Degradation of ochratoxin A in aqueous solutions by electron beam irradiation

Comprehensive Insights into Ochratoxin A: Occurrence, Analysis, and Control Strategies

Ochratoxin A (OTA) is a toxic mycotoxin produced by some mold species from genera Penicillium and Aspergillus. OTA has been detected in cereals, cereal-derived products, dried fruits, wine, grape juice, beer, tea, coffee, cocoa, nuts, spices, licorice, processed meat, cheese, and other foods. OTA can induce a wide range of health effects attributable to its toxicological properties, including teratogenicity, immunotoxicity, carcinogenicity, genotoxicity, neurotoxicity, and hepatotoxicity. OTA is not only toxic to humans but also harmful to livestock like cows, goats, and poultry. This is why the European Union and various countries regulate the maximum permitted levels of OTA in foods. This review intends to summarize all the main aspects concerning OTA, starting from the chemical structure and fungi that produce it, its presence in food, its toxicity, and methods of analysis, as well as control strategies, including both fungal development and methods of inactivation of the molecule. Finally, the review provides some ideas for future approaches aimed at reducing the OTA levels in foods.

Research progress on the application of different preservation methods for controlling fungi and toxins in fruit and vegetable

Fruits and vegetables are susceptible to fungal infections during picking, transportation, storage and processing, which have a high potential to produce toxins. Fungi and toxins can cause acute or chronic poisoning after entering the body. In the field of fruit and vegetable preservation, technologies such as temperature control, modified atmosphere, irradiation, application of natural or chemical preservatives, and edible films are commonly used. In practical applications, according to the types, physiological differences and actual needs of fruits and vegetables, suitable preservation methods can be selected to achieve the effect of preservation and control of fungi and toxins. The starting point of fresh-keeping technology is to delay post-harvest senescence of fruits and vegetables, inhibit the respiratory intensity, and control the reproduction of microorganisms, which is important to control the reproduction of fungi and the production of toxins. From the three directions of physical, chemical and biological means, the article analyses and explores the effects of different external factors on the production of toxins and the effects of different preservation techniques on fungal growth and toxin production in fruits and vegetables, in order to provide new ideas for the preservation of fruits and vegetables and the control of harmful substances in food.

Ochratoxin A: Overview of Prevention, Removal, and Detoxification Methods

Ochratoxins are the secondary metabolites of Penicillium and Aspergillus, among which ochratoxin A (OTA) is the most toxic molecule. OTA is widely found in food and agricultural products. Due to its severe nephrotoxicity, immunotoxicity, neurotoxicity, and teratogenic mutagenesis, it is essential to develop effective, economical, and environmentally friendly methods for OTA decontamination and detoxification. This review mainly summarizes the application of technology in OTA prevention, removal, and detoxification from physical, chemical, and biological aspects, depending on the properties of OTA, and describes the advantages and disadvantages of each method from an objective perspective. Overall, biological methods have the greatest potential to degrade OTA. This review provides some ideas for searching for new strains and degrading enzymes.

Application of Novel Non-Thermal Physical Technologies to Degrade Mycotoxins

Mycotoxins cause adverse effects on human health. Therefore, it is of the utmost importance to confront them, particularly in agriculture and food systems. Non-thermal plasma, electron beam radiation, and pulsed light are possible novel non-thermal technologies offering promising results in degrading mycotoxins with potential for practical applications. In this paper, the available publications are reviewed-some of them report efficiency of more than 90%, sometimes almost 100%. The mechanisms of action, advantages, efficacy, limitations, and undesirable effects are reviewed and discussed. The first foretastes of plasma and electron beam application in the industry are in the developing stages, while pulsed light has not been employed in large-scale application yet.

