Mitigation of Mycotoxins in Food-Is It Possible?

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.

Effect of Gliding Arc Plasma Jet on the Mycobiota and Deoxynivalenol Levels in Naturally Contaminated Barley Grains.

Fusarium graminearum and Fusarium meridionale are primary contaminants of barley, capable of producing several mycotoxins, mainly type B trichothecenes and zearalenone. Cold plasma decontamination has been gaining prominence, seeking to control the fungal and mycotoxin contamination of food and feed and to improve product quality. To reach this objective, the present study was divided into two parts. In the first part, F. meridionale and F. graminearum strains were exposed to gliding arc plasma jet (GAPJ). Cell viability tests showed the inactivation of F. meridionale after 15-min treatment, whereas F. graminearum showed to be resistant. In the second part, barley grains were treated by GAPJ for 10, 20, and 30 min, demonstrating a reduction of about 2 log CFU/g of the barley's mycobiota, composed of yeasts, strains belonging to the F. graminearum species complex, Alternaria, and Aspergillus. A decrease in DON levels (up to 89%) was observed after exposure for 20 min. However, an increase in the toxin Deoxynivalenol-3-glucoside (D3G) was observed in barley grains, indicating a conversion of DON to D3G.

Rice Bran and Its Potential To Complement the Nutritional Needs of Children and Elderly.

Rice bran is an agro-industrial by-product of low added value that can be used to complement human nutritional needs. In this work, the profile of minerals, fatty acids and amino acids in brown rice bran was determined, aiming to evaluate its potential to complement the nutritional needs of different age groups, according to recommendations of regulatory agencies. The brown rice bran was supplied by a rice processing industry located in the south of the state of Rio Grande do Sul. Minerals were quantified using an emission spectrometer; the fatty acid profile was determined by gas chromatography and the amino acids were quantified by high-performance liquid chromatography with fluorescence (HPLC-FL). The main minerals were phosphorus (P), magnesium (Mg), potassium (K) and calcium (Ca) (2,933, 1,029, 211 and 56 mg / 100 g of rice bran). Saturated, monounsaturated and polyunsaturated fatty acids in rice bran were 22.4, 36.2 and 34.5% of lipid content, respectively. The polar, neutral and charged amino acids represented 8.8, 9.3 and 12.8% of the protein content, respectively. The composition of this co-product of rice supply chain is a good alternative to the new demand on plant-based food supplying the recommended daily intake (RDI) of national and international food polices.

Patulin in tomatoes and the inhibitory capacity of their phenolic extracts against Penicillium expansum.

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.

Ochratoxin A reduction by peroxidase in a model system and grape juice.

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.

Particle size and physical-chemical characteristics of hydrothermally treated cornmeal on resistant starch content.

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.

Evaluation of the TLC quantification method and occurrence of deoxynivalenol in wheat flour of southern Brazil.

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.

Phenolic compound in beans as protection against mycotoxins.

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.

Ochratoxin A activates neutrophils and kills these cells through necrosis, an effect eliminated through its conversion into ochratoxin α.

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.

Endoglucanase and total cellulase from newly isolated Rhizopus oryzae and Trichoderma reesei: production, characterization, and thermal stability.

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.

Effect of particle size and ammonium sulfate concentration on rice bran fermentation with the fungus Rhizopus oryzae.

The effects of rice bran particle size (0.18-0.39mm) and ammonium sulfate concentration in the nutrient solution (2-8g/L) on biomass production, protein and phenolic content generated by solid state fermentation with the fungus Rhizopus oryzae (CCT 1217) were studied. Particle size had a positive effect on biomass production and a negative effect (p⩽0.05) on protein and phenolic contents. Ammonium sulfate concentration had a positive effect (p⩽0.05) on biomass and phenolic content gain. Cultivation of fungus in rice bran with particle size of 0.18mm and in the presence of 8g/L ammonium sulfate, resulted in protein levels of 20g/100g dry wt and phenolics content of 4mg/g dry wt. These values were 53 and 65% higher than those achieved with unfermented rice bran. The results demonstrate that the fermentation process increased the value of compounds recovered for potential use in food formulations.

