Marcin Bryła

Occurrence of 26 Mycotoxins in the Grain of Cereals Cultivated in Poland.

The levels of 26 mycotoxins were determined in 147 samples of the grain of cereals cultivated in five regions of Poland during the 2014 growing season. The HPLC-HRMS (time-of-flight) analytical technique was used. An analytical procedure to simultaneously determine 26 mycotoxins in grain was developed, tested and verified. Samples from eastern and southern Poland were more contaminated with mycotoxins than the samples from northern and western Poland. Toxins produced by Fusarium fungi were the main contaminants found. Some deoxynivalenol (DON) was found in 100% of the tested samples of wheat (Osiny, Borusowa, Werbkowice), triticale, winter barley and oats, while the maximum permissible DON level (as defined in the EU Commission Regulation No. 1881/2006) was exceeded in 10 samples. Zearalenone (ZEN), DON metabolites and enniatins were also commonly found. The presence of mycotoxins in grain reflected the prevailing weather conditions during the plant flowering/earing stages, which were favorable for the development of blight. Among all investigated wheat genotypes, cv. Fidelius was the least contaminated, while Bamberka, Forkida and Kampana were the most contaminated. However, the single-factor ANOVA analysis of variance did not reveal (at a statistical significance level α = 0.05) any differences between levels of mycotoxins in individual genotypes. Triticale was the most contaminated grain among all of the tested varieties. ZEN, DON and the sum of 3-acetyldexynivalenol and 15-acetyldeoxynivalenol (3- and 15-ADON) were found in 100% of the tested triticale samples at concentrations within the 4–86, 196–1326 and 36–374 µg·kg−1 range, respectively. Of particular concern was the fact that some “emerging mycotoxins” (enniatins) (in addition to commonly-known and legally-regulated mycotoxins) were also found in the tested triticale samples (enniatin B (Enn-B), enniatin B1 (Enn-B1), enniatin A-1 (Enn-A1), 100% of samples, and enniatin A (Enn-A), 70% of samples). Depending on the toxin, they were found at levels between 8 and 3328 µg·kg−1.

Fumonisins in plant-origin food and fodder – a review

Fumonisins are mycotoxins produced by the Fusarium group of fungi commonly found on crops, mainly on maize. Some data suggest that as much as 25% of world crops may be lost because of mycotoxin contamination. Therefore, researchers in many countries (particularly in those in which relatively large amounts of maize are directly consumed by humans) are concerned with fumonisin levels in plant-origin foodstuffs and feeds available in their local markets. There is no doubt the levels are strongly correlated with the climate conditions prevailing in the region in which the maize was cultivated: the hotter the climate, the more serious the problem. Negative consequences of consumption of fumonisin-contaminated food by humans include an increased risk of oesophagus cancer and decreased body mass growth. In recent years some trials have been undertaken to reduce fumonisin levels in food and feed by the application of isothiocyanates naturally occurring in plants or peptidoglycans isolated from lactic acid bacteria (LAB). The results of these studies suggested that some reduction in contamination levels might be achieved. Additionally, some recent studies indicate that Sphingopyxis sp. bacteria produce enzymes that are able to break down the fumonisin molecule. Some fumonisins present in food may be bound/coupled with other compounds, and therefore difficult to detect. Such complexes in which the toxins are masked or hidden may even be at higher levels than the not-bound (free) molecules. The problem of how to evaluate effectively and efficiently the concentration of fumonisins in various foodstuffs is therefore a real-life challenge for scientists.

Effect of baking on reduction of free and hidden fumonisins in gluten-free bread.

The aim of the present work was to assess the influence of the baking process on the fumonisin content in gluten-free bread. The dough was made using two methods: without sourdough and with sourdough. Fumonisins were determined using high-performance liquid chromatography with ion-trap mass spectrometry. This study showed that the bread baking process caused a statistically significant drop in the mean concentration of free fumonisins: the reduction levels were 30 and 32% for the direct and sourdough-based methods, respectively. The lower reduction after baking was observed for hidden fumonisins: 19 and 10%, respectively. The presence of some compounds (such as proteins or starch) capable of stabilizing fumonisins during the baking process might be responsible for the observed increase in the hidden-to-free ratio from an initial 0.72 in flour to 0.83 in bread made from sourdough and to 0.95 in sourdough-free bread.

