubility of 6.23% and 11.91%, respectively. The cellulose acetate film exhibited a non-uniform visual appearance due to the low solubility of maltobionic acid in acetone. Mechanical and optical properties were enhanced with the addition of maltobionic acid to chitosan and cassava films. The chitosan film with 7.5% maltobionic acid demonstrated higher tensile strength (30.3 MPa) and elongation at break (9.0%). In contrast, the cassava starch film exhibited a high elastic modulus (1.7). Overall, maltobionic acid, with its antibacterial activity, holds promise for applications in active films suitable for food packaging. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03879-3.

4.
Food Technol Biotechnol ; 61(3): 312-327, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38022879

RESUMEN

Cynara cardunculus L. var. scolymus, known as the artichoke, originated in the Mediterranean region and is now cultivated in several countries. The artichoke has leaves, a stem, and a head, also called a floral capitulum, covered with green and pointed bracts. It is rich in polyphenols, flavonoids, anthocyanins, phenolic compounds, inulin, coumarins, terpenes, dietary fibre, enzymes, polysaccharides, minerals and vitamins, and therefore has a wide range of uses, including in the food industry, medicine and biofuels. Several studies have shown that artichokes have properties such as antioxidant, anti-inflammatory, antimicrobial, anticancer, hypocholesterolaemic, anti-HIV, cardioprotective, hepatoprotective and lipid-lowering effects. The aim of this study is to provide a literature review on the phytochemical composition, bioactivity and applications, focusing on the methods of extraction, purification and concentration of enzymes present in artichoke.

5.
J Food Sci Technol ; 60(4): 1323-1331, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36936119

RESUMEN

The objective of the present study was to develop tofu with soybean-water soluble extract coagulated with cardoon flower (F1) and magnesium chloride (MgCl2, F2). The produced tofu was characterized in terms of physical, chemical, microbiological, and sensory properties during 14 days of storage. The yield of F1 was higher (p < 0.05) (195 g/100 soybean seeds) than F2 (162 g/100 soybean seeds). F1 presented higher moisture, protein, acidity, syneresis, and lipids when compared with F2, and a reduction of these contents during the storage. F1 presented lower hardness, stickiness, springiness, and cohesiveness compared with F2. The acceptability of F1 showed a score of 6.00 and F2 of 4.68, and the purchase intention was 3.22 for F1 and 2.23 for F2. This study recommended the use of cardoon flower at 35% level as it has great potential as a coagulant for the elaboration of tofu with higher yield, and acceptability and reasonable purchasing intention.

6.
Food Sci Technol Int ; 29(4): 310-317, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35238680

RESUMEN

This study evaluated the influence of O2-absorbing sachets into different packages polyethylene terephthalate (PET - E1), low density polyethylene (LDPE - E2), and PET/LDPE (E3) on the quality of minimally processed soybean sprouts (MP-sprouts). The MP-sprouts were stored up to 12 days and characterized for physicochemical, microbiological and sensory attributes. The O2-absorbing sachet showed changes during exposure to the environment by the formation of amorphous iron hydroxide, which was observed by the analysis of functional groups and XRD. The packaging used in the study showed high transmittance and clarity, and low Haze, being a good feature for storing the MP product. All packaging systems showed an increase in the volume of absorbed oxygen (cm3) up to 9 days of storage. The physic-chemical characteristics of the MP-sprouts stored for 12 days were preserved in the different packages, showing no difference regarding the use of the O2-absorbing sachet. The O2-absorbing sachet not influenced the quality of MP-sprouts during the stored (12 days). The best visual aspect was observed in PET package (with and without O2-absorbing sachet) being classified as excellent, without color change. The MP-sprouts also fulfilled the microbiological quality standards and presented 75.11% acceptability and 72.40% purchase intention.


Asunto(s)
Embalaje de Alimentos , Conservación de Alimentos , Embalaje de Alimentos/métodos , Conservación de Alimentos/métodos , Glycine max , Polietileno , Oxígeno
7.
Food Res Int ; 161: 111851, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36192978

RESUMEN

Compounds that reduce or neutralize free radicals have been evaluated for use as nutraceutical or antioxidant additives in processed foods. This study aimed to enzymatically produce ascorbyl oleate and assess its biological properties. The synthesis was performed under previously maximized conditions (L-ascorbic acid/oleic acid 1:9 molar ratio, 70 °C, 1 h reaction). Immobilized commercial lipase from Candida antarctica (NS 88011) was used as biocatalyst. The reaction product was isolated, and its structure was confirmed by High-Performance Liquid Chromatography and Nuclear Magnetic Resonance. Ascorbyl oleate showed antioxidant and antimicrobial activity, besides no toxicity, did not influencing blood coagulation and also not presenting hemolytic profile. Better storage stability was achieved under refrigerated conditions, and the oxidative stability demonstrated free radicals fighting efficiency, increasing olive oil's shelf life. In vitro gastrointestinal simulation showed that ascorbyl oleate maintained antioxidant potential up to the duodenum stage during the digestive process. Therefore, the synthesized natural compound presented a high potential to be applied in the food and pharmaceutical industries.