Evaluation of the composition of culture medium for yeast biomass production using raw glycerol from biodiesel synthesis

The work herewith investigated the production of yeast biomass as a source of protein, using Yarrowia lipolytica NRRL YB-423 and raw glycerol from biodiesel synthesis as the main carbon source. A significant influence of glycerol concentration, initial pH and yeast extract concentration on biomass and protein content was observed according to the 2v5-1 fractional design. These factors were further evaluated using a central composite design and response surface methodology, and an empirical model for protein content was established and validated. The biomass of Yarrowia lipolytica NRRL YB-423 reached 19.5 ± 1.0 g/L in shaken flasks cultivation, with a protein content of 20.1 ± 0.6% (w/w).

Evaluation of the composition of culture medium for yeast biomass production using raw glycerol from biodiesel synthesis.

The work herewith investigated the production of yeast biomass as a source of protein, using Yarrowia lipolytica NRRL YB-423 and raw glycerol from biodiesel synthesis as the main carbon source. A significant influence of glycerol concentration, initial pH and yeast extract concentration on biomass and protein content was observed according to the 2v (5-1) fractional design. These factors were further evaluated using a central composite design and response surface methodology, and an empirical model for protein content was established and validated. The biomass of Yarrowia lipolytica NRRL YB-423 reached 19.5 ± 1.0 g/L in shaken flasks cultivation, with a protein content of 20.1 ± 0.6% (w/w).

Compostos fenólicos totais, atividade antioxidante e antifúngica de multimisturas enriquecidas com a microalga Spirulina platensis / Total phenolic compounds, antioxidant and antifungal activities of multimixtures enriched by adding microalgae Spirulina platensis

Com o objetivo de avaliar o conteúdo fenólico e as atividades antioxidantes e antifúngicas de multimisturas enriquecidas com Spirulina platensis, foram formuladas quatro multimisturas com farelo de arroz ou trigo, duas contendo Spirulina platensis e duas com sementes de girassol. Os compostos fenólicos foram estimados pela técnica de Folin-Ciocalteau. A atividade antioxidante foi avaliada por meio de inibição do radical livre DPPH e a atividade antifúngica foi analisada por meio de ensaio de inibição do halo de crescimento de Aspergillusorizae. O conteúdo de compostos fenólicos totais e a atividade antioxidante nas multimisturas contendo farelo de arroz foram em média 0,6 vezes superiores aos encontrados nas multimisturas contendo farelo de trigo. As multimisturas formuladas com 1% da microalga não apresentaram diferença significativa (α=0,05) quanto ao conteúdo fenólico, quando comparadas às multimisturas padrão. A multimistura contendo farelo de arroz e Spirulina platensis apresentou maior atividade antioxidante, em comparação à multimistura padrão com o mesmo farelo, ao contrário do observado nas multimisturas contendo farelo de trigo, o que indica que a associação do farelo de arroz com a microalga é mais eficiente do que a formulação com farelo de trigo quanto à proteção contra processos oxidantes. Quanto à atividade antifúngica, as multimisturas com farelo de trigo apresentaram 28% de inibição, comparado a 21% das multimisturas contendo farelo de arroz.

Effects of aqueous extract from Stephanolepis hispidus on blood pressure in the normal and in L-NAME-induced hypertensive rats

O objetivo deste estudo foi o de investigar o efeito antihipertensivo do extrato aquoso da pele do peixe Stephanolepis hispidus (AqeSh) em ratos normotensos e hipertensos induzidos pelo tratamento com NG-nitro-L-arginina metil ester (L-NAME). O tratamento dos animais de experimentação com L-NAME (60 mg/l, água de beber) provocou um aumento sustentado na pressão arterial. O tratamento com AqeSh restaurou a pressão sanguínea para os níveis normais nos animais hipertensos. Além disso, o AqeSh preveniu o aumento da pressão sanguínea induzida pelo L-NAME. Ao final dos tratamentos não foram observadas diferenças significativas nos pesos corporal e dos órgãos vitais entre o grupo controle e os tratados. A avaliação hematológica e bioquímica não revelou diferenças entre os grupos exceto para os valores de AST e ALT no grupo hipertenso, provavelmente devido à presença do tratamento com L-NAME. Estes resultados sugerem que a administração oral do AqeSh previne o aumento da pressão sanguínea induzida pelo L-NAME. Este efeito pode ser mediado parcialmente por nitrito e nitrato presentes na pele do peixe.