Effect of ionising irradiation on silver release from polyolefin/silver nanocomposite films into food simulants

Two types of nanocomposite films, polyethylene/silver (PE/Ag) and polypropylene/silver (PP/Ag), were prepared and characterised. Assessment of silver released under the effect of ionising irradiation was performed on the nanocomposite films. The release experiment was carried out by immersing the nanocomposite films in water, 3% acetic acid or 95% ethanol as food simulants and measuring the Ag release from nanocomposite films treated with and without gamma or electron beam irradiation at a dose of 10 kGy. In general, irradiation treatment increased the Ag release regardless of the type of polymer and food simulant. One reason could be radiation-induced metal oxidation at the surface which in turn promoted ion release into food simulants. The oxidising radicals produced by radiation in solution could be another factor speeding up metal oxidation and subsequent ion release. When comparisons were made between the two types of irradiation, greater Ag release into water and 3% acetic acid was observed after electron beam irradiation, while gamma irradiation was likely to induce greater Ag release into 95% ethanol. Such phenomena reveal the influence of different types of radiation on the solutions which in turn affect the Ag release.

Emergence of cold plasma and electron beam irradiation as novel technologies to counter mycotoxins in food products

Today, mycotoxins are considered a serious risk for human health and the economy around the world. Hence, dealing with them in such a way as to minimise damage to food and plant materials has become an important issue. Cold atmospheric plasma and electron beam irradiation are updated and non-thermal technologies, which are recently used in detoxification of mycotoxins. Both of these technologies have several unique features that turn them into efficient methods for degrading mycotoxins. Therefore, the main purpose of the present study is exhibiting the detoxification power of these methods and parameters affecting their activity. Besides, their advantages, generating systems, activity mechanism, and the toxicity of degradation products are also reviewed.

Effect of Ozone and Electron Beam Irradiation on Degradation of Zearalenone and Ochratoxin A

Zearalenone (ZEN) and ochratoxin A (OTA) are key concerns of the food industry because of their toxicity and pollution scope. This study investigated the effects of ozone and electron beam irradiation (EBI) on the degradation of ZEN and OTA. Results demonstrated that 2 mL of 50 μg/mL ZEN was completely degraded after 10 s of treatment by 2.0 mg/L ozone. The degradation rate of 1 μg/mL ZEN by 16 kGy EBI was 92.76%. Methanol was superior to acetonitrile in terms of degrading ZEN when the irradiation dose was higher than 6 kGy. The degradation rate of 2 mL of 5 μg/mL OTA by 50 mg/L ozone at 180 s was 34%, and that of 1 μg/mL OTA by 16 kGy EBI exceeded 90%. Moreover, OTA degraded more rapidly in acetonitrile. Ozone performed better in the degradation of ZEN, whereas EBI was better for OTA. The conclusions provide theoretical and practical bases for the degradation of different fungal toxins.

Effects of pulsed ultrasound at 20 kHz on the sonochemical degradation of mycotoxins

Mycotoxins, such as aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEA) and ochratoxin A (OTA) are toxic secondary compounds that can reduce the quality of many kinds of food and may lead to other ill effects, both in humans and animals. This study aimed to investigate the potential of the ultrasound (US) treatment in the removal of AFB1, DON, ZEA and OTA from aqueous solution and maize by examining degradation rates and influencing factors of ultrasonication, such as the initial concentrations, power intensity, sonication duration, and duty cycle. The results showed that US treatment could simultaneously reduce AFB1, DON, ZEA and OTA effectively in aqueous solution. The degradation of mycotoxins was significantly affected by the ultrasonic intensity (2.2-11 W/cm3) and sonication time range from 10 to 50 min. DON is more stable than AFB1, ZEA, and OTA in the US treatment. It was found that, for the first time to our knowledge, the highest degradation rates of AFB1, DON, ZEA and OTA were attained at a duty cycle of 25%, and they were 96.5, 60.8, 95.9 and 91.6%, respectively. US strategy can be considered as an effective treatment to degrade the mycotoxins in aqueous solutions and food matrix.