Asunto(s)
Antiinfecciosos , Antioxidantes , Antiinfecciosos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Enzimas Inmovilizadas/química , Proteínas Fúngicas , Lipasa/química , Ácido Oléico , Ácidos Oléicos , Aceite de Oliva
8.
Meat Sci ; 194: 108966, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36126391

RESUMEN

The objective of this work was to develop, characterize and evaluate the application of active edible films based on gelatin and green tea extract in coating of fresh sausages. The green tea extract showed IC50 of 0.088 mg/mL and minimum inhibitory concentrations of 0.05 mg/mL for Listeria monocytogenes, 0.025 mg/mL for Staphylococcus aureus, 0.04 mg/mL for Escherichia coli, and >1.0 mg/mL for Salmonella enterica serovar Choleraesuis. The formulation with 15% (w/v) of gelatin and 30% (w/w) of glycerol showed better adhesion and appearance in the coating of the product. When using 1.0% of green tea extract, the lowest IC50, was obtained and the antioxidant activity was maintained for 35 days. There was a more accentuated decrease in pH and an increase in acidity and peroxide index in fresh sausages without film compared to those coated with the active film (1.0% of green tea extract) during storage. In addition, it was found that the use of active gelatin film (1.0% of green tea extract) kept the TBARS indexes of fresh sausage samples lower than the standard (without coating) and of films containing only gelatin, after 48 days of storage.


Asunto(s)
Antioxidantes , Películas Comestibles , Antioxidantes/farmacología , Gelatina/química , Extractos Vegetales/farmacología , Escherichia coli , Té/química
9.
Bioprocess Biosyst Eng ; 45(9): 1465-1476, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35876965

RESUMEN

The purpose of this study was the production of maltobionic acid, in the form of sodium maltobionate, by Z. mobilis cells immobilized in polyurethane. The in situ immobilized system (0.125-0.35 mm) was composed of 7 g polyol, 3.5 g isocyanate, 0.02 g silicone, and 7 g Z. mobilis cell, at the concentration of 210 g/L. The bioconversion of maltose to sodium maltobionate was performed with different cell concentrations (7.0-9.0 gimobilized/Lreaction_medium), temperature (30.54-47.46 °C), pH (5.55-7.25), and substrate concentration (0.7-1.3 mol/L). The stability of the immobilized system was evaluated for 24 h bioconversion cycles and storage of 6 months. The maximum concentration of sodium maltobionate was 648.61 mmol/L in 34.34 h process (8.5 gdry_cell/Lreaction_medium) at 39 °C and pH 6.30. The immobilized system showed stability for 19 successive operational cycles of 24 h bioconversion and 6 months of storage, at 4 °C or 22 °C.


Asunto(s)
Zymomonas , Células Inmovilizadas/metabolismo , Disacáridos , Fermentación , Poliuretanos , Sodio/metabolismo , Zymomonas/metabolismo
10.
Braz. arch. biol. technol ; 63: e20170710, 2020. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1132254

RESUMEN

Abstract (1) Background: The aim of this study was to evaluate the production and partial characterization of xylanase and avicelase by a newly isolated Penicillium sp. in solid-state fermentation, using soybean hulls as substrate. (2) Methods: Temperature, time, number of spores, and substrate moisture on xylanase and avicelase bioproduction were evaluated, maximizing activity with 30°C, 1x106 spores/g substrate, 14 and 7 days of fermentation with 70 and 76% substrate moisture contents, for xylanase and avicelase, respectively. (3) Results: Different solvents, temperatures, and agitation in the enzymatic extraction were evaluated, obtaining higher activities, 430.77 and 26.77 U/g for xylanase and avicelase using 30 min extraction and 0.05 M citrate buffer solution (pH 4.5 ), respectively at 60°C and 175 rpm and 50°C and 125 rpm. The optimum pH and temperature for enzymatic activity determination were 5.3 and 50°C. Enzyme extract stability was evaluated, obtaining higher stability with pH between 4.5 and 5.5, higher temperature of up to 40°C. The kinetic thermal denaturation (Kd), half-life time, D-value, and Z-value were similar for both enzymes. The xylanase Ed value (89.1 kJ/mol) was slightly lower than the avicelase one (96.7 kJ/mol), indicating higher thermostability for avicelase. (4) Conclusion: In this way, the production of cellulases using alternative substrates is a way to reduce production costs, since they represent about 10% of the world demand of enzymes, with application in animal feed processing, food production and breweries, textile processing, detergent and laundry production, pulp manufacturing and the production of biofuels.


