Malt Samples Research Articles

Functional Properties of Complementary Food from Millet (Pennisetum glaucum), African Yam Bean (Sphenostylis stenocarpa), and Jackfruit (Artocarpus heterophyllus) Flour Blends: A Comparative Study

The progress towards exploring the potentials of underutilized indigenous food sources via product development to curb food wastage and agro-food extinction is a way of attaining food nutrition and security within a region. In this context, a comparative study involving some functional properties of complementary food from some underutilized foods (millet, African yam bean, and jackfruit) was carried out. Briefly, millet, African yam bean, and jackfruit were subjected to series of processing treatments such as malting, pre-gelatinization, drying, and milling, followed by blending into various ratios to obtain different samples of composite flours as a complementary food. From these, the functional properties, that is, water absorption capacity (WAC), loose bulk density (LBD), packed bulk density (PBD), foam capacity (FC), swelling index (SI), dispersibility, wettability, and sinkability were determined. Results showed that malting and pre-gelatinization influenced the intrinsic functional properties of the flour blends. In addition, composite flours containing malted samples had significantly lower (p<0.05) dispersibility, SI, WAC, LBD, and PBD, but significantly higher (p<0.05) wettability and sinkability. The variations in flour substitution showed no impact on the flour functionality except for SI and dispersibility. All composite flours exhibited an appreciable level of functionality and suitability to be used as a complementary food for weaning purposes. Overall, this research has demonstrated the potentials of utilizing millet, African yam bean, and jackfruit as sustainable nutrient-dense food materials for the production of complementary food.

Fate and Behavior of Field-Applied Pesticides during Malting and Mashing Processes.

The present work aimed to study the fate of field-applied pesticides during malting and mashing processes. Twenty-four field-collected barley samples were subject to micromalting followed by lab-scale mashing to investigate the carryover of residual pesticides from barley to malt and then from malt to sweet wort. The citrate-buffered QuEChERS sample preparation method was adapted for simultaneous determination of 57 pesticide residues in grain, malt, spent grains, and sweet wort samples using ultra-performance liquid chromatography coupled with tandem mass spectroscopy (UPLC-MS/MS). Residues of four fungicides (fenpropimorph, pyraclostrobin, tebuconazole, and trifloxystrobin) and two insecticides (chlorpyrifos and pirimiphos-methyl), frequently found in the barley samples, were investigated in detail in this study. The carryover percentages of these pesticides to malt, against the concentration of residues in barley grain, ranged from 22% for pirimiphos-methyl up to 78% for fenpropimorph. The results confirm a general rule that residues of pesticides with log P values >2 remain on the malt, but it was found that their transfer potential is more related to its individual physical-chemical properties but does not much correlate to their log P values. In the second part of the study, a noticeable carryover from malt to sweet wort was observed for pyraclostrobin, fenpropimorph, and tebuconazole residues, and these values ranged from 2 to 15%. Moreover, the analysis of pesticide residues in spent grain after mashing revealed that the spent grain samples contain on average once as much pyraclostrobin and tebuconazole residues as the original malt. It was concluded that (1) pyraclostrobin and tebuconazole residues could be incorporated into or associated with macromolecules in barley grain to form "hidden" (bound) forms, and (2) the parent compounds are subsequently released from their hidden forms during mashing.

English

In the presented investigation, the chemical composition of malt during roasting is estimated using diffuse reflectance mid-infrared fourier transform (DRIFT-MIR) spectroscopy and multiple linear regressions. Accordingly, the corresponding test setup is presented and evaluated. A total number of sixty-five stop roasting, having temperature range from 140 to 220oC, and one unroasted sample of 1500 g Avalon malt are performed in an eddy current roaster. Roasted and unroasted malt samples are milled and then analysed. Additionally, analytical standard reference methods are performed for colour, spectral tristimulus L*a*b* - values, colour difference (DE), iron-content, quantitative radical generation and the formation of specific intermediates, such as 5-(hydroxymethyl) furfural (HMF) as well as 3?deoxy?hexosulose (3-DH) and end products of Maillard reaction on all sixty-six samples. Multiple linear regression models were used to predict analysed references based on mid-infrared data, modified with spectral pre-processing for better prediction performance. The obtained results indicate that DRIFT-MIR spectrometry, combined with pre-processing and selection of evaluated wave number areas, is a useful analytical tool for the measurement of quality attributes of malt and therefore, shows potential for application in quality and process control. Key words: Malt roasting, mid-infrared, optical spectroscopy, process control, EBC, L*a*b*, DE, quality control.