Antioxidant properties of Spirulina (Arthospira) platensis cultivated under different temperatures and nitrogen regimes

The main aim of this work was to investigate the effects of temperature and nitrogen concentration on the antioxidant potential of extracts from Spirulina (Arthospira) platensis biomass. S. platensis biomass obtained at 35°C and with 1.875 g.L-1 or 2.5 g.L-1 of sodium nitrate in the culture medium presented higher concentrations of phenolic compounds. The antioxidant potential of methanol extracts of biomass on the enzymatic browning caused by peroxidase were 29 and 35 percent, respectively, being the reduction related to the amount of phenolic compounds present in this extract.

A cianobactéria Spirulina tem sido comercializada e estudada devido as suas propriedades nutricionais e terapêuticas no tratamento de doenças como o câncer, a hipercolesterolemia e a aterosclerose. Determinados compostos presentes na Spirulina, como os compostos fenólicos, a ficocianina e o tocoferol, podem apresentar atividade antioxidante. O principal objetivo deste trabalho foi avaliar o efeito da temperatura de cultivo e da concentração de nitrogênio no meio de cultivo, sobre o potencial antioxidante da microalga Spirulina (Arthospira) platensis. Quando a microalga foi cultivada a 35°C e concentrações de nitrato de sódio de 1,875 g.L-1 ou 2,5 g.L-1, o potencial antioxidante dos extratos obtidos a partir da biomassa, sobre o escurecimento enzimático causado pela peroxidase, foi de 29 por cento e 35 por cento, respectivamente, sendo a redução no escurecimento relacionada com as quantidades de compostos fenólicos presentes nos extratos.

Antinociceptive effects of the aqueous extract of Brugmansia suaveolens flowers in mice.

The infusion of Brugmansia suaveolens, popularly known as trombeteira or cartucheira, has been used to treat pain in Brazil. The present study was conducted to test for its antinociceptive effects using the abdominal-writhing, formalin, tail-flick, and hot-plate tests in mice. The aqueous extract from B. suaveolens flowers administered intraperitoneally at doses of 100 and 300 mg/kg body weight significantly inhibited acetic acid-induced abdominal constrictions. An increase in hot-plate latency was also observed in animals receiving both doses (100 and 300 mg/kg). In the formalin test, both doses from the aqueous extract inhibited the first (0-5 min) and second phase (20-25 min). Tail-flick assays demonstrated that treatment of animals with plant extract induced attenuation of the response. These results suggest that the aqueous extract from B. suaveolens flowers produced antinociceptive effects, as demonstrated in the experimental models of nociception in mice. This supports popular medicinal uses of this plant as an analgesic.

Caracterização química de pescados empregados para tratamento de asma brônquica na Região Sul do Rio Grande do Sul / Chemical characterization of fish species employed to Asthma treatment southern region of Rio Grande do Sul

Visando agregar conhecimento científico á cultura popular e disponibilizar informações sobre pescados disponíveis no litoral sul do Rio Grande do Sul, o presente trabalho teve por objetivo caracterizar quimicamente duas espécies de pescado, Balistes capriscus (peixe-porco) e Meticirrhus littoralis (papa-terra), aos quais a população da região Sul do Rio Grande do Sul atribui propriedades farmacológicas. Os pescados foram coletados junto à empresas e no entreposto pesqueiro da cidade do Rio Grande, RS. Para a caracterização físico-química foram separadas a porção comestível (músculo) e a pele das duas espécies. A composição química foi determinada por métodos da AOAC International (2000), exceto os lipídios que foram quantificados de acordo com método de Bligh e Dyer (1959). Os fosfolipídios foram determinados na fração lipídica por espectrofotometria segundo metodologia padrão alemã descrita por Esteves, Gonçalves e Barrera-Arellano (1995) adaptada para lipídios de pescado. O músculo e pele do peixe-porco e papa-terra apresentaram, respectivamente, média de 78,5 e 71,5; 80 e 75,5 de umidade; 1,4 e 11; 1,2 e 0,8 de cinzas; 18,8 e 16,7; 17,6 e 18,5 de proteína; 0,77 e 0,5; 0,82 e 7 de lipídios. Os valores de fosfolipídios obtidos foram de 17,2 mg.g-1 de LT (lipídios totais) e 11,3 mg.g-1 de LT para músculo e pele do peixe porco; 5,8 mg.g-1LT e 2,04 mg.g-1 de LT para músculo e pele do papa-terra. As relações de fosfolipídios/gordura nos músculos das duas espécies se mostraram semelhantes as mencionados para outros pescados citados na literatura. No entanto, na pele de peixe porco o teor de fosfolipídio é aproximadamente 5 vezes maior que na pele de papa-terra