Asunto(s)
Penicillium/aislamiento & purificación , Penicillium/enzimología , Glycine max/microbiología , Xilosidasas/biosíntesis , Celulasas/biosíntesis , Temperatura , Factores de Tiempo , Sustratos para Tratamiento Biológico
11.
Food Sci Biotechnol ; 28(3): 931-937, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31093452

RESUMEN

ABSTRACT: The aim of this study was to evaluate the mycotoxicological quality of wheat flours used by bakeries from the North Region in Rio Grande do Sul state, Brazil, regarding the presence of mycotoxins. On collecting type-1 refined wheat flour, a conglomerate sampling from 13 cities and 3 bakeries per city (n = 39), selected from the defined region was performed. The mycotoxins analysis was using QuEChERS method and UPLC-MS/MS analysis. As a result, 100% of samples presented contamination by DON, with concentrations ranging from 76.7 to 3630.2 µg kg-1 and ZON was found in one sample (26.7 µg kg-1), which represented 2.6% of the analyzed wheat flours. Other mycotoxins (AFB1, AFB2, AFG1, AFG2, DAS, HT-2 toxin, OTA, FB1 and FB2) were not detected in the analyzed samples.

12.
Poult Sci ; 97(12): 4462-4469, 2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30101324

RESUMEN

This study aimed to evaluate the parameters that influence the water absorption and drip of chicken carcasses due to the processing and pre-cooling of the meat in an industrial chiller. A total of 1,179 chickens were sampled during industrial processing to evaluate the influence of variables, validate the parameters, and conduct histological analysis. The best parameters for guaranteeing absorption levels and drip tests within acceptable limits on chicken carcasses were total residence time of 60 min (in the pre-chiller, chiller 1, and chiller 2); air pressure of chillers at 0.5 bar; the abdominal opening of carcasses at a maximum of 2 cm. These parameters did not influence the protein content, moisture/protein ratio, pH, or lipid content. The validation of the parameters and the histological analysis performed after each cooling stage showed that the most significant structural changes occurred in the pre-chiller, where the temperature of carcasses and water was higher, which contributes to greater absorption.


Asunto(s)
Frío , Manipulación de Alimentos , Carne/análisis , Músculos Pectorales/fisiología , Agua/análisis , Adsorción , Animales , Pollos
13.
Food Sci Technol Int ; 24(2): 97-109, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28956454

RESUMEN

This study aims at investigating pectin lyase bioproduction in submerged fermentation with synthetic medium and agro-industrial residues, using the filamentous fungus Aspergillus brasiliensis. The maximum pectin lyase activity in a synthetic medium (42 g/l pectin, 40 g/l yeast extract, and 0.02 g/l iron sulfate) was 31 U/ml, and 46 U/ml in the agro-industrial medium (160 g/l orange peel, 150 g/l corn steep liquor, and 300 g/l parboiled rice water), obtained over 60 and 124 h of bioproduction, 180 r/min, 30 ℃, pHinitial 5.5, and 5·106 spores/ml, respectively. Partial characterization of pectin lyase crude enzyme extract obtained from the synthetic medium and the one made of agro-industrial residues showed optimum conditions at pH of 5.5 and 4.5 and temperatures of 37 and 55 ℃, respectively. The Ed obtained was 3.13 and 9.15 kJ/mol, and the half-life time (t1/2) was 5.71 and 80 h at 55 ℃ for pectin lyase produced in synthetic and agro-industrial medium, respectively.


