Occurrence of four mycotoxins in cereal and oil products in Yangtze Delta region of China and their food safety risks

A total of 76 cereal and oil products collected from Yangtze Delta region of China were analyzed for occurrences of aflatoxins (AFs), aflatoxin B₁ (AFB₁), ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZEN). The mycotoxins were determined by the standard detection procedures using immunoaffinity column clean-up coupled with fluorometer (or HPLC-UV). ZEN was the most prevalent toxin, with the incidence of 27.6% (range = 10.0–440.0 μg kg⁻¹), and 9.2% of the evaluated samples were contaminated with a concentration higher than that of the legislation limit of China (60 μg kg⁻¹). AFs and AFB₁ were detected in 14.5% of the samples analyzed, the concentrations ranging 1.1–35.0 μg kg⁻¹ for AFs, and 1.0–32.2 μg kg⁻¹ for AFB₁; 4.0% of the samples had the concentrations of AFs and AFB₁ higher than that of the corresponding legislation limits of China (5.0, 10.0 and 20.0 μg kg⁻¹ for different products). OTA was detected in 14.5% of the cereal and oil products collected; the concentrations ranged 0.51–16.2 μg kg⁻¹. Only 2 samples showed OTA levels higher than that of the legislation limit of China (5.0 μg kg⁻¹). DON was detected in 7.9% of the samples; the concentrations ranged 100–700 μg kg⁻¹, and none of the samples showed DON concentration higher than that of the legislation limit of China (1.0 mg kg⁻¹). A total of 15.8% cereal and oil products were contaminated with at least two mycotoxins (multiple contaminations with different combinations including AFs-ZEN, AFs-OTA-ZEN, OTA-ZEN, ZEN-DON, OTA-ZEN-DON). The dietary exposure assessment results indicated that AFs (AFB₁), OTA, DON and ZEN from cereal-based products represented a series health risk to both adults and children in Yangtze Delta region of China. This is the first report of safety evaluation associated with major mycotoxins for the area.     

Performance modelling of a network processor using POOSL

The increasing complexity of innovative real-time hardware/software systems forced industry to consider system-level design methods. Before actually implementing a system with hardware and software components, system-level design methods enable analysing the performance of different design alternatives that realise the required functionality. In order to develop performance models early in the design process, the parallel object-oriented specification language (POOSL) can be used. POOSL is an expressive modelling language for analysing complex real-time distributed hardware/software systems. Being equipped with a formal semantics, POOSL ensures unambiguous execution of models and proper application of performance analysis techniques. This paper discusses the use of POOSL for analysing the performance of a network processor. A network processor consists of components that perform their behaviour in a synchronously concurrent way, whereas POOSL is based on an asynchronous modelling paradigm. In this paper, we illustrate that constructing abstract models of synchronous systems for the purpose of performance analysis may benefit from an asynchronous modelling approach.     

Fluorescent detection of clenbuterol using fluorophore functionalized gold nanoparticles based on fluorescence resonance energy transfer

A new fluorescence method for detecting clenbuterol based on gold nanoparticles (AuNPs) and rhodamine B (RB) has been developed. It has been observed that the quenching of fluorescence of RB occurs in the present of AuNPs through the fluorescence resonance energy transfer (FRET). In the presence of clenbuterol, the FRET-based fluorescence of RB and AuNPs would be gradually recovered for the reason that clenbuterol could congregate the AuNPs and inhibit the FRET process. An assay for the determination of clenbuterol has been proposed based on the modulation in FRET efficiency between RB and AuNPs. Under the optimum conditions, the fluorescence recovery efficiency of the assay is proportional to the concentration of clenbuterol. The detection limit in swine feed was calculated to be 0.008 mg/g and the recoveries were in the range of 97%–102%. In short, the proposed method provides advantages such as rapidity, simplicity, low cost and high sensitivity, making it promising for the rapid screening of clenbuterol residues.     

High-stability conducting polymer-based conformal electrodes for bio-/iono-electronics

