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1.
Food Chem ; 457: 140086, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38936121

RESUMO

Food intake contributes to adequate growth and neurodevelopment of children. Ready-to-eat foods, frequently consumed by this population, are sources of acrylamide (AA), hydroxymethylfurfural (HMF) and furfural (FF). In this sense, a review of the AA, HMF, and FF presence in ready-to-eat foods was evaluated through a systematic search to infer the risk of exposure in the child population. About 75.8%, 24.2%, and 21% of the studies found AA, HMF, and FF in ready-to-eat foods, respectively. AA is predominant in processed and ultra-processed foods, while HMF and FF are commonly found in fruit-based foods. Only 17.7% of the studies assessed the children's risk of exposure, based on the contaminant concentration in ready-to-eat food and not after gastrointestinal digestion, a more realistic measure. Therefore, with the obtained information and found gaps, it is expected that new strategies will be proposed to assess the vulnerability of the child population to these processing contaminants.

2.
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
3.
Foods ; 13(7)2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38611416

RESUMO

Among microorganisms found in food, fungi stand out because they are adaptable and competitive in a large range of water activities, temperatures, pHs, humidities and substrate types. Besides sporulating, some species are toxigenic and produce toxic metabolites, mycotoxins, under adverse biotic and abiotic variables. Microorganisms are inactivated along the food chain, but mycotoxins have stable structures and remain in ready-to-eat food. The most prevalent mycotoxins in food, which are aflatoxins, fumonisins, ochratoxin A, patulin, tenuazonic acid, trichothecenes and zearalenone, have maximum tolerable limits (MTLs) defined as ppb and ppt by official organizations. The chronic and acute toxicities of mycotoxins and their stability are different in a chemical family. This critical review aims to discuss promising scientific research that successfully mitigated levels of mycotoxins and focus the results of our research group on this issue. It highlights the application of natural antifungal compounds, combinations of management, processing parameters and emergent technologies, and their role in reducing the levels and bioaccessibility. Despite good crop management and processing practices, total decontamination is almost impossible. Experimental evidence has shown that exposure to mycotoxins may be mitigated. However, multidisciplinary efforts need to be made to improve the applicability of successful techniques in the food supply chain to avoid mycotoxins' impact on global food insecurity.

4.
Food Chem ; 405(Pt B): 134944, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36401893

RESUMO

This study evaluated sixteen Polycyclic Aromatic Hydrocarbons (PAHs) considered priority pollutants by the United States Environmental Protection Agency (USEPA) in 13 honey samples from seven Meliponinae species, collected in native forests and industrial areas in southern Brazil. All samples contained at least one PAH. ∑PAHs ranged from 1.4 to 23.3 µg kg-1, where 23 % of samples were above the maximum allowed levels in dietary food for special medical purposes. Furthermore, the Excess Cancer Risk (ECR) ranged from 1.67 × 10-5 to 6.17 × 10-3, and 2.97 × 10-6 to 1.10 × 10-3, according to the Brazilian Institute of Geography and Statistics (IBGE) and Food and Agriculture Organization (FAO) daily intakes, respectively, being 61.54 % and 15.38 % of the samples above the threshold classified into sever by the USEPA. Results highlighted that honey has been affected by PAH contamination and that it has the potential to be used as an indicator of environmental pollution.


Assuntos
Poluentes Ambientais , Mel , Hidrocarbonetos Policíclicos Aromáticos , Estados Unidos , Abelhas , Animais , Brasil , Poluição Ambiental
5.
Food Res Int ; 162(Pt B): 112085, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36461334

RESUMO

This study aimed to determine Patulin (PAT) in samples of organically and conventionally grown tomato varieties, to correlate it with their phenolic profile and at evaluating effects of phenolic extracts of tomato samples against the Penicillium expansum CCT 7549 strain. Four varieties of tomatoes (Cherry, Khaki, Italian and Long Life) subject to conventional and organic management were collected in markets in the south of Brazil. PAT was determined in samples by validated method Matrix Solid Phase Dispersion (MSPD) with detection in HPLC-PDA. Titratable acidity, phenolic profile and antifungal activity (minimum inhibitory concentration - MIC and minimum fungicidal concentration - MFC) against P. expansum were determined. In most tomatoes PAT was found at levels that were below the Maximum Recommended Level (MRL = 50 µg/kg). Samples of conventionally grown Cherry tomato showed high acidity and PAT contamination, whose correlation was confirmed by the Principal Component Analysis (PCA). Phenolic extracts of tomatoes subject to conventional management were more efficient to inhibit P. expansum, a fact that may be explained by the content of caffeic acid. However, since PAT production was not inhibited in fruit, it is recommended that PAT should be monitored and a new management strategy should be investigated.