Gushing phenomenon and gene Hyd5 from Fusarium species in barley samples from Brazil

Hydrophobins produced by the Fusarium genus in brewing barley in connection with gushing phenomenon have been studied in many different countries. However, the presence of proteins associated with gushing in grains harvested in Brazil is currently unknown. The surface active class 2 hydrophobin Hyd5 has been identified as a possible causative agent for gushing of beer. For this reason, the objective of this study was to evaluate the presence of Hyd5 in isolated Fusarium strains from Brazilian barley samples. This was followed by gushing tests. The Hyd5 gene was identified in all fungal isolates and phylogenetic analysis exhibited four main linages. Gushing tests demonstrated that among the 21 analysed malt samples 8 were positive considering overfoaming at the bottle opening. Levels ranged from 8 to 124 g/bottle of gushing. No correlation between phylogenetic analysis and gushing was observed when they were evaluated together. This is due to positive isolates for gushing which are scattered throughout the phylogenetic tree. The other cause may be that all main clades contain at least one positive isolate for gushing. More research regarding hydrophobins and gushing should be carried out in the future due to the fungi isolated in Brazilian samples. These results offer excellent support that could help the brewing industry to prevent its losses and to provide further understanding of the gushing phenomenon in beer.

Tumor Cell Microenvironment and Microvessel Density Analysis in MALT Type Lymphoma.

MALT type lymphoma belongs to marginal zone lymphoma (MZL). MALT lymphomas' inflammatory microenvironment contributes to the pathogenesis of this cancer. In this study, we analyzed and quantified the tumor inflammatory microenvironment in MALT lymphoma samples and in healthy controls, and the microvessel content by immunohistochemistry and morphometric estimation. Biopsy specimens from MALT type lymphoma patients and from non-metastatic axillary lymph nodes (CTRL) were analyzed by immunochemistry in order to quantify CD3, CD4, CD8, CD68, CD163, tryptase, CD34, and Ki67 positive cells. A substantial increase in the number of cells that were positive for the above markers and microvascular density (MVD) were observed in the MALT group. We also found a positive correlation between microvessels and CD8+ cells and between CD8+ cells and M2 type macrophages, while tryptase+ mast cells correlated with CD4+ cells. The mitotic proliferation index Ki67 was higher in MALT samples. The interactions between inflammatory cells in the tumor microenvironment and their correlation with angiogenesis is a useful tool in the development of new immunotherapy strategies.

Combined effect of high temperature and drought on yield and malting quality of barley

Spring barley varieties Tolar and Marthe were grown under the standard conditions and stress conditions with a combined effect of high temperature and drought in three experiments conducted in the greenhouse of phytotron type. The results showed that growing under the stress conditions led to reduced yield, grain quality and malt quality. This effect was observed both in the individual years and on average for the entire study period. Average yield of grain declined by ca 53% and retention above 2.5 mm screen decreased by ca 28% (P = 0.001). Further, average content of proteins rose by 3.7% while starch content decreased by 5.1% (P = 0.01). In malt samples, average extract and friability were reduced by 5.8% and 15%, respectively, and average protein content increased by 3.8% (P = 0.01). The growing conditions were a dominant factor in the conducted experiments.

