Decontamination of aflatoxin B1‐contaminated corn by ammonium persulphate during fermentation

The decontamination of aflatoxin B₁(AFB₁)‐contaminated corn, which is required if the corn is to be suitable for alternative use, by an ammoniation–fermentation integrated process was studied. This process could be used for the production of fuel ethanol from aflatoxin‐containing corn. Different concentrations (0.25, 0.50, 1.00, 1.5 and 2.0% w/w) of ammonium persulphate were tested in the detoxification of AFB₁‐contaminated corn during fermentation. In order to increase the decontamination of corn, 0.5 and 1.0% (w/w) azodicarbonamide, benzoyl peroxide and hydrogen peroxide were tested. Peroxides were added at three different stages of the fermentation process: liquefaction, saccharification and fermentation. Levels of AFB₁ and ethanol were determined after each fermentation process. Treated corn was tested for mutagenic potential using the Ames test with TA100 tester strain and pure AFB₁ as positive control. Addition of 2.0% (w/w) ammonium persulphate caused the highest level of decontamination without affecting ethanol production. Addition of peroxides did not significantly (P < 0.05) increase ethanol production or significantly (P < 0.05) improve the decontamination process. The best processes for decontamination of corn and for ethanol production included the addition of 2.0% (w/w) ammonium persulphate for both and of 1.0 and 0.5% (w/w) benzoyl peroxide respectively. All treated corn samples showed no mutagenic potential. Possible industrial use of these processes is discussed. © 2002 Society of Chemical Industry     

Treatment of saline wastewater contaminated with hydrocarbons by the photo-Fenton process

The application of the photo-Fenton process to the treatment of saline wastewater contaminated with hydrocarbons is investigated. Aqueous saline solutions containing raw gasoline were used as a model oil-field-produced water. The dependence on concentrations of the following reagents has been appropriately evaluated: hydrogen peroxide (100-200 mM), iron ions (0.5-1 mM), and sodium chloride (200-2000 ppm). The reactions were monitored by measurement of the absorption spectra and total organic carbon (TOC). Experimental results demonstrate that the photo-Fenton process is feasible for the treatment of wastewaters containing hydrocarbons, even in the presence of high concentrations of salt. The effect of the salt in this process is described through a series of reactions. A simple feedforward neural network model was found to correlate well the observed data for the degradation process.     

Quantitative determination of fluorotelomer sulfonates in groundwater by LC MS/MS

Aqueous film-forming foams (AFFF) are complex mixtures containing fluorocarbon- and hydrocarbon-based surfactants that are used to fight hydrocarbon-fueled fires. The military is the largest consumer of AFFF in the United States, and fire-training activities conducted at military bases have led to groundwater contamination by unspent fuels and AFFF chemicals. A direct-injection, liquid-chromatography tandem mass spectrometry (LC MS/MS) method was developed to quantify a suite of fluorotelomer sulfonate surfactants in groundwater collected from military bases where fire-training activities were conducted. The 4:2, 6:2, and 8:2 fluorotelomer sulfonates were detected and quantified in groundwater from two of the three military bases. The total fluorotelomer sulfonate concentrations observed at Wurtsmith AFB, MI, and Tyndall AFB, FL, ranged respectively from below quantitation (< or = 0.60) to 182 microg/L and from 1100 to 14,600 microg/L. Analyses of a fluorotelomer-based AFFF concentrate by negative ion fast atom bombardment/mass spectrometry and LC MS/MS analyses indicate that the AFFF concentrate contains only a small amount of fluorotelomer sulfonates and that fluoroalkylthioamido sulfonates are the main anionic fluorosurfactant in the mixtures. More research is needed to determine the fate of fluoroalkylthioamido sulfonates in the environment.     

A possible structure of the casein micelle based on high-resolution field-emission scanning electron microscopy

New electron micrographs, produced using the technique of Field Emission Scanning Electron Microscopy, showing the details of the micellar surface, are presented. The images show the micellar surfaces without any coating, and suggest that the surface of the micelle may have a much more complex structure than has previously been demonstrated. Although there appear to be no spherical subunits (submicelles), there is evidence for the organization of the caseins into tubular structures within the micelle. The surface is not smooth, and contains gaps between the substructures. The observations are discussed in terms of published models of micellar structure, where is it suggested how the depiction of the micellar surface can be used to explain certain factors of its reactivity and behaviour.     

Quantification of ethyl carbamate in cachaça produced in different agro‐industrial production systems

Popularly known by various names such as caninha, dangerous, drips, damned and many other denominations, cachaça is the genuine Brazilian drink, produced by the fermentation of sugarcane juice by yeast, followed by distillation in alambics. Considering that cachaça is the most widely consumed distilled beverage from Brazil, the knowledge of the chemical composition and the presence of potentially toxic compounds such as ethyl carbamate, considered a human carcinogen, is important. The aim of this study was to evaluate the influence of different conditions of the agro‐industrial cachaça production systems, including the variety of sugarcane, on the quantification of ethyl carbamate through the chromatographic. Thirteen unaged beverage samples, produced from different varieties of sugarcane, were analysed. Using analysis of variance and comparison of average concentrations of ethyl carbamate (Scott–Knott, α = 5%), all of the samples were found to contain contaminant levels below the ceiling established by the legislation, which is 210 µg L^?1. Copyright © 2016 The Institute of Brewing & Distilling     

