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1.
Eur J Pharm Sci ; 197: 106766, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38615970

RESUMO

One of the most frequent causes of respiratory infections are viruses. Viruses reaching the airways can be absorbed by the human body through the respiratory mucosa and mainly infect lung cells. Several viral infections are not yet curable, such as coronavirus-2 (SARS-CoV-2). Furthermore, the side effect of synthetic antiviral drugs and reduced efficacy against resistant variants have reinforced the search for alternative and effective treatment options, such as plant-derived antiviral molecules. Curcumin (CUR) and quercetin (QUE) are two natural compounds that have been widely studied for their health benefits, such as antiviral and anti-inflammatory activity. However, poor oral bioavailability limits the clinical applications of these natural compounds. In this work, nanoemulsions (NE) co-encapsulating CUR and QUE designed for nasal administration were developed as promising prophylactic and therapeutic treatments for viral respiratory infections. The NEs were prepared by high-pressure homogenization combined with the phase inversion temperature technique and evaluated for their physical and chemical characteristics. In vitro assays were performed to evaluate the nanoemulsion retention into the porcine nasal mucosa. In addition, the CUR and QUE-loaded NE antiviral activity was tested against a murine ß-COV, namely MHV-3. The results evidenced that CUR and QUE loaded NE had a particle size of 400 nm and retention in the porcine nasal mucosa. The antiviral activity of the NEs showed a percentage of inhibition of around 99 %, indicating that the developed NEs has interesting properties as a therapeutic and prophylactic treatment against viral respiratory infections.


Assuntos
Administração Intranasal , Antivirais , Curcumina , Emulsões , Quercetina , Curcumina/administração & dosagem , Curcumina/farmacologia , Curcumina/química , Quercetina/administração & dosagem , Quercetina/farmacologia , Quercetina/química , Animais , Antivirais/administração & dosagem , Antivirais/farmacologia , Antivirais/química , Camundongos , Nanopartículas/administração & dosagem , Nanopartículas/química , Suínos , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/virologia , Infecções Respiratórias/prevenção & controle , Mucosa Nasal/metabolismo , Mucosa Nasal/efeitos dos fármacos , Mucosa Nasal/virologia , SARS-CoV-2/efeitos dos fármacos , Tratamento Farmacológico da COVID-19 , Humanos
2.
Animals (Basel) ; 13(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37835652

RESUMO

Peroxidase (PO) has been applied in different areas of industrial biotechnology, including the control of contaminants like aflatoxin B1 in fish feeds. However, its potential negative interactions with the macro and micro components of feeds have not been evaluated. The aim of this study was to evaluate the impact of PO's addition to a feed on compounds like fatty acids and polyphenols using an in vitro simulation of the digestive tract of the tilapia. The influence on fatty acids was determined by changes in the peroxide index, with the feed including PO presenting values four times higher than those of the control feed. On the other hand, the in vitro digestive simulation also evidenced an effect of PO on the bioaccessibility of polyphenols significantly influenced by the total digestion time and temperature. The bioaccessibility of polyphenol ranged from 2.09 to 16.23 µmol of the total Trolox equivalent antioxidant capacity for the combinations evaluated in the study. The greatest bioaccessibility was observed at the central point under the following conditions of digestive hydrolysis: pH of 7, 30 °C, 4.5 h of digestive hydrolysis and an absence of PO.

3.
Toxins (Basel) ; 15(9)2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37755988

RESUMO

Mycotoxins are a major source of contamination in cereals, posing risks to human health and causing significant economic losses to the industry. A comprehensive strategy for the analysis of 21 mycotoxins in Italian cereal grain samples (n = 200) was developed using a simple and quick sample preparation method combined with ultra-high-performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry (UHPLC Q-Orbitrap HRMS). The proposed method showed some advantages, such as multi-mycotoxin analyses with simple sample preparation, fast determination, and high sensitivity. The analysis of the sample revealed the presence of 11 mycotoxins, with α-zearalenol being the most frequently detected, while deoxynivalenol exhibited the highest contamination level. Furthermore, co-occurrence was identified in 15.5% of the samples under analysis. Among these, 13% of the samples reported the simultaneous presence of two mycotoxins, while 2.5% showed the co-occurrence of three mycotoxins. Currently, there has been a renewed interest in guaranteeing the quality and safety of products intended for human consumption. This study holds significant value due to its ability to simultaneously detect multiple mycotoxins within a complex matrix. Furthermore, it provides findings regarding the occurrence and co-occurrence of emerging mycotoxins that currently lack regulation under the existing European Commission Regulation.


