Mieczysław Obiedziński

Polycyclic aromatic hydrocarbons in the bakery chain

The level of polycyclic aromatic hydrocarbons occurrence and the possibility of their formation in the bakery chain, its raw materials and final products, were examined. Experimental bread baking, with different baking temperatures, was performed in the Warsaw bakery, using cyclothermic deck ovens. PAHs determination was performed by high-pressure liquid chromatography with fluorescent and diode array detectors (HPLC-FLD/DAD) and confirmed by gas chromatography coupled with mass spectrometry (GC/MS). Total content of 19 PAHs in the grain, flour and bran varied from 1.07 to 3.65 μg/kg and, in bread, from 1.59 to 13.6 μg/kg depending on the part of bread and baking temperature. Based on the doughs contamination level and the influence of the baking temperature on the breads PAHs content, it was confirmed that PAHs are formed during baking. Considering the results of the average dietary exposure to PAHs and the MOE (Margin of Exposure) analysis, it could be concluded that analysed bread and cereal products constitute little concern for consumer health.

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).

Seasonal and geographical variations in levels of polychlorinated biphenyls (PCB) and polybrominated diphenyl ethers (PBDE) in Polish butter fat used as an indicator of environmental contamination

The aim of this study was to evaluate the seasonal variation/geographical distribution of environmental concentration of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) across Poland using butter fat as an indicator of the contaminants. The average concentration of six indicator PCBs determined in the studied samples was 1500 pg g–1 fat. The average concentration of 12 dioxin-like PCBs expressed as lower-bound dioxin-equivalent toxicity was 0.684 pg TEQ g−1 fat. The average total concentration of 14 investigated PBDE congeners was 105 pg g−1 fat. Statistically significant concentration differences between summer and winter samples were found. The results of this study indicate also a significant geographical diversification of butter contamination reflecting regional differences in environmental contamination. The seasonal variation of PBDE profiles evidences transformation of PBDE within the environment.

Volatile Profile of Non-Fermented Milk and Milk Fermented by BifidoBacterium animalis subsp. lactis

The aim of this work was to determine low-molecular volatile compounds in milk supplemented with the strain Bifidobacterium animalis subsp. lactis Bb-12 with or without fermentation process, stored at 6°C for 4 weeks. The chromatographic analysis of probiotic-supplemented non-fermented milk and milk fermented by strain Bb-12 revealed the presence of volatile compounds, such as ketones, organic acid, and alcohols. The changes in the volatile profile were influenced by fermentation process and/or prolonged cold storage. The fermentative activity of strain Bb-12 and its intensification between the 2nd and 4th weeks were observed in the cold storage condition of milk.

Phytosterol oxides content in selected thermally processed products

Heat treatments are very popular methods of food preparation in European countries. Phytosterol present in foodstuffs undergoes oxidative changes during heat treatment, and phytosterol oxides (e.g., 7α-, 7β-hydroxysterol, 5α,6α-, 5β,6β-epoxysterol, 7-ketosterol and triol) are formed. Phytosterol oxidation products (POPs) have been associated with cytotoxic and pro-apoptotic effects in humans. On the other hand, several studies conducted on animals revealed that some phytosterol oxides lower serum triacyglycerol and blood glucose levels. The aim of this study was to evaluate the effect of heat treatment on formation of phytosterol oxidation products in selected foodstuffs. The following products were taken into considerations: minced meat (pork and beef), frozen French fries, frozen fish fillets, frozen fish products (e.g., fish sticks), wheat and egg noodles. Sterols and POPs content was evaluated by GC–MS working in total and selected ion monitoring modes. The phytosterol oxidation rate was higher in French fries and fish fillets (0.20–1.69% of total phytosterol content) than in noodles, minced meats and readymade fish products (in 0.04–0.36% range). Method of POPs determination using GC–MS is reported in this study. Results of this study show also that products of the animal origin might be considered as sources of the phytosterol oxides in the human diet.

Non-dioxin-like and dioxin-like polychlorinated biphenyls in butter sampled from the Polish retail market.

The aim was to investigate levels of polychlorinated biphenyls (PCBs) in butter available on the Polish retail market. A gas chromatography-based method was developed for the purpose of this study. An ion-trap mass spectrometer was used as a detection system with high-resolution chromatography. Recoveries of individual PCBs from spiked samples varied from 58% to 105% with a recovery relative standard deviation in the range 3–16%. Levels of eight non-dioxin-like and twelve dioxin-like congeners were determined. Toxic equivalent factors (TEQs) were calculated using World Health Organization (WHO) TEQs. The average concentration of the sum of six PCBs (28, 52, 101, 138, 153, and 180) was found to be 1561 ± 728 pg g−1 (fat) and the upper-bound concentrations of dioxin-like congeners were (1 standard deviation uncertainty) 0.441 ± 0.384 pg PCB-TEQ g−1 (fat).

The profile of volatile compounds in the outer and inner parts of broiled pork neck is strongly influenced by the acetic-acid marination conditions

Raw pork neck cutlets were marinated in an aqueous solution of acetic acid (pH4, 24h, 4°C) without (M) or with 1% (w/w) of glucose. The control (K) was formed by non-treated raw pork neck. The cutlets were then broiled (185°C, 30min). In all K cutlets, significant higher amounts of volatile compounds (VCs) were developed after broiling than the other samples. Significant more aldehydes and alcohols were present in the inner parts than in the surface. The correlation between surface and internal layers was high only for aldehydes. Marinating decreased the differences among VCs and led to the standardization of the processed meat. The addition of glucose to the marinade led to more volatile aldehydes, carboxylic acids, esters, furan, pyran, pyrazine, pyrrol and pyridine derivatives than in M samples. Several (53) specific VCs explained the differences among the surface samples related to the marinating process. However, only 16 VCs explained the variance among the inner parts.

Occurrence of biogenic amines in beers produced with malted organic Emmer wheat (Triticum dicoccum)

Because several groups of microorganisms are able to decarboxylate amino acids, the presence of biogenic amines (BA) can be seen as an index of the microbiological quality of the brewing process. BAs were quantified for the first time in the intermediate products and craft beers produced with malted organic Emmer wheat (Triticum dicoccum) in a small size brewery in order to assess the possible presence of critical control points related to biological hazard in the brewing process. BA levels in beers produced exclusively from malted organic Emmer wheat were between 15.4 and 25.2 mg l–1 in the samples of light beer (Lt) and between 8.9 and 15.3 mg l–1 in double malt beers (DM) ready for consumption (the beers stored for 90 days at 1–2°C). Cadaverine and tyramine were the main BAs in the Lt and DM beers, respectively. Increased concentrations of BAs seemed to be more related to the heat treatment of the processing product during mashing and wort boiling, rather than to the fermentation process. Much lower concentrations were found in finished beers obtained from 50% malted organic Emmer wheat and 50% malted barley (up to 3.2 mg l–1) or from 30% malted Emmer wheat (up to 8.3 mg l–1). Thus, Emmer wheat malt can be a useful alternative to wheat and spelt for the production of beer with a limited content of BA, if the processing technology is kept under control.