Monitoring the evolution of free and cysteinylated aldehydes from malt to fresh and forced aged beer

During storage, beer staling coincides with a gradual increase in the concentrations of aldehydes resulting in the appearance of undesirable flavours. Cysteinylated aldehydes, also referred to as 2-substituted 1,3-thiazolidine-4-carboxylic acids, have been proposed as potential precursors of this increase. This study aimed to further understand the origin of aldehydes in aged beer, by monitoring both free and cysteinylated aldehydes throughout the brewing process, from the raw materials until the stored product. Quantification of free and cysteinylated aldehydes was performed for two different brews via headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), respectively. All selected marker aldehydes were quantified in malt, wort, and the resulting fresh and aged beer samples. Cysteinylated aldehydes were quantifiable in malt and up to the wort boiling phase. The highest levels of free aldehydes were found in malt, whereas cysteinylated aldehydes showed highest levels at mashing-in pointing to their formation during both malting and subsequent mashing-in. During beer ageing, an increase in all free aldehydes was measured. In particular, a rise in 2-methylpropanal and furfural is most striking. Although the presented experimental data obtained on malt and brewery samples do support the concept of bound-state aldehydes, cysteinylated aldehydes cannot be consider as the cause of increasing levels of staling aldehydes during beer ageing.

Maillard Reaction Products in Different Types of Brewing Malt.

Individual Maillard reaction products (MRPs), namely, free and protein-bound glycated amino acids as well as dicarbonyl compounds, were quantitated in various types of brewing malt using chromatographic means. Among the protein-bound glycated amino acids, which were analyzed following enzymatic hydrolysis, N-ε-fructosyllysine was the dominating compound in light (EBC < 10) and dark (10 < EBC < 500) malts, accounting for up to 15.9% of lysine derivatization, followed by N-ε-maltulosyllysine (light malts, up to 4.9% lysine derivatization) or pyrraline (dark malts, up to 10.4% lysine derivatization). Roasting of malt led to the degradation of most of the protein-bound glycated amino acids. The same trends were visible for free glycated amino acids. A novel MRP-derived Strecker aldehyde, namely, 5-(2'-formyl-5'-hydroxymethylpyrrol-1'-yl)-pentanal (pyrralinal), was detected in dark malt. The most abundant 1,2-dicarbonyl compound in malt samples was 3-deoxyglucosone (up to 9 mmol/kg), followed by 3-deoxymaltosone (up to 2 mmol/kg). Only few MRPs such as 5-hydroxymethylfurfural, furfural, the dicarbonyl compounds glyoxal, methylglyoxal, and diacetyl as well as protein-bound rhamnolysine and MG-H1 correlated with the malt color. A comparison of MRPs present in malt with corresponding amounts in beer points to neoformation of MRPs such as MG-H1 and 3-deoxygalactosone during the brewing process.

Comparison of Physicochemical Properties and Metabolite Profiling Using 1H NMR Spectroscopy of Korean Wheat Malt.

The objective of this study was to compare the physicochemical, enzymatic, and metabolic properties of two control wheat malts imported from Germany and the US to those of malts made from three Korean wheat varieties: Triticum aestivum L., var. Anzunbaengi, Jokyung, and Keumkang. The qualities and enzyme activities of the Korean wheat malts were generally similar to those of the control wheat malts. The Korean wheat malts had slightly lower diastatic power and enzyme activities related to saccharification. The analysis of metabolites in the wheat malt samples was performed using 1H nuclear magnetic resonance (NMR) metabolomics, which identified 32 metabolites that differed significantly among the samples. Most amino acids and lipids were more abundant in the Korean wheat malts than in the control wheat malts. These differences among malts could influence the quality and flavor of wheat beers. Further brewing studies are necessary to identify the association between beer quality and individual malt metabolites.

Detection of mycotoxins in opaque beer production

In Zimbabwe opaque beer is one of the most common alcoholic beverages. This study was aimed at detecting aflatoxins and Ochratoxin A (OTA) in commercial opaque beer brewing. Aflatoxins and OTA are mycotoxins produced by fungi. Maize, sorghum malt and opaque beer samples were used for microbiological plating and multi mycotoxin extraction. Aflatoxins, OTA, Aspergillus spp, total viable count, coliforms, Lactobacillus spp, Salmonella, Shigella, Staphylococcus aureus were assessed. Mycotoxins were separated using an High Performance Liquid Chromatography (HPLC). Aflatoxins were not detected in all the samples. OTA concentration for malt was 18 μg/kg, 5.2 μg/kg in beer and absent in maize. Fungi identified in maize were Aspergillus flavus, Aspergillus niger, Aspergillus carbonarius, and Aspergillus fumigatus. Malt contained Aspergillus flavus and Aspergillus carbonarius. Fungi observed in beer were Aspergillus flavus and Aspergillus niger. The beer may need heat treatment methods in order to remove the microorganisms identified and prolong shelf life of the product.