Assuntos
Contaminação de Medicamentos , Micotoxinas , Humanos , Cromatografia Líquida de Alta Pressão , Grão Comestível , Espectrometria de Massas
4.
Artigo em Inglês | MEDLINE | ID: mdl-36395353

RESUMO

Potential of the enzyme peroxidase (PO) from soybean meal to mitigate aflatoxin B1 (AFB1) in fish feed was evaluated. Reaction parameters studied in the wet stage of the feed production process were enzyme activity (0.01-0.1 U/g), temperature (20-36 °C), time (0-8 h) and humidity content (40-70%). Feed was produced in conformity with the National Research Council and spiked with AFB1 at 10 ng/g. Any residual concentration of AFB1 in the diet was extracted by the QuEChERS method and quantified by a liquid chromatograph with a fluorescence detector. AFB1 mitigation of 90% was reached when feed production conditions were 0.035 U/g, 32 °C, 6 h and 70% humidity. Therefore, application of PO to the feed industry may be considered a promising tool for mitigation of AFB1, considering its toxicity and frequent occurrence. In addition, it guarantees safe food for consumers of fish farming products, as AFB1 can bioaccumulate in the food chain. It also provides an alternative use for soybean meal that would previously be discarded.


Assuntos
Aflatoxina B1 , Peroxidase , Animais , Aflatoxina B1/análise , Farinha , Ração Animal/análise , Peroxidases , Peixes , Glycine max
5.
Braz J Microbiol ; 53(4): 1881-1891, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36199005

RESUMO

Glutathione (GSH) and peroxidase (POD) are biomolecules of interest in the global market; thus, it is desirable to seek ways to increase their production. Magnetic field (MF) application is one of the technologies used in cultivation that has shown promising results to increase bioproducts. Therefore, this study aimed at evaluating the influence of MFs on GSH and POD production by Saccharomyces cerevisiae ATCC 7754. Different periods of MF application (35 mT) were evaluated over 72 h. The highest GSH production was reached in 48 h of cultivation in assays MF 0-24 (155.32 ± 9.12 mg L-1) and MF 0-72 (149.27 ± 3.62 mg L-1), which showed an increase of 121.9 % and 113 %, respectively, by comparison with the control without any MF application. The highest POD activity was achieved when MFs were applied throughout the culture (36.31 U mg-1) and POD productivity of 0.72 U mg-1 h-1. MF application throughout cultivation proved to be a promising strategy since all responses increased, i.e., GSH concentration, GSH productivity, POD activity, and POD productivity increased 113.7 %, 113 %, 20.4 %, and 28.6 %, respectively. This study is one of the first to consider MFs as a viable and low-cost alternative to produce GSH and POD in bioprocesses.


Assuntos
Peroxidase , Saccharomyces cerevisiae , Glutationa , Peroxidases , Oxirredutases , Campos Magnéticos , Antioxidantes
6.
Food Res Int ; 157: 111317, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35761607

RESUMO

The relation between contamination by trichothecenes, DON (Deoxyvalenol) and 15-ADON (15-acetil-deoxyvalenol), and enzymes, protease, ß-amylase and α-amylase, in the mashing step was studied. Malted barley was subject to mashing at three temperature ramps, which resulted in enzyme extracts. Enzyme activity of the extract was evaluated in a model solution with DON and 15-ADON. Results indicated that activities of protease and ß-amylase are changed by trichothecenes. Reduction in 15-ADON concentration was 100% when the initial concentration was 0.23 µg mL-1 and 74, 72 and 92% when it was 0.85 µg mL-1, under activities of protease, ß-amylase and α-amylase, respectively. On the other hand, DON concentration increased 45 and 30% under protease and ß-amylase activities, respectively. Malt contamination by DON and 15-ADON can affect enzyme activity and modify the process yield, which may cause economic losses.


