Prediction of fumonisins B1 and B2 in corn distiller's dried grains with solubles through near-infrared reflectance spectroscopy.

BACKGROUND: Distiller's dried grains with solubles (DDGS) are coproducts of the biofuel industries that use corn as raw material. This cereal is commonly contaminated by mycotoxins, including fumonisins (FBs), which can pose a serious health threat to humans and animals. Corn DDGS are typically used as a protein-rich animal feed. As mycotoxins from the original cereal grains become concentrated in DDGS, mycotoxicological monitoring is highly required before their use as ingredient in the industry. RESULTS: This work aimed to develop a methodology for predicting fumonisins B1 (FB1 ) and B2 (FB2 ) in corn DDGS using near-infrared reflectance spectroscopy (NIRS) technology associated with chemometric methods. One hundred and ninety corn DDGS samples originating from Brazilian ethanol plants and feed mills were included in this assessment. Two datasets were created: one for calibration (132 samples) and another for external validation (58 samples). Partial least squares regression and a cross-validation approach were applied to build the models. Liquid chromatography coupled to tandem mass spectrometry was used as the reference methodology. Calibration results of correlation coefficient and residual prediction deviation for FB1 and FB2 were, respectively, 0.90 and 0.88; and 2.16 and 2.06. CONCLUSION: Values of the external validation dataset were compared and no statistical difference was found between groups, indicating a satisfactory predictive ability and confirming the potential of NIRS to predict fumonisins in corn DDGS. © 2022 Society of Chemical Industry.

Near-infrared spectroscopy as a tool for rapid screening of deoxynivalenol in wheat flour and its applicability in the industry.

This study aimed to evaluate the applicability and efficiency of Near-Infrared Spectroscopy (NIR) by using dispersive NIR and Fourier Transform NIR to analyse 267 samples of Brazilian wheat flour contaminated with deoxynivalenol (DON). For this, Partial Least-squares Discriminant Analysis (PLS-DA) and Principal Component Analysis-Linear Discriminant Analysis (PC-LDA) were used as discriminatory methods. Next, the samples were classified according to the maximum tolerated limits (MTL) for DON in Brazil, 750 µg kg-1, and two groups were established for the calibration set: category A (≤450 µg kg-1), non-contaminated or below the MTL; and category B (>450 µg kg-1), contaminated or above the MTL. Validation samples through PLS-DA showed correct classification rates in the range of 85-87.5% and presented a 10-15% error; for PC-LDA, the hit rate was over 85% with an error of 10-15%. The present findings demonstrate that NIR is an excellent alternative method to classify wheat flour samples according to DON content.

Acute Silver Catfish (Rhamdia quelen) Exposure to Chlorantraniliprole Insecticide.

The aim of the current study is to investigate whether silver catfish (Rhamdia quelen) individuals exposed to commercial formulation of the chlorantraniliprole insecticide used in rice crops present changes in biochemical parameters. Fifty-four (54) silver catfish individuals were distributed in six units per tank (n = 6/repetition; triplicate/treatment) and subjected to the following treatments: T1-control, without insecticide; T2 (0.02 µg/L of insecticide) and T3 (0.20 µg/L of insecticide). Exposure time lasted 24 or 96 h, and it was followed by 96 h recovery in pesticide-free water. Results have indicated biochemical changes in cortisol, glucose, lactate and plasma protein levels, as well as few ionic changes in animals' gills during the exposure and recovery periods. Chlorantraniliprole incidence in water resulted in some biochemical changes in silver catfish specimens' plasma and gills throughout the acute exposure protocol (sub-lethal dose). Thus, chlorantraniliprole insecticide has caused osmoregulatory and/or biochemical imbalance in the investigated species under the herein adopted laboratory conditions; these changes did not get back to normal levels even after specimens were left to recover for 96 h in clean water.

Impact of deoxynivalenol on intestinal explants of broiler chickens: An ex vivo model to assess antimycotoxins additives.

The impact of deoxynivalenol (DON) upon intestinal tissue of broilers was assessed by using jejunal explants in Ussing chambers and analyzing histopathological and immunohistochemical parameters; this system was also applied to evaluate the efficacy of an antimycotoxins additive (AMA). The explants were subjected to the following treatments within each experiment for 120 min: Experiment 1) T1 (control) - buffer solution, and T2 - 10 mg/L DON; and Experiment 2) T1 (control) - buffer solution, T2 - 10 mg/L DON, T3 - AMA (0.5%), and T4 - 10 mg/L DON + 0.5% AMA. In Experiment 1, DON triggered a reduction in the size of enterocytes as well as of their nuclei, an increase in cytoplasmic vacuolization and apical denudation of villi. Apoptotic cells count was also greater in DON-exposed explants. In Experiment 2, the AMA mitigated DON harmful effects; cytoplasmic vacuolization of enterocytes was reduced and the size of their nuclei was preserved. The additive also promoted a partial decrease in microvillus integrity, in size of enterocytes and in apoptotic cells count. The tested ex vivo model demonstrated the impact of DON upon the intestine as well as the efficacy of the AMA against its damaging effects.