Irradiation-catalysed degradation of methyl orange using BaF2-TiO2 nanocomposite catalysts prepared by a sol-gel method

BaF2-TiO2 nanocomposite material (hereinafter called the composite) was prepared by a sol-gel method. The composite surface area, morphology and structure were characterized by Brunauer-Emmett-Teller method, X-ray diffraction analysis and a scanning electron microscopy. The results showed that BaF2 and TiO2 form a PN-like structure on the surface of the composite. Composites were used to catalyse the degradation of methyl orange by irradiation with ultraviolet light, γ-rays and an electron beam (EB). It was demonstrated that the composite is found to be more efficient than the prepared TiO2 and commercial P25 in the degradation of methyl orange under γ-irradiation. Increasing the composite catalyst concentration within a certain range can effectively improve the decolorization rate of the methyl orange solution. However, when the composite material is used to catalyse the degradation of organic matter in the presence of ultraviolet light or 10 MeV EB irradiation, the catalytic effect is poor or substantially ineffective. In addition, a hybrid mechanism is proposed; BaF2 absorbs γ-rays to generate radioluminescence and further excites TiO2 to generate photo-charges. Due to the heterojunction effect, the resulting photo-charge will produce more active particles. This seems to be a possible mechanism to explain γ-irradiation's catalytic behaviour.

Effects of Electron Beam Irradiation on Zearalenone and Ochratoxin A in Naturally Contaminated Corn and Corn Quality Parameters

Zearalenone (ZEN) and ochratoxin A (OTA) are secondary toxic metabolites widely present in grains and grain products. In this study, the effects of electron beam irradiation (EBI) on ZEN and OTA in corn and the quality of irradiated corn were investigated. Results indicated that EBI significantly affected ZEN and OTA. The degradation rates of ZEN and OTA at 10 kGy in solution were 65.6% and 75.2%, respectively. The initial amounts significantly affected the degradation rate. ZEN and OTA in corn were decreased by the irradiation dose, and their degradation rates at 50 kGy were 71.1% and 67.9%, respectively. ZEN and OTA were more easily degraded in corn kernel than in corn flour. Moisture content (MC) played a vital role in ZEN and OTA degradation. High MC was attributed to high ZEN and OTA degradation. The quality of irradiated corn was evaluated on the basis of irradiation dose. L* value changed, but this change was not significant (p > 0.05). By contrast, a* and b* decreased significantly (p < 0.05) with irradiation dose. The fatty acid value increased significantly. The pasting properties, including peak, trough, breakdown, and final and setback viscosities, were also reduced significantly (p < 0.05) by irradiation. Our study verified that EBI could effectively degrade ZEN and OTA in corn. Irradiation could also affect corn quality.

Detoxification of zearalenone and ochratoxin A by ozone and quality evaluation of ozonised corn

Zearalenone (ZEN) and ochratoxin A (OTA) are secondary toxic metabolites of fungi that can contaminate a wide range of food and feedstuff. In this study, the effects of ozone treatment on ZEN and OTA and the quality of ozonised corn are investigated. Ozone significantly affects ZEN and OTA solutions. ZEN was undetectable 5 s after being treated with 10 mg l^-1 ozone. However, OTA was resistant to ozonation with a degradation rate of 65.4% after 120 s of treatment. Moreover, ZEN and OTA solutions were difficult to degrade after being dried by a nitrogen stream. Results showed that ozone effectively degraded ZEN and OTA in corn. The degradation rates of ZEN and OTA in corn increased with ozone concentration and treatment time. The degradation of ZEN and OTA at different ozone concentrations appropriately conformed to first-order kinetics with an R² value > 0.8749. Furthermore, under the same conditions, corn with increased moisture content (MC) (19.6%) was more sensitive to ozone than corn with a low MC (14.1%). When treated with 100 mg l^-1 ozone for 180 min, ZEN and OTA in corn with 19.6% MC decreased by 90.7% and 70.7%, respectively. To evaluate the quality of ozonised corn, subsequent quality experiments were conducted using corn samples treated at different times with 100 mg l^-1 ozone. The MC of corn decreased after ozone treatment. The whiteness and yellowness of the corn increased and decreased with increasing time, respectively. The fatty acid value of the corn increased significantly (p ≤ 0.05) after 180 min of treatment. This study verified that ozone can effectively degrade ZEN and OTA in corn, but slightly affected corn quality.