Hydrogenation of brown coal. 2. Iron-based catalysis

Some of the inherent cations of Victorian brown coals have been exchanged for iron by treatment with solutions of iron salts. Coals with various iron contents are obtained by variation of the pH of the solutions used. Hydrogenation of coals treated in this way at 395 °C, and an initial hydrogen pressure of 10 MPa, give product yields similar to those obtained using commercial cobalt molybdate on alumina catalysts, and greater than those obtained using red mud as a catalyst. The increase in yields compared with non-catalysed experiments results mainly from increased production of asphaltenes. The amount and composition of gas (80–90 wt% C0₂, resulting from decarboxylation) remains constant. Despite the similar conversions, the hydrogen consumption and tetralin/naphthalene ratios for iron-catalysed experiments are less than for cobalt—molybdate-catalysed experiments.     

Influence of Heat Pretreatments of Oat Grain on the Viscosity of Flour Slurries

Heat treatment of oat grain had significant effects on the viscosity of flour slurries. Steamed oats produced highly viscous flour slurries, whose viscosity increased with time, whereas the viscosity of flour slurries produced from raw or roasted (104°C for 120 min) oats was much lower and degraded rapidly. Slurry viscosity was correlated with (1→3), (1→4)-β-D -glucan concentration in the flours and treatment of slurries with lichinase lowered viscosity significantly. Effects of steaming were partially reversed by roasting treatment and vice versa. Mixtures of equal amounts of raw and steamed flour resulted in slurries more viscous than either flour alone, but that viscosity degraded after 3 h to less than the mean viscosity of the steamed and raw controls. Water-soluble extracts from steamed flour had about twice the viscosity of raw or roasted flour extracts, but contained only 80% of the (1→3), (1→4)-β-D -glucan present in those extracts. Molecular weight analysis of soluble carbohydrates from raw, roasted and steamed soluble extracts indicated the molecular weight of β-glucans in these extracts was similar. However, if extracts were made from slurries that had incubated for 3 h, extensive degradation of β-glucans was evident in raw and roasted samples. It is likely that enzymic degradation of (1→3),(1→4)-β-D -glucans is responsible for much of the decreased raw and roasted flour slurry viscosity over extended time periods, but different heat treatments appear to also affect (1→3), (1→4)-β-D -glucan polymer interaction. © 1997 SCI.     

Defining the public health threat of food fraud

Food fraud, including the more defined subcategory of economically motivated adulteration, is a food risk that is gaining recognition and concern. Regardless of the cause of the food risk, adulteration of food is both an industry and a government responsibility. Food safety, food fraud, and food defense incidents can create adulteration of food with public health threats. Food fraud is an intentional act for economic gain, whereas a food safety incident is an unintentional act with unintentional harm, and a food defense incident is an intentional act with intentional harm. Economically motivated adulteration may be just that-economically motivated-but the food-related public health risks are often more risky than traditional food safety threats because the contaminants are unconventional. Current intervention systems are not designed to look for a near infinite number of potential contaminants. The authors developed the core concepts reported here following comprehensive research of articles and reports, expert elicitation, and an extensive peer review. The intent of this research paper is to provide a base reference document for defining food fraud-it focuses specifically on the public health threat-and to facilitate a shift in focus from intervention to prevention. This will subsequently provide a framework for future quantitative or innovative research. The fraud opportunity is deconstructed using the criminology and behavioral science applications of the crime triangle and the chemistry of the crime. The research provides a food risk matrix and identifies food fraud incident types. This project provides a starting point for future food science, food safety, and food defense research. PRACTICAL APPLICATION: Food fraud, including the more defined subcategory of economically motivated adulteration, is a food protection threat that has not been defined or holistically addressed. The terrorist attacks of September 11, 2001, led to the development of food defense as an autonomous area of study and a new food protection discipline. As economically motivated adulteration grows in scope, scale, and awareness, it is conceivable that food fraud will achieve the same status as an autonomous concept, between food safety and food defense. This research establishes a starting point for defining food fraud and identifying the public health risks.     

Spatial and seasonal variability of dissolved methylmercury in two stream basins in the eastern United States

We assessed methylmercury (MeHg) concentrations across multiple ecological scales in the Edisto (South Carolina) and Upper Hudson (New York) River basins. Out-of-channel wetland/floodplain environments were primary sources of filtered MeHg (F-MeHg) to the stream habitat in both systems. Shallow, open-water areas in both basins exhibited low F-MeHg concentrations and decreasing F-MeHg mass flux. Downstream increases in out-of-channel wetlands/floodplains and the absence of impoundments result in high MeHg throughout the Edisto. Despite substantial wetlands coverage and elevated F-MeHg concentrations at the headwater margins, numerous impoundments on primary stream channels favor spatial variability and lower F-MeHg concentrations in the Upper Hudson. The results indicated that, even in geographically, climatically, and ecologically diverse streams, production in wetland/floodplain areas, hydrologic transport to the stream aquatic environment, and conservative/nonconservative attenuation processes in open water areas are fundamental controls on dissolved MeHg concentrations and, by extension, MeHg availability for potential biotic uptake.