Multivariate method for prediction of fumonisins B1 and B2 and zearalenone in Brazilian maize using Near Infrared Spectroscopy (NIR).

Fumonisins (FBs) and zearalenone (ZEN) are mycotoxins which occur naturally in grains and cereals, especially maize, causing negative effects on animals and humans. Along with the need for constant monitoring, there is a growing demand for rapid, non-destructive methods. Among these, Near Infrared Spectroscopy (NIR) has made great headway for being an easy-to-use technology. NIR was applied in the present research to quantify the contamination level of total FBs, i.e., fumonisin B1+fumonisin B2 (FB1+FB2), and ZEN in Brazilian maize. From a total of six hundred and seventy-six samples, 236 were analyzed for FBs and 440 for ZEN. Three regression models were defined: one with 18 principal components (PCs) for FB1, one with 10 PCs for FB2, and one with 7 PCs for ZEN. Partial least square regression algorithm with full cross-validation was applied as internal validation. External validation was performed with 200 unknown samples (100 for FBs and 100 for ZEN). Correlation coefficient (R), determination coefficient (R2), root mean square error of prediction (RMSEP), standard error of prediction (SEP) and residual prediction deviation (RPD) for FBs and ZEN were, respectively: 0.809 and 0.991; 0.899 and 0.984; 659 and 69.4; 682 and 69.8; and 3.33 and 2.71. No significant difference was observed between predicted values using NIR and reference values obtained by Liquid Chromatography Coupled to Tandem Mass Spectrometry (LC-MS/MS), thus indicating the suitability of NIR to rapidly analyze a large numbers of maize samples for FBs and ZEN contamination. The external validation confirmed a fair potential of the model in predicting FB1+FB2 and ZEN concentration. This is the first study providing scientific knowledge on the determination of FBs and ZEN in Brazilian maize samples using NIR, which is confirmed as a reliable alternative methodology for the analysis of such toxins.

Toxicological response of silver catfish (Rhamdia quelen) after acute exposure to a commercial insecticide containing thiamethoxam.

This study assessed the hematological, enzymatic and osmoregulatory responses of silver catfish (Rhamdia quelen) exposed to sublethal concentrations (1.125 and 3.750 µg/L) of a commercial thiamethoxam-containing insecticide used on rice crops. Groups of 6 fish per tank (in triplicate, n = 3, total 54 fish) were exposed for up to 96 h to different concentrations of the compound. After this period, fish were placed in clean water for 48 h. Two fish from each tank (6 per treatment) that had been exposed to the insecticide for 24 h were anesthetized with eugenol and blood was collected to evaluate hematological and biochemical parameters. Blood, liver and muscle were collected for determination of metabolic parameters, plasma cortisol, Cl-, Na+ and K+ levels and H+-ATPase and Na+/K+-ATPase activity in the gill. H+-ATPase activity was higher in fish exposed to 1.125 µg/L insecticide at 24 h compared to control (0.0 µg/L). Differences in cortisol levels were evidenced throughout the experimental period. These results indicated that exposure to the insecticide changed the hematological, biochemical and metabolic profile of the animals, suggesting concern about environmental safety. Therefore, we discourage the use of this pesticide in areas that come into contact with water bodies inhabited by fish.

Growth of silver catfish ( Rhamdia quelen ) exposed to acidic pH at different humic acid levels / Crescimento de jundiás (Rhamdia quelen) expostos ao pH ácido em diferentes níveis de ácido húmico

ABSTRACT: Humic substances are organic compounds that possess high molecular weight and are formed by the decomposition of plant materials. Humic substances comprise humic acids, fulvic acids and humin. Humic acids (HA) have shown to be able to provide some protection to biological membranes of fish in water with low pH, replacing the protective action of Ca2+. Thus, this studyaimed to observe growth of silver catfish ( Rhamdia quelen ) juveniles exposed to pHs 5.5 and 6.5 and to different levels of HA: 0, 10, 25 and 50mg L-1. Results showed that, irrespective of pH, HA was highly detrimental to silver catfish growth, since the higher the concentration of HA, the lower the weight gain and feed intake, resulting in lower biomass and lower specific growth rate of juveniles. Hence, HA is extremely damaging to the performance of silver catfish juveniles in the tested concentrations.

RESUMO: Substâncias húmicas são compostos orgânicos que possuem elevado peso molecular e são formadas pela decomposição da matéria orgânica de plantas. As substâncias húmicas compreendem ácidos húmicos, ácidos fúlvicos e humina. Os ácidos húmicos (AH) têm mostrado serem capazes de proporcionar proteção parcial das membranas biológicas de peixes em águas com baixo pH, substituindo a ação protetora do Ca2+. Assim, este estudo teve como objetivo observar o crescimento de juvenis de jundiá ( Rhamdia quelen ) expostos a pH's 5,5 e 6,5 com diferentes níveis de AH: 0, 10, 25 e 50mg L-1. Os resultados demostram que, independentemente do pH, o AH foi altamente prejudicial para o crescimento do jundiá, uma vez que, quanto maior era a concentração de AH, menor era o ganho de peso e a ingestão de alimentos, resultando em menor biomassa e taxa de crescimento específico inferior dos juvenis. Assim, os AH são extremamente prejudiciais para o desempenho de juvenis de jundiá nas concentrações testadas.