Assuntos
Micotoxinas , Tricotecenos , beta-Amilase , Peptídeo Hidrolases , alfa-Amilases
7.
Food Chem ; 340: 127935, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32891895

RESUMO

This study aimed at evaluating mitigation of nivalenol (NIV) in alcoholic fermentation with magnetic field application (MF). Mitigation was related to both the glutathione (GSH) redox molecule and the enzyme peroxidase (PO), which were synthesized by Saccharomyces cerevisiae US-05. Conditions under evaluation were NIV (0.2 µg mL-1), MF application (35 mT) and simultaneous use of mycotoxin and MF. The GSH content and the PO activity were increased when the culture contained NIV and the alcohol profile was altered after 48 h of fermentation. At the end of the alcoholic fermentation, NIV was mitigated by 56.5%. Therefore, this process is a promising method to reduce contamination by NIV, although the mycotoxin affects the chemical characteristics of the final product.


Assuntos
Bebidas Alcoólicas , Microbiologia de Alimentos/métodos , Tricotecenos/metabolismo , Etanol/análise , Fermentação , Glutationa/metabolismo , Campos Magnéticos , Micotoxinas/química , Peroxidases/metabolismo , Saccharomyces cerevisiae/metabolismo
8.
Food Addit Contam Part B Surveill ; 13(4): 244-251, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32643592

RESUMO

In this study Aflatoxin B1 (AFB1), ochratoxin A (OTA) and zearalenone (ZEN) occurrence in fish feed, regarding its chemical composition, were investigated. Besides, AFB1 bioaccessibility to fish was evaluated by in vitro digestion. Mycotoxins were extracted by QuEChERS and quantified by HPLC-FLD. Results showed that 93.3% of the samples were contaminated at maximum levels of 16.5, 31.6, and 322 µg/kg in the cases of AFB1, OTA, and ZEN, respectively. A positive correlation between OTA, ZEN contamination, and lipid content was observed. Risk estimation of feed consumption by fish at the highest levels of AFB1, OTA, and ZEN shows that the younger the fish, the higher the risk of exposure to mycotoxins. The AFB1 bioaccessibility assay showed that 85% of this mycotoxin may be absorbed by fish. Therefore, establishing maximum levels in the fishing sector is fundamental to contribute to feed quality and nutritional safety of fish species.


Assuntos
Ração Animal/análise , Peixes/metabolismo , Micotoxinas/análise , Micotoxinas/farmacocinética , Aflatoxina B1/análise , Aflatoxina B1/farmacocinética , Ração Animal/microbiologia , Animais , Aquicultura , Carpas/metabolismo , Ciclídeos/metabolismo , Contaminação de Alimentos/análise , Ocratoxinas/análise , Ocratoxinas/farmacocinética , Zearalenona/análise , Zearalenona/farmacocinética
9.
Food Res Int ; 131: 109039, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32247492

RESUMO

The aim of this study was to evaluate the action of the commercial peroxidase (POD) enzyme (Armoracia rusticana) on the simultaneous degradation of ochratoxin A (OTA) and zearalenone (ZEA) in model solution and beer. For this purpose, the reaction parameters for POD action were optimized, POD application in the degradation of mycotoxins in model solution and beer was evaluated and the kinetic parameters of POD were defined (Michaelis-Menten constant - KM and maximal velocity - Vmax). In the reaction conditions (pH 7, ionic strength of 25 mM, incubation at 30 °C, addition of 26 mM H2O2 and 1 mM potassium ion), POD (0.6 U mL-1) presented the maximum activity for simultaneous degradation of OTA and ZEA of 27.0 and 64.9%, respectively, in model solution after 360 min. The application of POD in beer resulted in the simultaneous degradation of OTA and ZEA of 4.8 and 10.9%, respectively. The kinetic parameters KM and Vmax for degradation of OTA and ZEA were 50 and 10,710 nM and 0.168 and 72 nM min-1, respectively. Therefore, POD can be a promising alternative to mitigate the contamination of OTA and ZEA in model solution and beer, minimizing their effects in humans.