Quantitative and Qualitative Composition of Bacterial Communities of Malting Barley Grain and Malt during Long-Term Storage

In the grain samples of three malting barley varieties harvested in 2016, and in the malt made from them, we observed microbial changes during storage. Analyses were performed after 0, 3, 6, and 9 months of storage in floor warehouses and silos. We monitored microbial changes based on the quantitative determination of microorganisms using a plate dilution method and qualitative determination of microorganisms, where we identified a particular species of bacteria using the MALDI-TOF MS Biotyper instrument (Bruker Daltonics, Bremen, Germany). Based on the quantitative determination of microorganisms, we found that the total plate counts of microorganisms was higher in malts than in barley grains. The storage period had the greatest impact on the number of coliform bacteria, which gradually increased with the growing months in storage. The number of lactic acid bacteria in barley grains with the growing months in storage and malt produced from them decreased slightly, and the content of the sporulating bacteria in all the samples fluctuated slightly. Differences in the numbers of observed microorganisms were negligible during storage between floor warehouses and silos. In the samples of barleys, the most commonly identified species were Pantoea agglomerans, which was also present in malt samples but did not belong to the dominant species. A diverse species representation appeared in the samples, whereas predominating species belonged to the Enterobacteriaceae family.

Profiling the volatile carbonyl compounds of barley and malt samples using a low-pressure assisted extraction system

In this work, an analytical methodology for the analysis of volatile carbonyl compounds in barley and malt samples is presented. A simple low-pressure extraction system for volatile compounds was developed. This analytical tool enabled the extraction of volatile compounds directly from barley or malt solid samples (15 min extraction, 10.0 g sample) to an acceptor derivatizing liquid solution, thereafter analyzed by HPLC-DAD-ESI-MS/MS. The low-pressure conditions, pressure of 20 ± 2 in. Hg vac. (33.7 ± 3.7 kPa), enabled to increase the efficiency of the extraction process of some volatile compounds up to 3-fold comparing to normal conditions. Also, no heating procedures were applied, avoiding possible sample degradation and adulteration. Barley and different malt samples, namely pilsner, caramel, chocolate and black, were evaluated. Relevant differences were observed in the volatile carbonyl compounds profile between the samples analyzed. Specialty malts showed richer volatile profiles comparing to barley and pilsner malt samples. Some marker compounds, such as hydroxyacetone and furfural responsible for caramellic, burnt and bready flavours, could be assigned for the most intensely roasted malt samples. In comparison, 2- methylbutanal and 3-methylbutanal were characteristic for caramel malt. The results herein obtained showed that this analytical methodology could be a valuable analytical tool in the characterization, as well as in the quality control of these important raw materials during the malting and roasting processes.

Determination of Cytolytic Malt Modification – Part II: Impact on Wort Separation

The cytolytic malt criteria viscosity and β-glucan are used as an integral part of routine laboratory control measures to classify the malt modification level and to ensure good processability. Part one of this two-part publication demonstrated that barley varieties with high cytolytic modification along with low β-glucan content tend to have a higher content of usually unconsidered water-soluble arabinoxylan. This study investigated the arabinoxylan molar mass distribution and its impact on processability. In order to observe the impact of arabinoxylans on separation processes in the brewhouse, lautering tests of different modified malt types were performed. The results suggest that in contrast to their lower β-glucan content, highly modified malt types had a higher average arabinoxylan content (767 mg/L) than medium modified samples (710 mg/L). Furthermore, differentiation of arabinoxylan molar mass resulted in a higher molar mass of 14–34% above 50 kDa in these samples. In terms of processability, flux through the spent grain cake was mainly influenced by wort viscosity (r=-0.621, p < 0.01), although arabinoxylan had little influence on the viscosity. However, 53% of highly modified malt samples had a flux of less than 4 L/h × m2 (average value) despite low β-glucan levels. A principal component analysis identified arabinoxylans as the main driving force in connection with the permeability through the filter cake, whereby especially highly modified barley varieties (60%) were affected. Arabinoxylans may have a decisive effect, so it is not only β-glucan as a structural cell wall substance and present viscosity that should be considered as determining quality characteristics.