Imazapyr+imazapic herbicide determines acute toxicity in silver catfish Rhamdia quelen.

Imazapyr (IMY) and imazapic (IMI) are imidazolinone herbicides which have been associated in a commercial formulation (Kifix(®)). To date, there are no studies on the toxicity of an IMY+IMI herbicide in fish. This work aimed to assess the acute toxicity (24 and 96 h) of IMY+IMI (0, 0.488 and 4.88 µg/L) towards Rhamdia quelen through hematological, biochemical, immunological, ionoregulatory and enzymatic indexes. Red blood cell count was lower at 4.88 than at 0.488 µg/L (24 and 96 h); mean corpuscular volume was lower than control at both concentrations (24 h) and at 0.488 µg/L (96 h); lymphocytes declined at 4.88 µg/L comparing to control (96 h); and monocytes increased at 4.88 µg/L (96 h) in comparison with the respective control and with 4.88 µg/L at 24h. Aspartate aminotransferase was higher at 0.488 µg/L (96 h) than the respective control and the respective concentration at 24 h; uric acid reduced at 4.88 µg/L comparing with 0.488 µg/L (96 h); and cortisol was lower at 4.88 µg/L compared to 0.488 µg/L and control (96 h). Herbicide exposure lowered plasma bactericidal activity at both concentrations (24 h) and at 0.488 µg/L (96 h); and plasma complement activity declined at 4.88 µg/L comparing with 0.488 µg/L and control (96 h), and was lower at all concentrations at 96 h than at 24 h. Plasma K(+) levels were higher at 4.88µg/L than in the remaining groups (24 and 96h); and Na(+) levels decreased at 4.88 µg/L compared to control (96 h). Na(+)/K(+)-ATPase and H(+)-ATPase activities in gills were lower at 4.88 µg/L comparing with control (24 h) and with the respective concentration at 96 h; and AChE activity in brain was higher at 0.488 and 4.88 µg/L than control (24 h) and the respective concentrations at 96 h, while in muscle it was higher at 0.488 and 4.88 µg/L than control (96 h) and the respective concentrations at 24 h. The present findings demonstrate that, despite IMY+IMI targets the animal-absent AHAS enzyme, such formulation displayed an acute toxic effect upon R. quelen homeostasis by impacting on vital functions such as immune defense, metabolism, ionoregulation and neurotransmission.

Hematological, morphological, biochemical and hydromineral responses in Rhamdia quelen sedated with propofol.

Rhamdia quelen morphophysiological responses to propofol sedation were examined. The purpose was to investigate whether propofol would be a suitable drug to be used in fish transport procedures. Fish were exposed to 0, 0.4 or 0.8 mg L(-1) propofol for 1, 6 or 12 h in 40 L tanks, simulating open transport systems. Propofol was able to prevent the peak of cortisol levels experienced by the group exposed to 0 mg L(-1) propofol at 1 h. At 0.4 mg L(-1), propofol also preserved the stability of hematological (hematocrit, red blood cell count, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration), morphological (red blood cell area), biochemical (cortisol, glucose, lactate, total protein, ammonia, urea, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase) and hydromineral (Na(+), Cl(-) and K(+) plasma levels) indicators of stress. Such results suggest that sedation with propofol at 0.4 mg L(-1) is suitable for R. quelen transport.

Ocorrência de protozoários gastrintestinais em primatas mantidos em cativeiro na região sul do Brasil / Occurrence of gastrointestinal protozoa in primates kept in captivity in the Southern region of Brazil

Este trabalho visou avaliar o parasitismo gastrintestinal por protozoários em macacos mantidos em cativeiro na região Sul do Brasil. Foram analisadas amostras de fezes de 18 primatas de quatro espécies, Cebus apella, Macaca mulata, Callithrix jacchus e Callithrix penicillata pelo método de centrífugo flutuação com sulfato de zinco. Nos animais avaliados, foram verificados infecções simples e mistas pelos protozoários dos gêneros Cryptosporidium, Giardia, Cystoisospora e Balantidium. Analisando a água oferecida aos primatas foi detectada a presença elevada de oocistos de Cryptosporidium spp..

This research aimed at evaluating the gastrointestinal parasitism by protozoa in monkeys kept in captivity in the Southern region of Brazil. Fecal samples from 18 primates of the species Cebus apella, Macaca mulata, Callithrix jacchus and Callithrix penicillata were analyzed by the zinc sulphate centrifugal flotation method. Simple and mixed infections by protozoa of the genus Cryptosporidium, Giardia, Cystoisospora and Balantidium were observed. The water offered to the primates had elevated presence of oocysts of Cryptosporidium spp..