Assuntos
Cerveja/análise , Contaminação de Alimentos/análise , Ocratoxinas/análise , Peroxidases/metabolismo , Zearalenona/análise , Cerveja/microbiologia , Análise de Alimentos , Microbiologia de Alimentos , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Reprodutibilidade dos Testes
10.
Crit Rev Microbiol ; 46(1): 26-37, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32065532

RESUMO

With the productive intensification of fish farming, the partial or total replacement of fishmeal by ingredients of plant origin became a reality within the feed industry, with the aim of reducing costs. However, this practice increased the impact of mycotoxin contamination. Studies have shown that mycotoxins can induce various disorders in fish, such as cellular and organic alterations, as well as impair functional and morphological development, and, in more severe cases, mortality. Thus, studies have been conducted to evaluate and develop strategies to prevent the formation of mycotoxins, as well as to induce their elimination, inactivation or reduction of their availability in feed.


Assuntos
Ração Animal/microbiologia , Doenças dos Peixes/induzido quimicamente , Micotoxinas/análise , Micotoxinas/toxicidade , Animais , Doenças dos Peixes/prevenção & controle , Pesqueiros , Peixes , Contaminação de Alimentos/análise
11.
Bioprocess Biosyst Eng ; 43(2): 261-272, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31578604

RESUMO

Enzymes are becoming tools in industrial processes because of several advantages, including activity in mild environmental conditions, and high specificity. Peroxidase, for one, stably oxidizes several substrates. The present study aimed to develop advanced oxidation processes (AOP), using non-commercial rice bran peroxidase to remove color and toxicity of synthetic textile wastewater. Using a microwave and shaker system, we obtained 38.9% and 100% of effluent color removal after peroxidase treatment, respectively. In addition, the shaker system decants residual dye particles through filtration, providing the textile industry with an economical and environmentally viable alternative to effluent treatment. In toxicity tests results, both treatment systems damaged the used genetic material. This damage occurs because of industrial discharge of wastewater into water bodies; effluent dilution reduced this damage. The data suggest that peroxidase as a textile effluent treatment has potential uses in industrial processes, because rice bran peroxidase has demonstrated affinity with dyes.


Assuntos
Corantes/química , Oryza/enzimologia , Peroxidase/química , Proteínas de Plantas/química , Têxteis , Purificação da Água , Oxirredução , Indústria Têxtil , Águas Residuárias/química
12.
Artigo em Inglês | MEDLINE | ID: mdl-31599694

RESUMO

Ochratoxin A (OTA) is a secondary metabolite produced by filamentous fungi species belonging to the genera Penicillium and Aspergillus. The contamination of grapes by ochratoxigenic species occurs worldwide in regions of tropical and temperate climates. Better control of fungal growth is achieved through good cultural practice and proper selection of fungicides. Kresoxim-methyl and famoxadone are the most common fungicides used in vineyards. This study aimed at analysing the OTA production and toxigenic potential of Aspergillus carbonarius under fungicide treatment with famoxadone and kresoxim-methyl. The growth rate of A. carbonarius was evaluated by measuring the glucosamine content and the diameter of the fungal colonies. OTA production was quantified by HPLC analysis. The treatment with fungicides, kresoxim-methyl and famoxadone, significantly reduced the fungal growth, by 76% and 60%, respectively. However, the mycotoxin production was greater in the fungicide-treated groups than the control group, showing that even though the fungicides were effective in controlling fungal growth, they were ineffective against mycotoxin production.