Влияние условий замачивания ячменя на содержание белковых веществ в солоде

Introduction. Malt production requires low-protein barley. Unfortunately, bad environmental conditions often lead to higher protein content than specified in the related standards. The research objective was to study the effect of barley steeping conditions on the level of albuminous substances in malt and to assess the possibility of reducing nitrogenous substances by changing the steeping regime. &#x0D; Study objects and methods. The research featured two varieties of barely, namely “Primorsky 89” and “Primorsky 98”. Both varieties were harvested in 2013, 2015, and 2016 in the Primorye Region of Russia. The protein content in the grain of each variety differed significantly, depending on the year of harvest, and ranged from 1.75% to 2.5%. Two micromalting modes differed only in the steeping time and were performed at 17°C. The malt samples were analyzed for total protein content, total soluble nitrogen, Kolbach Index, and free amino nitrogen. &#x0D; Results and discussion. The “Primorsky 89” variety proved insensitive to a longer steeping time, thus maintaining the same characteristics of the malt. The decrease in the protein level in the malt compared to the raw material was approximately the same for each mode and amounted to 0.3%. The Kolbach Index ranged between 30.31% and 35.1%. The experiment failed to produce the desired degree of dissolution, while the difference in this indicator under various modes was less than 1%. The long steeping mode proved optimal for the “Primorsky 98” variety. An increase in the steeping time made it possible to reduce the content of nitrogenous substances in the malt by 1%, compared to the raw material. Higher initial protein content in the grain resulted in lower content of nitrogenous substances during malting. The long steeping mode also resulted lowered the Kolbach Index by 3%: it was 34.7% – 39.5% for the long steeping mode and 31.1–36.8% for the short steeping mode. &#x0D; Conclusion. The barley variety and the malting method affected the dynamics of nitrogenous substances. For some varieties, a longer steeping period proved to reduce the content of nitrogenous substances in the malt and increase the Kolbach Index.

Reuse of regenerated immunoaffinity column for excellent clean-up and low-cost detection of trace aflatoxins in malt

The high price of the immunoaffinity column (IAC) has limited its broad application in the cleanup of analytes from complex matrices. This study aimed to reduce practical cost by regenerating IACs for reuse in cleaning up and purifying aflatoxin (AF) B1, B2, G1 and G2 from medicinal and edible malt samples, followed by high-performance liquid chromatography coupled with photochemical derivatization and fluorescence detection (HPLC-PCD-FLD). The IACs were prepared in advance by coupling anti-AFs specific antibodies (Abs) on a solid phase carrier. After each use, the IACs were washed immediately with phosphate-buffered saline (PBS) and pure water, respectively, and then were filled with PBS as the preservation solvent for storage at 4 °C overnight to recover the binding activity of the immobilized Abs for the regeneration and reuse in the next day until the recovery rate was lower than 70%. Results showed that the developed HPLC-PCD-FLD method displayed good linearity in wide concentration range with the limit of detection (LOD) and quantification (LOQ) of 0.3125–0.5 ng/mL and 1–1.5 ng/mL for the four aflatoxins, as well as excellent accuracy and precision with relative standard deviations (RSDs) <5.5% and <7.0%, respectively. The IACs could be used at least nine times for AFB2, AFG1, and AFG2 when intruding the recommended method in Huaan Magnech Bio-Tech IAC instructions for raw malt sample preparation. And the corresponding consumption could be reduced to one-ninth of the original cost. Due to the high toxicity and incidence of AFB1, the IACs were suggested for reuse twice regarding this aflatoxin in malt with half of the original cost. The reuse of the regenerated IACs for excellent clean-up and low-cost detection of trace AFs in complex matrices is economical, green and environment-friendly, expecting widespread application of more mycotoxins in sophisticated food and traditional Chinese medicine matrices with low cost.