Assuntos
Patulina , Penicillium , Solanum lycopersicum , Fenóis/farmacologia
6.
J Food Sci Technol ; 59(8): 3192-3200, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35872723

RESUMO

One of the limitations of the use of corn in the food chain is its contamination with mycotoxins. Reduction in their levels can be achieved by processing the grain, which in the case of corn can be achieved by wet or dry milling. The aim of this study was to compare the distribution of aflatoxins B1 and B2, and fumonisin B1 in corn fractions obtained by dry and wet milling, aiming to identify conditions to mitigate the risk of exposure to these contaminants. Naturally, contaminated corn kernels were subjected to laboratory milling. The wet-milling conditions containing 1% lactic acid in the steeping solution and 18 h of steeping were the most efficient for mycotoxin reduction in the endosperm fraction, reducing aflatoxins B1 and B2 contamination to levels below the limit of quantification. Dry-milling reduced the concentration of these mycotoxins in the endosperm (98-99%). Fumonisin B1 contamination increased in the germ and pericarp fraction by more than three times in both dry and wet milling. Dry-milling reduced fumonisin B1 contamination in the endosperm to levels below the limit of quantitation. Wet and dry milling processes can be an efficient control method to reduce aflatoxins and fumonisin in the corn endosperm fraction. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05373-9.

7.
Artigo em Inglês | MEDLINE | ID: mdl-35652893

RESUMO

Tetradenia riparia is known for its richness in essential oil which has been widely investigated due to its biological activities such as antimicrobial, insecticidal, trypanocidal, antimalarial and antioxidant. The objective of this work was to chemically analyze and evaluate the antifungal and antimycotoxigenic activity of the essential oil and the crude extract of leaves, flower buds and stems of T. riparia from the northwest region of the state of Paraná. The essential oil was obtained by hydrodistillation using a Clevenger-type apparatus. To obtain the crude extract, the leaves, flower buds and stems were pulverized and subjected to a dynamic maceration process using 70% v v-1 ethyl alcohol. Chemical analysis of the essential oil was performed by GC/MS, and chemical identification of the crude extract by UHPLC-ESI/qTOF. Antifungal activity (Rhizopus oryzae, Aspergillus flavus, Aspergillus ochraceus, Penicillium verrucosum and Fusarium graminearum) was performed by broth microdilution and the antimycotoxigenic assay was performed with A. ochraceus and P. verrucosum. Ochratoxin A was extracted by partition with chloroform and quantified by HPLC-FL. The oil yield was 0.29% for leaves, 0.34% for stems and 0.38% for flower buds, and the major compounds were fenchone, ß-caryophyllene, α-cadinol, 14-hydroxy-9- epi-caryophyllene, 9ß,13ß-epoxy-7-abietene, α-cadinol and 6-7-dehydroroyleanone. The main chemical compounds identified in the crude extract were terpenes, anthocyanins, flavonoids, tannins and phenolic acids. The minimum inhibitory concentration (MIC) of oils from leaves, flower buds and stems for the strains tested ranged from 0.87 mg mL-1 to 33.3 mg mL-1, while the minimum fungicidal concentration (MFC) ranged from 6.94 mg mL-1 and 33.3 mg mL-1. The MIC and MFC for ketoconazole, tebuconazole, sorbate and nitrite ranged from 0.05 to 33.3 mg mL-1. The oil and crude extract of leaves, stems and flower buds showed an inhibition of ochratoxin A production for P. verrucosum of approximately 100%.


Assuntos
Lamiaceae , Óleos Voláteis , Antocianinas/análise , Antifúngicos/análise , Antifúngicos/farmacologia , Lamiaceae/química , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Extratos Vegetais/química , Folhas de Planta/química
8.
Food Chem ; 363: 130175, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34118754

RESUMO

This study evaluated the physicochemical parameters and the occurrence of pesticides in multi-flower honey produced by six species of Meliponinae and Apis mellifera and collected in different seasons, floral species and sites in southern Brazil. Meliponinae honey were found to exhibit higher moisture, free acidity and sucrose concentration and lower concentration of reducing sugars than the standard of Apis mellifera honey in Brazil. Regarding Apis mellifera honey, reducing sugars and sucrose did not comply with the legislation. The Principal Component Analysis (PCA) showed that most of the composition variability was defined by free acidity, moisture, soluble solids, fructose, glucose, and reducing sugars. Determination of pesticides was carried out by the citrate QuEChERS method and gas chromatography tandem mass spectrometry (GC-MS/MS). However, no pesticide residues at concentrations above the limit of quantification were found in the twenty honey samples. Results show that this region has the potential to produce honey.