Assuntos
Aspergillus/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Estrobilurinas/toxicidade , Aspergillus/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Fungicidas Industriais/análise , Estrobilurinas/análise
13.
Braz J Microbiol ; 50(4): 1075-1082, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31338707

RESUMO

This study aimed at evaluating the potential of the peroxidase (PO) enzyme to reduce ochratoxin A (OTA) levels and its application to grape juice. Both commercial PO and PO extracted from rice bran were evaluated, respectively, regarding their activity towards OTA in a model system. The affinity between PO and OTA was verified by the Michaelis-Menton constant and the maximum velocity parameters, resulting in 0.27 µM and 0.015 µM min-1 for the commercial enzyme, and 6.5 µM and 0.031 µM min-1 for PO extracted from rice bran, respectively. The lowest residual OTA levels occurred when 0.063 U mL-1 of the enzyme was applied. Under these conditions, the OTA reduction was 41% in 5 h for the commercial enzyme, and 59% in 24 h, for PO extracted from rice bran. When the extracted PO, with the activity of 0.063 U mL-1, was applied to whole grape juice, the OTA levels decreased to 17%, at 24 h. The capacity shown by PO for reducing OTA levels was confirmed in whole white grape juice, as a model system. This study may assist the wine industry to offer healthier products and add value to rice bran. Graphical abstract.


Assuntos
Sucos de Frutas e Vegetais/análise , Ocratoxinas/química , Oryza/enzimologia , Peroxidase/química , Proteínas de Plantas/química , Vitis/química , Biocatálise , Manipulação de Alimentos , Cinética
14.
Food Addit Contam Part B Surveill ; 12(2): 97-104, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30700225

RESUMO

Aflatoxin M1 (AFM1) and aflatoxin B1 (AFB1) were determined in 51 milk powder samples purchased from different grocery stores located in the Caribbean region of Colombia. Analysis was conducted using QuEChERS extraction and high-performance liquid chromatography with fluorescence detection. Results from the analytical method showed recovery ranges from 65% to 110% and relative standard deviations lower than 20%. AFM1 was detected in 100% of the milk samples (0.20-1.19 µg/kg) and 55% exceeded the maximum level in milk (0.5 µg/kg) set by the Colombian and European regulations. AFB1 was not detected in any of the analysed samples. Considering the measured contamination the maximum AFM1 level that can be ingested by consumption of milk powder is 0.007-0.013 µg/person/day. These values are above the average dietary intake estimated in Latin America according to the Joint FAO/WHO Expert Committee, which is 0.0035 µg/person/day.


Assuntos
Aflatoxina B1/análise , Aflatoxina M1/análise , Alimentos em Conserva/análise , Leite/química , Adulto , Animais , Criança , Colômbia , Europa (Continente) , Feminino , Contaminação de Alimentos/análise , Contaminação de Alimentos/legislação & jurisprudência , Humanos , Masculino , Concentração Máxima Permitida , Fatores de Risco
15.
Artigo em Inglês | MEDLINE | ID: mdl-29889651

RESUMO

The peroxidase (POD) enzyme, obtained from different sources, has been described in the literature regarding its good results of reduction in concentration or degradation levels of mycotoxins, such as aflatoxin B1, deoxynivalenol and zearalenone (ZEA). This study aimed at evaluating the action of commercial POD and POD from soybean bran (SB) and rice bran (RB) in ZEA reduction in a model solution and the characterisation of the mechanism of enzyme action. POD was extracted from SB and RB in phosphate buffer by orbital agitation. Evaluation of the action of commercial POD and POD from SB and RB in ZEA reduction was carried out in phosphate buffer and aqueous solution, respectively. Parameters of (Michaelis-Menten constant) (KM) and maximal rate (Vmax) were determined in the concentration range from 0.16 to 6 µg mL-1. ZEA reduction was determined and the mechanism of enzyme action was characterised by FTIR and high-pressure liquid chromatography-electrospray tandem mass spectrometry. Commercial POD and POD from RB and SB reduced ZEA concentration by 69.9%, 47.4% and 30.6% in 24 h, respectively. KM values were 39.61 and 8.90 µM, whereas Vmax values were 0.170 and 0.011 µM min-1 for commercial POD and POD from RB, respectively. The characterisation of the mechanism of enzyme action showed the oxidoreductive action of commercial POD in the mycotoxin. The use of commercial POD and POD from agro-industrial by-products, such as SB and RB, could be a promising alternative for ZEA biodegradation.