Effects of Malting on Nutritional Characteristics of Pigeon Pea (Cajanus cajan)

Background/Objective: Malting is a process that is not expensive and is technologically effective in improving the nutritional quality of food. The objective of this study was to determine the effect of malting on the nutritional characteristics of pigeon pea (Cajanus cajan).&#x0D; Materials and Methods: The pigeon pea seeds were sorted and washed. The seeds were then steeped in water at 29°C for 24 hours. Changing of water at 6 hours interval was observed during steeping. The resultant steeped seeds were spread on jute bag and were covered with white cotton cloth to germinate for 72 hours. The sprouted seeds were oven dried at a temperature of 50°C for 1 hour and thereafter, the plumules were separated from the seed and the malted seeds were dried and milled into flour. Both the raw and malted samples were subjected to laboratory analysis for proximate, mineral element composition, anti-nutrients and functional properties. The results were determined in triplicate and subjected to statistical analysis using SPSS version 20.&#x0D; Results: The result of the proximate analysis showed that the samples were generally low in moisture which are 12.81±0.07 and 15.10±0.81%, protein content are 19.01±0.08 and 22.10±0.16%, Ash content are 2.27±0.23 and 3.18±0.47%, Fat content are 1.02±0.32 and 1.68±0.81%, fibre content are 0.45±0.52 and 1.23±0.63%, carbohydrate are 57.37±0.28 and 63.78±0.01% and energy were 300.32 and 326.20 Kcal/100 g for raw and malted sample respectively. The result of minerals are iron 0.13±0.12 and 1.03±0.08 mg/100 g, magnesium 50.30±0.01 and 68.24±0.45 mg/100 g, zinc 0.27±0.21 an 0.88±0.32 mg/100 g, phosphorus 13.10±0.57 and 18.30±0.32 mg/100 g, potassium 2.10±0.62 and 4.50±0.08 mg/100 g, sodium 6.10±0.31 and 9.33±0.07 mg/100 g and calcium 7.28±0.41 and 10.11±0.22 mg/100 g for raw and malted sample respectively. The anti-nutrients determined are phytate 19.86±0.03 and 7.22±0.78 mg/100 g, oxalate 1.78±0.03 and 0.02±0.42 mg/100 g, trypsin inhibitor 40.53±0.42 and 10.30 m±0.07 g/100 g, tannins 28.80±0.50 and 9.12±0.18 mg/100 g and hydrogen cyanide 1.63±0.68 and 0.68±0.04 mg/100 g, for the raw and malted pigeon pea respectively. The functional properties are Bulk density 0.62±0.81 and 0.98±0.01 g/cm3, water absorption capacity 227.05±0.24 and 261.220.38%, oil absorption capacity 162.72±0.11 and 170.54%±0.42, foaming capacity 18.80±0.28 and 37.73±0.21% and swelling capacity 4.08±0.13 and 6.24±0.31%.&#x0D; Conclusion: It was observed that highly nutritious flour can be produced from pigeon pea using malting.

A self-assembled electrochemical immunosensor for ultra-sensitive detection of ochratoxin A in medicinal and edible malt

Trace residue of mycotoxins in complex medicinal and edible food matrices has brought huge challenges for the development of ultrasensitive analytical methods. Here, a green electrochemical immunosensor for the ultrasensitive detection of ochratoxin A (OTA) was fabricated by self-assembling a compact 2-mercaptoacetic (TGA) monolayer on the surface of the working Au electrode to form the Au/TGA/bovine serum aibumin (BSA)-OTA/anti-OTA monoclonal antibody composite probes for selective and ultra-sensitive detection of OTA based on indirect competitive principle and differential pulse voltammetry analysis. The electrochemical impedance spectroscopy and cyclic voltammetry methods were introduced to characterize the assemble situation of the TGA-modified Au electrode and optimize some critical parameters for the green electrochemical immunoseonsor. Under the optimal conditions, the developed immunosensor exhibited much lower limit of detection (0.08 ng/mL) in the range of 0.1–1.0 ng/mL for OTA compared with other direct or disposable electrochemical immunosensors. Real application in the spiked malt samples verified high accuracy with no matrix interferences of the proposed immunoseonsor. This is a meaningful study on a self-assembled electrochemical immunoseonsor for ultra-sensitive and rapid detection of OTA in malt samples, which suggested a general simple-to-use sensing platform and prospect as an economical and green tool for ultra-sensitive detection of much more trace-level of toxic small molecules in other complex matrices to ensure their quality and safety.