Assuntos
Mel , Praguicidas , Animais , Abelhas , Brasil , Cromatografia Gasosa-Espectrometria de Massas , Mel/análise , Espectrometria de Massas em Tandem
9.
Mycotoxin Res ; 37(2): 161-168, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33751407

RESUMO

Fumonisins are a group of mycotoxins commonly associated with corn-based products and require innovative alternatives to control exposure to its toxicity. The objective of this research was to determine the effect of amylose and resistant starch on fumonisin B1 (FB1) levels in extruded corn-based products as well as the toxin bioaccessibility upon digestion. Cornmeal contaminated with FB1 (1.5 µg/g) was extruded alone or combined with high-amylose corn starch (20%, w/w). FB1 was quantified both in the unextruded and extruded products by HPLC (high-performance liquid chromatography) fluorescence detector with pre-column derivatization. Samples were then subjected to an in vitro digestion model to evaluate the stability of the interaction between FB1 and the corn matrix extruded. The addition of high-amylose corn starch further reduced the detection of FB1 (74.9%), when compared with the effect of the extrusion alone (66.0%), confirming the binding of FB1 with the macromolecules or resistant starch. The bound fumonisin was stable upon simulated gastric digestion, and the duodenal bioaccessibility of free FB1 was lower than 35% when high-amylose corn starch ingredient was used in the product. Principal component analysis (PCA) showed that high-amylose corn starch and resistant starch content influenced the reduction of FB1 and its duodenal bioaccessibility. This study for the first time shows that addition of high-amylose corn starch during extrusion is an innovative strategy to reduce FB1 release under digestive conditions, therefore useful in mitigating the exposure to this mycotoxin.


Assuntos
Fumonisinas/análise , Amido/química , Zea mays/química , Amilose/química , Bioacumulação , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Micotoxinas/análise
10.
Crit Rev Food Sci Nutr ; 61(2): 275-282, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32073888

RESUMO

Contamination of food by fungi can result in changes in sensory characteristics, as well as rapid reduction in quality and consequently the infeasibility of using contaminated material. In addition, contamination can pose a danger to public health, as in addition to decreasing the availability of nutrients, some fungal species can produce toxic substances. Much research has explored the use of natural resources to prevent or mitigate microbial contamination. Recovery of chemicals from many families from plants and microorganisms has been evaluated. Phenolic compounds are the most studied class on the premise that they have the capacity to inhibit endogenous and exogenous biological degradation processes. In this manuscript, we intend to emphasize the biochemical and experimental evidence of the phenolic compounds present in natural resources from the South of Brazil that have potential to be used in strategies to mitigate the consequences of fungal contamination. The crude phenolic extracts from natural resources (plant portion and microorganisms) of the Southern Brazilian region should be better exploited, to propose strategies to scale up their application in food industries because they have demonstrated an ability to inhibit fungal development without promoting stress and consequent mycotoxin production.


Assuntos
Fungos , Micotoxinas , Brasil , Humanos , Micotoxinas/análise , Recursos Naturais , Plantas
11.
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
12.
Food Chem ; 293: 112-119, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151590

RESUMO

A fast and simple method, which employs QuEChERS and HPLC-UV, was developed to determine preservatives in processed foods from different classes. The method showed correlation coefficients above 0.99, LOQs between 0.13 and 0.33 mg kg-1 and recoveries between 91 and 107%, with RSD ≤ 5.3%. Levels of preservatives were up to 2040 mg kg-1 for benzoates, up to 3185 mg kg-1 for sorbates and up to 452 mg kg-1 for methylparaben. Only four out of 82 samples under analysis were above the maximum level allowed by the legislation. Additionally, daily intakes of preservatives were estimated. Regarding benzoates, relatively high intakes were estimated (25% of the acceptable daily intake - ADI) in comparison with sorbates (5% of ADI) and parabens (<1% of ADI), when mean consumption is considered. This method is a good alternative to determining preservatives in different food samples.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Conservantes de Alimentos/análise , Benzoatos/análise , Cromatografia Líquida de Alta Pressão/normas , Análise de Alimentos , Limite de Detecção , Nível de Efeito Adverso não Observado , Parabenos/análise , Controle de Qualidade , Ácido Sórbico/análise , Espectrofotometria Ultravioleta , Inquéritos e Questionários
13.
Food Chem ; 283: 39-45, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30722888

RESUMO

The influence of particle size and chemical composition of three different cornmeals on the resistant starch (RS) content formed during the hydrothermal treatment was studied. The changes in reducing sugars and phenolic acids in different fractions caused by the hydrothermal treatment were correlated with RS content. The cornmeal with smaller particle size had higher RS content (202 mg/g). The hydrothermal treatment promoted a reduction in the total reducing sugars (46.7-84.5%), availability of free phenolic acids (256.7%) and reduction of the bound phenolic acids (71.1%). The correlation between RS contents and phenolic acids was determined by multivariate statistics and principal component analysis (PCA) showed that hydroxybenzoic and ferulic acids influence the formation of RS similar to type 5, amylose-phenol complex. The texture profile parameters (TPA) of cornmeal were negatively correlated with RS and differential scanning calorimetry (DSC) analysis showed consistency with this behavior.


