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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.

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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.

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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.

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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.

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The objective of the present study was to evaluate the use of fermented and non-fermented whole rice bran for rotifer feeding, based on the effects on growth parameters, antioxidant and oxidative damage responses, and water quality. The study was based on three experiments, which compared the effect of different concentrations of non-fermented whole rice bran, the effect of different concentrations of fermented whole rice bran and the effect of the best concentrations of fermented and non-fermented whole rice bran, as well as the replacement of part of the baking yeast by rice bran. The results showed the best growth performances in treatments with 0.7 g yeast with 1.5 g fermented rice bran, 0.35 g yeast with 0.75 g whole rice bran, and 0.35 g yeast with 0.75 g fermented rice bran. Fermentation of rice bran for 6 hours did not induce oxidative stress in rotifers. This work revealed that the use of 1.5 g of fermented bran and replacement of 50% of yeast with fermented or non-fermented rice bran may be used for rotifer feeding, with the additional benefit of improving the environmental quality due to the lower amount of ammonia released in the water.

O objetivo do presente trabalho foi avaliar a utilização do farelo de arroz integral e fermentado na alimentação de rotíferos, baseado nos efeitos sobre os parâmetros de desempenho, respostas antioxidantes e de dano oxidativo, e qualidade de água. O estudo foi baseado em três experimentos, os quais compararam o efeito de diferentes concentrações de farelo de arroz integral na alimentação de rotíferos, o efeito de diferentes concentrações de farelo de arroz fermentado na alimentação de rotíferos e o efeito das melhores concentrações de farelo de arroz integral e fermentado, bem como a substituição de parte da levedura de panificação por esses farelos. Os resultados mostraram um melhor desempenho em crescimento nos tratamentos com 0,7 g de levedura, 1,5 g de farelo fermentado, 0,35 g de levedura + 0,75 g de farelo integral e 0,35 g de levedura +0,75 g de farelo fermentado. A fermentação do farelo de arroz por 6 horas não induziu estresse oxidativo nos rotíferos. Foi constatado que pode ser usado 1,5 g de farelo fermentado  e substituído 50% de levedura por farelo de arroz fermentado ou integral na alimentação de rotíferos, com a vantagem de apresentar melhor qualidade ambiental, devido a diminuição da amônia da água.

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The objective of the present study was to evaluate the use of fermented and non-fermented whole rice bran for rotifer feeding, based on the effects on growth parameters, antioxidant and oxidative damage responses, and water quality. The study was based on three experiments, which compared the effect of different concentrations of non-fermented whole rice bran, the effect of different concentrations of fermented whole rice bran and the effect of the best concentrations of fermented and non-fermented whole rice bran, as well as the replacement of part of the baking yeast by rice bran. The results showed the best growth performances in treatments with 0.7 g yeast with 1.5 g fermented rice bran, 0.35 g yeast with 0.75 g whole rice bran, and 0.35 g yeast with 0.75 g fermented rice bran. Fermentation of rice bran for 6 hours did not induce oxidative stress in rotifers. This work revealed that the use of 1.5 g of fermented bran and replacement of 50% of yeast with fermented or non-fermented rice bran may be used for rotifer feeding, with the additional benefit of improving the environmental quality due to the lower amount of ammonia released in the water.(AU)

O objetivo do presente trabalho foi avaliar a utilização do farelo de arroz integral e fermentado na alimentação de rotíferos, baseado nos efeitos sobre os parâmetros de desempenho, respostas antioxidantes e de dano oxidativo, e qualidade de água. O estudo foi baseado em três experimentos, os quais compararam o efeito de diferentes concentrações de farelo de arroz integral na alimentação de rotíferos, o efeito de diferentes concentrações de farelo de arroz fermentado na alimentação de rotíferos e o efeito das melhores concentrações de farelo de arroz integral e fermentado, bem como a substituição de parte da levedura de panificação por esses farelos. Os resultados mostraram um melhor desempenho em crescimento nos tratamentos com 0,7 g de levedura, 1,5 g de farelo fermentado, 0,35 g de levedura + 0,75 g de farelo integral e 0,35 g de levedura +0,75 g de farelo fermentado. A fermentação do farelo de arroz por 6 horas não induziu estresse oxidativo nos rotíferos. Foi constatado que pode ser usado 1,5 g de farelo fermentado  e substituído 50% de levedura por farelo de arroz fermentado ou integral na alimentação de rotíferos, com a vantagem de apresentar melhor qualidade ambiental, devido a diminuição da amônia da água.(AU)

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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.

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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.

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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.

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