Asunto(s)
Aspergillus/enzimología , Biotecnología/métodos , Proteínas Fúngicas/biosíntesis , Residuos Industriales/análisis , Polisacárido Liasas/biosíntesis , Agricultura/economía , Aspergillus/crecimiento & desarrollo , Aspergillus/metabolismo , Biotecnología/tendencias , Brasil , Citrus sinensis/química , Productos Agrícolas/química , Productos Agrícolas/economía , Estabilidad de Enzimas , Fermentación , Manipulación de Alimentos , Industria de Procesamiento de Alimentos/economía , Frutas/química , Frutas/economía , Proteínas Fúngicas/química , Proteínas Fúngicas/economía , Proteínas Fúngicas/genética , Calor , Concentración de Iones de Hidrógeno , Residuos Industriales/economía , Cinética , Oryza/química , Polisacárido Liasas/química , Polisacárido Liasas/economía , Polisacárido Liasas/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/economía , Proteínas Recombinantes/aislamiento & purificación , Zea mays/química
14.
Artículo en Inglés | MEDLINE | ID: mdl-28786343

RESUMEN

The study evaluated a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method for use with a TLC quantification procedure for deoxynivalenol (DON). It also surveyed DON occurrence in wheat flour from the southern region of Brazil. Forty-eight wheat flour samples were analysed, divided into 2 different harvest lots, each consisting of 24 different brands. The detection and quantification limits of the method were 30 and 100 ng of DON on the TLC plate. The various concentrations of DON presented high linearity (R2 = 0.99). A negative matrix effect (-28%) of the wheat flour was verified, with suppression of the chromatographic signal of DON, and 80.2-105.4% recovery. The TLC method was reliable for DON evaluation, with a coefficient of variation of less than 10%. High-performance liquid chromatography of lot 2 samples confirmed the presence of DON in all samples identified DON-positive by the TLC technique. Of the 48 wheat flour samples in lots 1 and 2 analysed by TLC, 33.3 and 45.8% of the samples respectively were above the Brazilian legislation limit. Correlations were observed between the water activity and DON content, and between the fungal count and moisture content of the wheat flours.


Asunto(s)
Harina/análisis , Contaminación de Alimentos/análisis , Tricotecenos/análisis , Triticum/química , Brasil , Cromatografía en Capa Delgada
15.
Bioprocess Biosyst Eng ; 38(12): 2497-502, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26341112

RESUMEN

The aim of this research was the partial characterization of polygalacturonase (PG) extracts produced by a newly isolated Penicillium brasilianum and Aspergillus niger in submerged fermentation. The partial characterization of the crude enzymatic extracts showed optimum activity at pH 5.5 and 37 °C for both extracts. The results of temperature stability showed that PG from both microorganisms were more stable at 55 °C. However, the enzyme obtained by P. brasilianum presents a half-life time (t 1/2 = 693.10 h), about one order of magnitude higher than those observed in for A. niger at 55 °C. In terms of pH stability, the PG produced by P. brasilianum presented higher stability at pH 4.0 and 5.0, while the PG from A. niger showed higher stability at pH 5.0.


Asunto(s)
Aspergillus niger/enzimología , Penicillium/enzimología , Poligalacturonasa/metabolismo , Estabilidad de Enzimas , Calor , Concentración de Iones de Hidrógeno , Temperatura
16.
Ciênc. rural ; 45(7): 1311-1318, 07/2015. tab, graf
Artículo en Portugués | LILACS | ID: lil-749781

RESUMEN

Com a intenção de minimizar a carência de produtos isentos de glúten e tendo em vista o crescente aumento de celíacos, a elaboração de produtos diferenciais a base de farinha de arroz e milho torna-se uma alternativa de consumo e comercialização. Assim, este trabalho teve como objetivo avaliar os efeitos da adição de farinha de arroz e milho, e emulsificante nas características de qualidade (teste de cozimento, textura instrumental - firmeza e aceitabilidade) e físico-químicas (proteínas, lipídios, carboidratos, minerais e fibra alimentar) de formulações de macarrão, mediante o emprego de metodologia de planejamento de experimentos, fixando a concentração de ovos in natura (12%, m/m) e água (20%, v/m). A formulação com 40g de farinha de milho, 60g de farinha de arroz e 0,4g de SSL por 100g de farinha mista foi a que apresentou melhor resistência ao cozimento, menores perdas de sólidos na água de cocção (2,12% m/m), textura (30,40g seg-1) e aceitabilidade superior a 85 %. Além disso, o uso de farinha de arroz, associado à farinha de milho, proporciona fonte de minerais (152mg de K, 1,55mg de Fe, 46mg de Mg, 20mg de Ca por 100g), proteínas (~7%), carboidratos (52%) e fibras (~1%), importante suprimento nutricional para celíacos, por estes apresentarem perdas significativas destes nutrientes, devido à diarreia e à absorção restrita, característica da doença.