Compared to conventional rigid electronics, polymer-based soft electronics conformal to organisms of irregular shapes have emerged as the next-generation devices, especially benefiting long-term bio-interface interactions that avoid mechanical mismatch and consequent adverse immune responses. Highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has become a promising candidate for building soft conductors/electrodes due to its good conductance, tunable mechanical stiffness, good biocompatibility and facile fabrication into various structures. However, their high instability towards alkaline, reductants and applied voltage has not yet been fully addressed, which inevitably leads to deteriorated performance in complex physiological environments or weather conditions (e.g., humidity). Such intolerances are rooted in unstable electronic/molecular structures of PEDOT caused by de-doping. Besides the low electrical stability, PEDOT:PSS films also exhibit an impaired overall conductance due to its phase separation into PSS-rich and PEDOT-rich domains. Herein, a general and effective coating strategy is proposed, based on a mechanism of simultaneous molecular rejection and electron conjugation, to improve the stability and boost the conductance. Specifically, a reduced-graphene-oxide (rGO) thin layer can not only protect PEDOT: PSS from being de-doped by alkali, bio-reductants and applied voltage through molecular rejection, to maintain its conductivity and ensure stable functions, but also further boost the overall conductance through a bridging effect with its large conjugated domain. This strategy is compatible with various material fabrication techniques, including blade-coating, dip-coating and extrusion-based printing techniques, enabling the fabrication of conductors/electrodes with different structures. Finally, the advantages of excellent stability and high conformability of the composite films as soft conductors have been demonstrated through practical applications in tissue stimulation, electrophysiological recording and proprioceptive hydrogel skins, exhibiting great promise in bio/iono-electronics and human–machine interactions.     

Effects of starch damage and yeast fermentation on acrylamide formation in bread

The effects of starch damage and yeast fermentation on the formation of acrylamide in wheat bread were studied. Four wheat cultivars were milled separately by three laboratory mills to obtain wheat flours with damaged starch content ranging from 1.7 to 6.6%. Reducing sugar contents increased with increasing damaged starch content in flour. Yeast fermentation decreased greatly the content of asparagine by 40–60% in the dough, but increased substantially the content of reducing sugar. Compared with the unleavened bread, dough fermentation significantly decreased the content of acrylamide in leavened bread. The content of acrylamide in bread increased with increasing damaged starch content in wheat flours from the same cultivar. This study clearly showed that damaged starch content in wheat flour and dough fermentation are two major determinants of the formation of acrylamide in bread. The mitigation of acrylamide formation in bread can be achieved by reducing damaged starch in flour and by fermentation of the dough.     

Ontological modelling of content management and provision

Information provision to address the changing requirements can be best supported by content management. The current information technology enables information to be stored and provided from various distributed sources. To identify and retrieve relevant information requires effective mechanisms for information discovery and assembly. This paper presents a method, which enables the design of such mechanisms, with a set of techniques for articulating and profiling users’ requirements, formulating information provision specifications, realising management of information content in repositories, and facilitating response to the user’s requirements dynamically during the process of knowledge construction. These functions are represented in an ontology which integrates the capability of the mechanisms. The ontological modelling in this paper has adopted semiotics principles with embedded norms to ensure coherent course of actions represented in these mechanisms.     

A study on the occurrence of aflatoxin M1 in raw milk produced in Sarab city of Iran

The presence of aflatoxin M1 (AFM1) in 111 samples of raw milk obtained from dairy plants of Sarab city of Iran were analysed. In 85 of the 111 samples (76.6%) the presence of aflatoxin M1 was detected in conc. ranging between 0.015 and 0.28 μg/l. AFM1 level in (40%) of positive samples were higher than the maximum tolerance limit (0.05 μg/l) accepted by some European countries.The lowest mean of AFM1 concentration was found as 0.024 μg/l on August, and the highest AFM1 value as 0.118 μg/l on December. Incidence level of AFM1 on January, February, April, and December, was higher than the other months.Statistical evaluations showed that mean contamination level of AFM1 in autumn and winter samples were significantly higher (P < 0.01) than those of spring and summer.In addition the results showed that there were no statistical differences between AFM1 contents of spring and summer samples.     

Antioxidant activities of cultivated and wild Korean ginseng leaves

Cultivated and wild ginseng leaves were examined for their various antioxidant activities. Both ginseng leaves were extracted with methanol and sequentially partitioned with solvents in an order of increasing polarity. Among various solvent extracts in cultivated and wild ginseng leaves, EtOAC extracts in both ginseng leaves showed the most powerful scavenging activities against DPPH radicals. Data on other antioxidant activities, measured by inhibition rates against lipid peroxidation and linoleate oxidation, revealed similar results, showing the highest activities in EtOAC extracts, followed by butanol, water, chloroform and hexane extracts, in both cultivated and wild ginseng leaves. EtOAC extracts of wild ginseng leaves contained more phenolics (9.71 g:4.87 g/100 g, dry basis) and flavonoids (3.03 g:2.34 g/100 g, dry basis) than cultivated ginseng leaves. When EtOAC extracts were acid-hydrolyzed, two aglycones of flavonoids, quercetin (0.43 and 0.66 g/100 g, dry basis) and kaempferol (1.23 and 1.50 g/100 g, dry basis) were detected in cultivated and wild ginseng leaves. These differences in concentrations of key antioxidants between two different ginseng leaves seemed to be responsible for their differences in antioxidant activities.