Assuntos
Amido/química , Zea mays/química , Amilose/química , Varredura Diferencial de Calorimetria , Ácidos Cumáricos/química , Farinha/análise , Hidroxibenzoatos/química , Tamanho da Partícula , Análise de Componente Principal
14.
Environ Sci Pollut Res Int ; 26(5): 5131-5139, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30607853

RESUMO

This study proposed the optimization of a laccase-mediator system to reduce pesticide levels (bentazone, carbofuran, diuron, clomazone, tebuconazole, and pyraclostrobin) on aqueous medium. Firstly, the mediator concentration of 1 mM was established (average removal of 36%). After that, seven redox-mediating compounds, namely, 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, caffeic acid, chlorogenic acid, p-coumaric acid, ferulic acid, gallic acid, protocatechuic acid, and vanillin, were compared regarding their removal efficiency. The highest removal (77%) was achieved with the laccase-vanillin system. After this screening, the optimization was carried out by a 22 full factorial design. Variables under study were the enzyme (laccase) activity and vanillin concentration. Maximum removal (53-85%) was achieved with 0.95 U/mL laccase and 1.8 mM vanillin. Pesticide removal in reaction media was fitted to the first-order kinetics equation with an average half-time life of 2.2 h. This is the first study of the use of this natural compound as a mediator in the degradation of the pesticides under investigation. The results of this study contribute, with alternative methods, to decrease pesticide levels since they are highly persistent in aqueous samples and, as a result, mitigate the environmental impact.


Assuntos
Benzaldeídos/química , Lacase/metabolismo , Praguicidas/análise , Poluentes Químicos da Água/análise , Benzaldeídos/metabolismo , Biodegradação Ambiental , Catálise , Cinética , Oxirredução , Praguicidas/metabolismo , Trametes/enzimologia , Poluentes Químicos da Água/metabolismo
15.
Food Chem ; 214: 293-299, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27507478

RESUMO

Phenolic compounds, their inhibitory activity against fungal amylase and the occurrence of aflatoxins were determined in edible beans. The free, conjugated and bounded phenolic compounds and their phenolic acid profiles were determined in ten bean varieties. A method for aflatoxin B1, B2, G1 and G2 determination and confirmation by LC-MS/MS was validated. The red and carioca beans presented the highest total phenolic content (1.8 and 1.2mg.g(-1), respectively); the fradinho and white beans the lowest (0.18 and 0.19mg.g(-1), respectively). In the free and conjugated forms, chlorogenic acid was present in 60% of the samples, while in the bounded phenolic, ferulic acid was in 90% of the samples. The phenolic extracts were able to inhibit fungal amylase, and the PCA analysis confirmed that the relation between the chlorogenic and gallic acids is important to this effect. The absence of aflatoxins in samples confirm the protector effects of these phenolic compounds.


Assuntos
Aflatoxinas/análise , Fabaceae/química , Micotoxinas/análise , Fenóis/análise , Aflatoxina B1/análise , Ácido Clorogênico/análise , Cromatografia Líquida , Espectrometria de Massas em Tandem
16.
Toxicology ; 368-369: 91-102, 2016 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-27597255

RESUMO

Ochratoxin A (OTA) is a mycotoxin produced by several species of fungi from the Aspergillus and Penicillium genera that frequently grow in improperly stored food products. OTA has carcinogenic, teratogenic and nephrotoxic potential and sustains a high half-life in human blood. Despite the recently efforts to decontaminate OTA through its conversion into its metabolite ochratoxin alpha (OTα), there are just a few reports in literature comparing the toxic effects of these toxins. Thus, herein we studied and compared the proinflammatory and toxicological effects of OTA and its metabolite OTα in human neutrophils in vitro. The effect of OTA and OTα on human neutrophils viability was evaluated by trypan blue, annexin-V and propidium iodide methods as well as by the analysis of cytomorphological alterations. The ATP levels were also evaluated using the luciferin-luciferase bioluminescence assay. The alteration on mitochondrial potential was assessed by a mitoscreen flow cytometry mitochondrial membrane potential detection kit and the intracellular calcium levels through the probe FLUO-4/AM. To study the human neutrophils' oxidative burst, the fluorescent probe dichlorodihydrofluorescein diacetate was used. OTA induced an increase on the intracellular calcium, human neutrophils' oxidative burst followed by depletion of ATP levels and alterations on mitochondrial potential leading to cell death by necrosis, while OTα did not induce significant toxic effects. Our results strongly suggest that the toxicity in human neutrophils induced by OTA started with the release of calcium from internal stores triggering several neutrophils' activities that culminate in cell death by necrosis.