In order to minimize the deficiency of products with gluten-free and the growing number of celiac the elaboration of differential products using rice and maize flour becomes an alternative of consuming and marketing. This study aimed to evaluate the effects of rice and maize flour, and emulsifier addition in the quality characteristics (cooking test, instrumental texture - firmness and acceptability) and physic-chemical (proteins, lipids, carbohydrates, minerals and dietary fiber) of pasta formulation, by the use of experimental design methodology, fixing the concentration of in nature eggs (12%, w/w) and water (20%, v/w). The formulation with 40g of maize flour, 60g of rice flour and 0.4g per 100g of SSL mixed flour showed the better cooking resistance, reduced loss of solids in the cooking water (2.12% m/m), texture (30.40g sec-1) and acceptability higher than 85%. Furthermore, the use of rice flour associated with maize flour provide a source of minerals (152mg of K, 1.55mg of Fe, 46mg of Mg, 20mg Ca per 100g), proteins (~ 7%), carbohydrates (52%), fibers (~1%) important nutritional supplement for celiac, because they present significant losses of these nutrients due to restricted absortion and diarrhea, characteristic of the disease.

17.
Braz. arch. biol. technol ; 57(6): 908-915, Nov-Dec/2014. tab, graf
Artículo en Inglés | LILACS | ID: lil-730395

RESUMEN

Penicillium brasilianum was previously isolated from tea and identified by molecular biology technique. A Plackett-Burman design, followed by a complete second order design was used for the screening of most important factors and to maximize the pectin liase (PMGL) activity, respectively. The maximum PMGL activity by P. brasilianum achieved was 9.0 U/mL after 48 h of cultivation in a medium containing pectin (33.0 g/L), yeast extract (30.0 g/L) and potassium phosphate (2.0 g/L) at 30ºC, with a stirring rate of 180 rpm, initial pH 5.5 and 5x106 spores/mL inoculum size. The kinetic evaluation in terms of substrate consumption demonstrated that the maximum production of PMGL was at 72 h, and 40% of the total organic carbon, 25% of the nitrogen, 88% of the magnesium, 13% of the potassium and 66% of the iron were consumed. The pH remained almost stable during the whole period of production (5.33 to 4.9). The partial characterization of the crude PMGL enzyme extract showed optimal pH and temperature of 5.5 and 37°C, respectively.

18.
J Sci Food Agric ; 94(14): 2905-11, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24578290

RESUMEN

BACKGROUND: This study investigated the performance of a membrane reactor system for esterification of oleic acid and butyric acid with ethanol by Penicillium crustosum lipase using polyethersulfone membranes with molecular weight cut-offs of 30, 60 and 100 kDa at pressures up to 200 kPa. RESULTS: The confinement of lipase with 60 and 100 kDa membranes showed the best results. The esterification of butyric acid in the membrane reactor and with free lipase showed higher conversions than those obtained with oleic acid, since the system operated with oleic acid was more subject to fouling and thus could not be run for repeated cycles. CONCLUSION: The confinement of lipase from P. crustosum in a membrane reactor was possible, resulting in the satisfactory conversion of butyric acid to ethyl butyrate with the possibility of reuse of the immobilized enzyme.


Asunto(s)
Reactores Biológicos , Ácidos Grasos/metabolismo , Lipasa/metabolismo , Penicillium/enzimología , Ácido Butírico/química , Ácido Butírico/metabolismo , Enzimas Inmovilizadas , Etanol/química , Etanol/metabolismo , Fermentación , Membranas Artificiales , Ácido Oléico/química , Ácido Oléico/metabolismo , Factores de Tiempo
19.
Appl Biochem Biotechnol ; 163(3): 383-92, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20669053

RESUMEN

The aim of this work was to perform the screening of microorganisms, previously isolated from samples of agro-industrial waste and belonging to the culture collection of our laboratory, able to produce polygalacturonases (PG). A total of 107 microorganisms, 92 newly isolated and 15 pre-identified, were selected as potential producers of enzymes with PG activity. From these microorganisms, 20 strains were able to synthesize PG with activities above 3 U mL(-1). After the kinetic study, the enzyme activity was increased up to 13 times and the microorganism identified as Aspergillus niger ATCC 9642 and the newly isolated W23, W43, and D2 (Penicillium sp.) after 24 h of fermentation led to PG activities of 30, 41, 43, and 45 U mL(-1), respectively. The RAPD analysis demonstrated that the selected strains differs genetically, indicating that no duplication of strains among them in the experiments for polygalacturonases production was verified.


Asunto(s)
Hongos/enzimología , Poligalacturonasa/biosíntesis , Poligalacturonasa/metabolismo , Fermentación , Hongos/genética , Hongos/aislamiento & purificación , Concentración de Iones de Hidrógeno , Filogenia , Factores de Tiempo
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