Selected Trichothecenes in Barley Malt and Beer from Poland and an Assessment of Dietary Risks Associated with their Consumption.

Eighty-seven samples of malt from several Polish malting plants and 157 beer samples from the beer available on the Polish market (in 2018) were tested for Fusarium mycotoxins (deoxynivalenol (DON), nivalenol (NIV)), and their modified forms ((deoxynivalenol-3-glucoside (DON-3G), nivalenol-3-glucoside (NIV-3G), 3-acetyldeoxynivalenol (3-AcDON)). DON and its metabolite, DON-3G, were found the most, among the samples analyzed; DON and DON-3G were present in 90% and 91% of malt samples, and in 97% and 99% of beer samples, respectively. NIV was found in 24% of malt samples and in 64% of beer samples, and NIV-3G was found in 48% of malt samples and 39% of beer samples. In the malt samples, the mean concentration of DON was 52.9 µg/kg (range: 5.3–347.6 µg/kg) and that of DON-3G was 74.1 µg/kg (range: 4.4–410.3 µg/kg). In the beer samples, the mean concentration of DON was 12.3 µg/L (range: 1.2–156.5 µg/L) and that of DON-3G was 7.1 µg/L (range: 0.6–58.4 µg/L). The concentrations of other tested mycotoxins in the samples of malt and beer were several times lower. The risk of exposure to the tested mycotoxins, following the consumption of beer in Poland, was assessed. The corresponding probable daily intakes (PDIs) remained a small fraction of the tolerable daily intake (TDI). However, in the improbable worst-case scenario, in which every beer bottle consumed would be contaminated with mycotoxins present at the highest level observed among the analyzed beer samples, the PDI would exceed the TDI for DON and its metabolite after the consumption of a single bottle (0.5 L) of beer.

Nanomodified Screen-Printed Electrode for direct determination of Aflatoxin B1 in malted barley samples

The present work describes a facile synthesis of a nanocomposite based on gold nanoparticles (NPAu) and graphene quantum dots (GQD) and its use as an electrode modifier for a non-biological alternative of Aflatoxin B1 (AFB1) voltammetric determination. TEM and SEM techniques showed a uniform and well-distributed dispersion of gold nanoparticles (19 ± 6 nm of average size) and GQD, which was used as a reducing and stabilizing particle formation. Modified screen-printed electrode (NPAuGQD-SPE) was characterized by electrochemical experiments, as linear voltammetry and electrochemical impedance spectroscopy. A significative electrocatalytic effect was observed towards AFB1 oxidation using the proposed device, shifting the peak potential to less positive values and improving the voltammetric response. EIS experiments showed lower RCT values for the modified electrodes, calculated as 117 Ω, 14.9 kΩ, and 40.3 kΩ for NPAuGQD-SPE, GQD-SPE, and SPE, respectively. Under optimized conditions, an analytical curve with linear region of 1.0–50.0 nmol L−1 was obtained, reaching detection and quantification limits of 0.47 and 1.5 nmol L−1, respectively. Samples of malted barley were fortified based on the maximum residue limit (MRL) allowed by Brazilian legislation, and recoveries in the range of 76–103% were obtained, indicating that there is no significant matrix effect, considering the low concentration values used and simple sample treatment.

The Influence of Steeping Water Change during Malting on the Multi-Toxin Content in Malt.

The aim of this study was to assess the impact of steeping water change and Fusarium graminearum contamination level on different multi-toxin types and concentrations in barley malt. Malt samples were subjected to two micromalting regimes—steeping water change and the other with no steeping water change. Malt was contaminated with different F. graminearum contamination levels (0%, 10%, and 20%). The results indicate that malt with higher F. graminearum contamination levels ensured higher concentrations of toxins. Higher fungal metabolite concentrations were determined in samples exposed to freshly-changed steeping water, especially zearalenone and its derivates whose values were three to four times higher than in samples with no water change. Zearalenone-4-sulfate showed four (in 10% contamination) and even thirty times (in 20% contamination) higher concentrations than in samples with no water change. Water change during malting resulted in higher levels of multi-toxins in the final product.