Assuntos
Contaminação de Alimentos/análise , Glycine max/enzimologia , Peroxidases/metabolismo , Zea mays/enzimologia , Zearalenona/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem , Zearalenona/metabolismo
16.
J Environ Sci Health B ; 52(10): 777-783, 2017 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-28937911

RESUMO

Deoxynivalenol (DON), one of the main mycotoxins found in food matrices, has high level of toxicity. This study aimed to characterize the peroxidase enzyme extracted from rice bran to be applied to the biodegradation of DON in order to evaluate the potential peroxidase (PO) from rice bran (RB) has to degrade DON in optimal conditions. Purification and recovery factors of PO extracted from RB and purified by three-phase partitioning were 5.7% and 50%, respectively. PO had the highest level of activity in the phosphate buffer 5 mM pH 5.5 in both crude and purified forms, whose reaction temperatures were 25°C and 10°C. At the end of production, purification and characterization steps, specific activities of the bran were 115.79 U mg-1 and 4363 U g-1. Reduction in the mycotoxin DON in optimal conditions determined for PO from RB was 20.3%, a promising result when the aim is to adequate mycotoxicological levels to foods.


Assuntos
Peroxidase/metabolismo , Tricotecenos/metabolismo , Estabilidade Enzimática , Contaminação de Alimentos , Concentração de Íons de Hidrogênio , Oryza/enzimologia , Peroxidase/isolamento & purificação , Temperatura
17.
World J Microbiol Biotechnol ; 33(9): 169, 2017 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-28831658

RESUMO

Static or modulated magnetic fields (MF) may interact with the biological system and affect the metabolism of microorganisms, such as their photosynthetic capacity or synthesis of carbohydrates. Their effects on microorganisms, which can be classified into inhibiting, stimulating and null, may be interpreted as the result of stress that cells undergo, thus, leading to responses through the same mechanisms. Biological effects of exposure to magnetic forces depend on magnetic intensity, frequency and exposure time. Modifications in these parameters may enhance product formation. Effects differ according to the form and application of MF characteristic parameters. Magnetic treatments have the advantages of being convenient and non-toxic, having low running cost, emitting no secondary pollution, enabling wide application and being easily shielded. MF application to the cultivation of microalgae, to improve the production of finished biomolecules, is a simple, inexpensive and powerful process. However, bioeffects of MF on microalgae need to be further investigated because there have currently been very few available reports in the literature. Thus, studies which aim at optimizing parameters involved in MF application must be developed in order to obtain the best conditions for the production of molecules with high economic potential.


Assuntos
Bioengenharia/métodos , Microalgas/crescimento & desenvolvimento , Metabolismo dos Carboidratos , Fenômenos Magnéticos , Microalgas/metabolismo , Fotossíntese
18.
Pestic Biochem Physiol ; 108: 21-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24485311

RESUMO

Fusarium graminearum is a fungal species complex pathogenic occurring worldwide, mainly associated with cereal crops. The most important Fusarium mycotoxins are fumonisins, zearalenone and trichothecenes. The availability of efficient control measures that are less harmful to both the environment and the consumers is urgent. For such, phenolic acids (PAs) from natural sources are known to reduce fungal contaminations. This work aimed to identify the PAs present in a culture extract of Spirulina algae (strain LEB-18) and evaluate its effect on mycelial growth rate, glucosamine level, amylase activity and mycotoxin production by four strains of two lineages of F. graminearum. Results showed that amendment of potato dextrose media with LEB-18 extract (3% w/v), which was mainly composed by gallic acid, greatly reduced radial growth of fungal colonies compared to media containing a single PA and the control. Also, average reductions of 40% and 62% in the glucosamine levels and the amylase activity were observed. In general, the LEB-18 extract and the PAs reduced mycotoxin concentration, with an average reduction of 68% for the trichothecene mycotoxins deoxynivalenol and nivalenol.