Assuntos
Necrose/patologia , Neutrófilos/efeitos dos fármacos , Ocratoxinas/química , Ocratoxinas/toxicidade , Carcinógenos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Contaminação de Alimentos , Microbiologia de Alimentos , Humanos , Potencial da Membrana Mitocondrial , Necrose/induzido quimicamente , Neutrófilos/citologia , Teratogênicos/toxicidade
17.
Appl Biochem Biotechnol ; 172(1): 458-68, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24092451

RESUMO

A multienzymatic complex production was evaluated, as well as endoglucanase and total cellulase characterization, during solid-state fermentation of rice industry wastes with Rhizopus oryzae CCT 7560 (newly isolated microorganism) and Trichoderma reesei QM 9414 (control). R. oryzae produced enzymes with higher activity at 15 h of fermentation (5.1 and 2.3 U g(-1) to endoglucanase and total cellulase), while T. reesei produced them at 55 h (15.3 and 2.8 U g(-1) to endoglucanase and total cellulase). The optimum temperature for total cellulase and endoglucanase was 60 °C. For Trichoderma and Rhizopus, the optimum pH was 5.0 and 6.0 for total cellulase and 6.0 and 5.0 for endoglucanase, respectively. The enzymes produced by Rhizopus presented higher stability at the temperature range evaluated (25-100 °C); the endoglucanase KM value was 20 times lower than the one found for Trichoderma. The characterization of the cellulolytic enzymes from the fungal species native of rice husk revealed that they can be more efficient than the genetically modified enzymes when rice husk and rice bran are used as substrates.


Assuntos
Celulase/biossíntese , Celulase/metabolismo , Rhizopus/metabolismo , Temperatura , Trichoderma/metabolismo , Celulase/química , Estabilidade Enzimática , Fermentação , Engenharia Genética , Concentração de Íons de Hidrogênio , Hidrólise , Resíduos Industriais , Cinética , Rhizopus/isolamento & purificação , Especificidade por Substrato , Termodinâmica , Trichoderma/genética , Trichoderma/isolamento & purificação
18.
Braz. arch. biol. technol ; 55(6): 937-942, Nov.-Dec. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-660343

RESUMO

The objective of this work was to evaluate the solid-state fermentation with Rhizopus oryzae CCT 7560 of rice bran for the enrichment of proteins and the antioxidant compounds in the fermented biomass. Fermentation was performed in tray bioreactors at 30ºC for 120 h. Protein extraction was done at alkaline pH, followed by precipitation with acetone. Phenolic compounds were extracted with cold methanol. The maximum protein was recovered from after 120 h (26.6%). The content of total phenolic compounds increased during the fermentation and was maximum after 96 h, which inhibited the DPPH radical by 87%. The promising characteristics of the protein and phenolic extracts of the biomass suggested the application in the coating composition for vegetal tissues preservation.

19.
Bioresour Technol ; 102(17): 8335-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21715163

RESUMO

The aim of this study was to evaluate fermented rice bran phospholipids, lipids and fatty acid content in a fermentation solid system with Rhizopus oryzae fungus. For this, aliquots were withdrawn every 24h over 120 h. The content of phospholipids was determined by colorimetric method. Esterified fatty acids were separated by gas chromatography, then identified and quantified. The total lipids from fermented rice bran (FB) decreased from 20.4% to 11.2% in the range between 0 h and 120 h of fermentation while phospholipid contents were increased up to 2.4 mg P g(lipid)(-1). In fermented bran, oleic, palmitic and linoleic acids prevailed, with a decrease in saturated fatty acids (20%) and increase in the unsaturated ones (5%). This study showed that rice bran fermentation with R. oryzae can be applied to the production of phospholipids altering the saturated to unsaturated fatty acid ratio.


Assuntos
Ácidos Graxos/metabolismo , Fermentação , Metabolismo dos Lipídeos , Oryza/metabolismo , Fosfolipídeos/metabolismo , Oryza/microbiologia
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