Application of molecularly imprinted polymers to determine B1, B2, and B3 fumonisins in cereal products

The aim of this study was to develop an analytical method for qualitative and quantitative determination of the B(1), B(2,) and B(3) fumonisins in cereal products. A LC coupled to an IT-MS was used as the analytical instrument. The AFFINIMIP FumoZON Molecularly Imprinted Polymer SPE cartridges (Polyintell) were used to isolate fumonisins from the analyzed samples and the clean-up step. Statistical parameters evaluated in some validation experiments were as follows: mean recovery 95-106%, precision <17% (expressed as recovery RSD). The developed method was used to determine fumonisins in 49 cereals (42 maize-based and seven wheat-based products). In most cases, concentrations of the studied compounds found in the analyzed samples were low. The highest total concentration of the B(1), B(2), and B(3) fumonisins was found in maize flour samples (range, 26-1102 μg/kg, mean 498 μg/kg).

Application of semi-permeable membrane dialysis/ion trap mass spectrometry technique to determine polybrominated diphenyl ethers and polychlorinated biphenyls in milk fat.

Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are hazardous food contaminants, their maximum legally allowable levels in food and environment are in the low pgg(-1) range. Therefore some highly selective and sensitive analytical methods must be used to determine them. The 96/23/EC Directive implemented by EC Decision of 12 August 2002 requires recovery rate of an analyte at a concentration below 1 ng g(-1) within the 50-120% range at relative standard deviation (RSD) as low as possible. A method to determine low level PCBs and PBDEs in milk fat based on the semi-permeable membrane dialysis/ion trap GC MS technique was developed. Validation experiments proved that the method performance was within bounds set by the currently standing UE regulations. Recovery rates calculated on the basis of labeled internal standards for majority of the studied indicator PCB congeners and PBDE congeners were close to 100% at RSD below 20%. Also, dioxin-like PCBs recovery rates were compatible with the 1883/2006 EC Regulation (80-120%, RSD below 15%). The developed method turned out to be linear within a far broader concentration range than the studied 0.0025-10 pg μL(-1) range entirely sufficient for analyses of PCB and PBDE in milk fat. Within that range coefficient of linear correlation (R(2)) of calibration curves exceeded 0.98.

Effects of pH and Temperature on the Stability of Fumonisins in Maize Products

This paper is a study of the stability of fumonisins in dough based on maize flour prepared in a phosphate buffer with a pH of 3.5, 5.5 or 7.5 and baked at a temperature within the range of 100–250 °C. Buffers with various pH values were tested, since it is well-known that pH may significantly influence interactions of fumonisins with other substances. A standard analytical procedure was used to determine the concentration of free fumonisins. Hydrolysis in an alkaline medium was then applied to reveal the hidden forms, while the total fumonisins concentations was determined in another measurement. The total concentration of fumonisins was statistically higher in pH = 3.5 and pH = 5.5 than the concentration of free fumonisins; no similar difference was found at pH = 7.5. The applied phosphate buffer pH 7.5 may enhance solubility of fumonisins, which would increase extraction efficiency of free analytes, thereby decreasing the difference between concentrations of total and free fumonisins. Hydrolysed B1 fumonisin (HFB1) and partially hydrolysed B1 fumonisin (isomers a and b: PHFB1a and PHFB1b, respectively) were the main investigated substances. For baking temperatures below 220 °C, fumonisins were slightly more stable for pH = 5.5 than for pH = 3.5 and pH = 7.5. In both of these latter cases, the concentration of partially hydrolysed fumonisins grew initially (up to 200 °C) with an increase in the baking temperature, and then dropped. Similar behaviour was observed for free HFB1, which may suggest the following fumonisin degradation mechanism: initially, the tricarballylic acid (TCA) groups are removed from the molecules, and next, the HFB1 molecules disintegrate.