Assuntos
Antifúngicos/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Hidroxibenzoatos/farmacologia , Micotoxinas/biossíntese , Spirulina/química , Antifúngicos/química , Antifúngicos/isolamento & purificação , Regulação para Baixo/efeitos dos fármacos , Fusarium/metabolismo , Hidroxibenzoatos/química , Hidroxibenzoatos/isolamento & purificação , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Micélio/metabolismo
19.
Rev. Inst. Adolfo Lutz ; 70(2): 185-92, abr.-jun. 2011. tab, graf
Artigo em Português | LILACS, Sec. Est. Saúde SP, SESSP-CTDPROD, Sec. Est. Saúde SP, SESSP-ACVSES, SESSP-IALPROD, Sec. Est. Saúde SP, SESSP-IALACERVO | ID: lil-620806

RESUMO

Os cereais são fontes de inibidores enzimáticos que agem sobre a α-amilase, que alteram a disponibilidade do amido e podem representar uma ferramenta útil para a resistência dos vegetais ao ataque de agentes patogênicos. Neste estudo foram analisadas as características físico-químicas e da fração proteica de aveia, arroz e trigo, cultivados no Rio Grande do Sul, com o objetivo de correlacioná-las, posteriormente, com apresença de inibidores enzimáticos e resistência à contaminação fúngica. As amostras de grãos de aveia, trigo e arroz foram caracterizadas físico-quimicamente e avaliadas quanto à digestibilidade proteica in vitro, solubilidade em sistema aquoso e atividade enzimática de hidrolases. A aveia apresentou maior teor lipídico e proteico e a cultivar UPFA 20 Teixeirinha demonstrou a menor digestibilidade em função do teor de fibras. O maior conteúdo de glutelina foi detectado no arroz cultivar BR 424, acompanhado pelo maior teor de proteína bruta e digestibilidade. As variedades de trigo apresentaram maior atividade de α-amilase e β-amilase, o que sugere que esse cereal é mais susceptível à degradação fúngica quando comparado com arroz e aveia, em vista da maior disponibilidade de açúcares. A atividade inibidora de amilases dos extratos proteicos dos cereais foi maior nos cultivares de aveia.


Assuntos
Avena , Grão Comestível , Inibidores Enzimáticos , Oryza , Proteínas , Solubilidade , Triticum , alfa-Amilases
20.
Braz. arch. biol. technol ; 53(3): 505-511, May-June 2010. graf, tab
Artigo em Inglês | LILACS | ID: lil-548569

RESUMO

The objective of this work was to evaluate the effect of DON and T-2 toxin levels on the malt amylase activity. The malt was contaminated in accordance with central composite design experiment with DON and T-2 toxin levels until 1000 ng/g. The activities of the enzymes were evaluated by Bernfeld method. The increase in T-2 toxin concentration inhibited the α-amylase activity. However, the increase of both toxins concentration caused inverse effect. The interaction between toxins indicated synergetic effect on the β-amylase activity. An increased activity occurred when the toxins contamination levels in malt were higher (1000ng/g malt). The trichothecenes interfered with the performance of aminolitic enzymes in the stage of malting, resulting in a significant model for enzymatic activity of β-amylase.


O objetivo deste trabalho foi avaliar o efeito de deoxynivalenol e toxina T-2 na atividade de a e b-amilase em malte. A contaminação artificial foi de acordo com planejamento experimental completo nos níveis de 0 a 1000ng/g para cada micotoxina. O aumento da concentração da toxina T-2 inibiu a atividade da a-amilase. Entretanto, a coocorrência a altas concentrações das duas toxinas indicou efeito sinergistíco. Um aumento da atividade enzimática ocorreu na presença de altos níveis das micotoxinas avaliadas (1000ng/g de malte). Os tricotecenos interferiram na performance das enzimas aminolíticas na etapa de malteação, permitindo determinar um modelo preditivo para a atividade da β-amylase.

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