Intenting to add scientic knowledge to popular culture and about fish species available in South Coastof Rio Grande do Sul, the objective of this paper was chemical characterization of two fishes species,Balistes capriscus (peixe-porco) and Meticirrhus littoralis (papa-terra) that the local population believesin its pharmacologic properties to asthma treatment. The fishes were collected in industries and in thepublic market of the city. The edible part(muscle) were separated from the skin, so characterized. Thechemical composition was determined by methods AOAC International (2000), except the lipids thatwere quantified by method Bligh and Dyer (1959). The phospholipids were determined in the lipidsfraction by spectrophotometry in according to German standard methodology described by Esteves,Gonçalves e Barrera-Arellano (1995) adapted to fish lipids. The muscle and skin of thepeixe porco andpapa-terrapresented, respectively, average of 78,5 and 71,5; 80 and 75.5% of humidity; 1,4 and 11; 1,2and 0.8% of ash; 18,8 and 16,7; 17,6 and 18.5% of protein; 0,77 and 0,5; 0,82 and 7% of lipids. Thephospholipids values obtained were 17,2 mg. g-1 of LT (total lipids) and 11,3 mg.g-1 of TL for muscle andskin of the peixe porco and 5,8 mg. g-1 TL and 2,04 mg. g-1 of TL for muscle and skin of the papa-terra. Therelations of phospholipids/total lipids in the muscle and skin from the two species were like the othersmarine species cited by the literature . However in the skin of peixe-porco the level of phospolipids isupper five that in skin of papa-terra

Vascular responses to extractable fractions of Ilex paraguariensis in rats fed standard and high-cholesterol diets.

The authors investigated the vasorelaxant properties of the aqueous (Aq-EF) and acid n-butanolic (acn-BuOH) extractable fractions from Ilex paraguariensis leaves. Perfusion pressure was evaluated using isolated and perfused mesenteric arterial beds (MABs) from rats fed hypercholesterolemic and standard diets. Extract-induced vasorelaxation in the presence and absence of various inhibitors was examined following precontraction of the MABs with methoxamine (30 microM) solution. In hypercholesterolemic-diet rats, relaxation in intact MABs was significantly decreased with ac-n-BuOH-EF bolus (300, 600, 900 microg) in comparison to those in standard-diet rats. After the endothelium was stripped from the MABs, the vascular responses to ac-n-BuOH-EF and 900 microg bolus of Aq-EF were significantly changed. Treatment of the MABs with an inhibitor of nitric oxide synthase, N(G)-nitro-L-arginine methylester hydrochloride (L-NAME, 10 mM), did not change either ac-n-BuOH-EF- or Aq-EF-induced vasodilation except for the 900 microg bolus of Aq-EF. The guanilate cyclase inhibitor methylene blue (100 microM) did not affect vasodilation for either fraction in the MABs from the hypercholesterolemic-diet rats. The chronic oral administration of I. paraguariensis extract in hypercholesterolemic-diet rats resulted in a significant reduction in serum levels of cholesterol and triglycerides. These results suggest that I. paraguariensis ac-n-BuOH-EF and Aq-EF induce vasodilation in standard-diet rats in a dose-dependent manner and that the hypercholesterolemic diet substantially reduced the effect of ac-n-BuOH-EF on precontracted MABs.