Natural Occurrence of Nivalenol, Deoxynivalenol, and Deoxynivalenol-3-Glucoside in Polish Winter Wheat

The presence of mycotoxins in cereal grain is a very important food safety factor. The occurrence of “masked” mycotoxins has been intensively investigated in recent years. In this study, the occurrence of nivalenol, deoxynivalenol-3-glucoside, and deoxynivalenol in 92 samples of winter wheat from Polish cultivars was determined. The frequency of the occurrence of deoxynivalenol and nivalenol in the samples was 83% and 70%, respectively. The average content of the analytes was: for deoxynivalenol 140.2 µg/kg (10.5–1265.4 µg/kg), for nivalenol 35.0 µg/kg (5.1–372.5 µg/kg). Deoxynivalenol-3-glucoside, the formation of which is connected with the biotransformation pathway in plants, was present in 27% of tested wheat samples; its average content was 41.9 µg/kg (15.8–137.5 µg/kg). The relative content of deoxynivalenol-3-glucoside (DON-3G) compared to deoxynivalenol (DON) in positive samples was 4–37%. Despite the high frequency of occurrence of these mycotoxins, the quality of wheat from the 2016 season was good. The maximum content of DON, as defined in EU regulations (1250 µg/kg), was exceeded in only one sample. Nevertheless, the presence of a glycosidic derivative of deoxynivalenol can increase the risk to food safety, as it can be hydrolyzed by intestinal microflora.

Modified Fusarium Mycotoxins in Cereals and Their Products—Metabolism, Occurrence, and Toxicity: An Updated Review

Mycotoxins are secondary fungal metabolites, toxic to humans, animals and plants. Under the influence of various factors, mycotoxins may undergo modifications of their chemical structure. One of the methods of mycotoxin modification is a transformation occurring in plant cells or under the influence of fungal enzymes. This paper reviews the current knowledge on the natural occurrence of the most important trichothecenes and zearalenone in cereals/cereal products, their metabolism, and the potential toxicity of the metabolites. Only very limited data are available for the majority of the identified mycotoxins. Most studies concern biologically modified trichothecenes, mainly deoxynivalenol-3-glucoside, which is less toxic than its parent compound (deoxynivalenol). It is resistant to the digestion processes within the gastrointestinal tract and is not absorbed by the intestinal epithelium; however, it may be hydrolysed to free deoxynivalenol or deepoxy-deoxynivalenol by the intestinal microflora. Only one zearalenone derivative, zearalenone-14-glucoside, has been extensively studied. It appears to be more reactive than deoxynivalenol-3-glucoside. It may be readily hydrolysed to free zearalenone, and the carbonyl group in its molecule may be easily reduced to α/β-zearalenol and/or other unspecified metabolites. Other derivatives of deoxynivalenol and zearalenone are poorly characterised. Moreover, other derivatives such as glycosides of T-2 and HT-2 toxins have only recently been investigated; thus, the data related to their toxicological profile and occurrence are sporadic. The topics described in this study are crucial to ensure food and feed safety, which will be assisted by the provision of widespread access to such studies and obtained results.

The efficiency of lactic acid bacteria against pathogenic fungi and mycotoxins

Abstract Mycotoxins are produced by some fungal species of the genera Aspergillus, Penicillium, and Fusarium and are common contaminants of a wide range of food commodities. Numerous strategies are used to minimise fungal growth and mycotoxin contamination throughout the food chain. This review addresses the use of lactic acid bacteria, which can inhibit fungal growth and participate in mycotoxin degradation and/or removal from contaminated food. Being beneficial for human and animal health, lactic acid bacteria have established themselves as an excellent solution to the problem of mycotoxin contamination, yet in practice their application in removing mycotoxins remains a challenge to be addressed by future research.