Occurrence of deoxynivalenol in maize germs from North China Plain and the distribution of deoxynivalenol in the processed products of maize germs

Global distribution, toxicity to humans and animals, biodegradation, and nutritional mitigation of deoxynivalenol: A review

Deoxynivalenol (DON) is one of the main types of B trichothecenes, and it causes health-related issues in humans and animals and imposes considerable challenges to food and feed safety globally each year. This review investigates the global hazards of DON, describes the occurrence of DON in food and feed in different countries, and systematically uncovers the mechanisms of the various toxic effects of DON. For DON pollution, many treatments have been reported on the degradation of DON, and each of the treatments has different degradation efficacies and degrades DON by a distinct mechanism. These treatments include physical, chemical, and biological methods and mitigation strategies. Biodegradation methods include microorganisms, enzymes, and biological antifungal agents, which are of great research significance in food processing because of their high efficiency, low environmental hazards, and drug resistance. And we also reviewed the mechanisms of biodegradation methods of DON, the adsorption and antagonism effects of microorganisms, and the different chemical transformation mechanisms of enzymes. Moreover, nutritional mitigation including common nutrients (amino acids, fatty acids, vitamins, and microelements) and plant extracts was discussed in this review, and the mitigation mechanism of DON toxicity was elaborated from the biochemical point of view. These findings help explore various approaches to achieve the best efficiency and applicability, overcome DON pollution worldwide, ensure the sustainability and safety of food processing, and explore potential therapeutic options with the ability to reduce the deleterious effects of DON in humans and animals.

An Automatic Immunoaffinity Pretreatment of Deoxynivalenol Coupled with UPLC-UV Analysis

An immunoaffinity magnetic beads (IMBs) based automatic pretreatment method was developed for the quantitative analysis of deoxynivalenol (DON) by ultra-performance liquid chromatography and ultraviolet detector (UPLC-UV). First, N-hydroxysuccinimide-terminated magnetic beads (NHS-MBs) with good magnetic responsivity and dispersibility were synthesized and characterized by optical microscopy, scanning electron microscopy (SEM), and laser diffraction-based particle size analyzer. Then, the amino groups of anti-DON monoclonal antibody (mAb) and the NHS groups of NHS-MBs were linked by covalent bonds to prepare IMB, without any activation reagent. The essential factors affecting the binding and elution of DON were meticulously tuned. Under optimal conditions, DON could be extracted from a real sample and eluted from IMB by water, enabling environmentally friendly and green analysis. Hence, there was no need for dilution or evaporation prior to UPLC-UV analysis. DON in 20 samples could be purified and concentrated within 30 min by the mycotoxin automated purification instrument (MAPI), allowing for automated, green, high-throughput and simple clean-up. Recoveries at four distinct spiking levels in corn and wheat ranged from 92.0% to 109.5% with good relative standard deviations (RSD, 2.1-7.0%). Comparing the test results of IAC and IMB in commercial samples demonstrated the reliability and superiority of IMB for quantitatively analyzing massive samples.

Ruscogenin protects against deoxynivalenol-Induced hepatic injury by inhibiting oxidative stress, inflammation, and apoptosis through the Nrf2 signaling pathway: An In vitro study

Background

Deoxynivalenol (DON) is a trichothecene mycotoxin with demonstrated cytotoxicity in several cell lines and animals, primarily owing to inflammation and reactive oxygen species accumulation. Ruscogenin (RGN), a steroidal sapogenin of Radix Ophiopogon japonicus, has significant anti-thrombotic/anti-inflammatory effects.

Objective:

The aim of this study was to assess the protective role of RGN against DON-induced oxidative stress, which occurs through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and is regulated by phosphoinositide 3-kinases/protein kinase B (PI3K/AKT).

Methods:

The effects were examined using the HepG2 cell line. RGN and DON were suspended in serum-free medium. Cells were seeded onto plates, and then RGN, DON, or both were added over 24 h in triplicates for each group.

Results:

RGN conferred protection against DON-exhibited cytotoxicity against HepG2 cells. RGN pretreatment downregulated the expression of DON-induced TNF-α and COX-2 and the formation of reactive oxygen species in a dose-dependent manner. RGN upregulated the expression of Nrf2 and its antioxidant proteins as well as mRNA levels of HO-1/NQO-1/HO-1/Nrf2. Similarly, treatment with DON + RGN resulted in upregulation of the pI3K/pAKT signaling pathway in a dose-dependent manner. Finally, RGN was also found to inhibit the DON-induced apoptosis by upregulating the levels of cleaved proteins and downregulating the expression of Bcl2.

Conclusion:

The study demonstrates that RGN suppresses hepatic cell injury induced by oxidative stress through Nrf2 via activation of the pI3K/AKT signaling pathway.

The NO-dependent caspase signaling pathway is a target of deoxynivalenol in growth inhibition in vitro

DON is commonly found in foods and feeds; it presents health risks, especially an increase of growth inhibition in humans, particularly infants and young children. However, there are relatively few research studies devoted to the mechanism of DON-mediated growth retardation. Interestingly, our results showed that DON does not cause any significant production of ROS but results in a persistent and significant release of NO with iNOS increasing activity, mitochondrial ultrastructural changes and decreasing ΔΨm. Moreover, the significant decreases in GH production and secretion induced by DON were dose-dependent, accompanied by an increase of caspase 3, 8 and 9, IL-11, IL-lβ and GHRH. NO scavenging agent (haemoglobin) and free radical scavenging agent (N-acetylcysteine) partially reversed mitochondrial damage, and Z-VAD-FMK increased the levels of GH and decreased the levels of caspase 3, 8 and 9, while haemoglobin decreased the levels of caspase 3, 8 and 9, indicating that NO is the primary target of DON-mediated inhibition. Present research study firstly demonstrated that NO is a key mediator of DON-induced growth inhibition and plays critical roles in the interference of GH transcription and synthesis. The current research is conducive to future research on the molecular mechanisms of DON-induced growth inhibition in humans, especially children.

Assessing the Impact of Oil Types and Grades on Tocopherol and Tocotrienol Contents in Vegetable Oils with Chemometric Methods

The consumption of vegetable oil is an important way for the body to obtain tocols. However, the impact of oil types and grades on the tocopherol and tocotrienol contents in vegetable oils is unclear. In this study, nine types of traditional edible oils and ten types of self-produced new types of vegetable oil were used to analyze eight kinds of tocols. The results showed that the oil types exerted a great impact on the tocol content of traditional edible oils. Soybean oils, corn oils, and rapeseed oils all could be well distinguished from sunflower oils. Both sunflower oils and cotton seed oils showed major differences from camellia oils as well as sesame oils. Among them, rice bran oils contained the most abundant types of tocols. New types of oil, especially sacha inchi oil, have provided a new approach to obtaining oils with a high tocol content. Oil refinement leads to the loss of tocols in vegetable oil, and the degree of oil refinement determines the oil grade. However, the oil grade could not imply the final tocol content in oil from market. This study could be beneficial for the oil industry and dietary nutrition.

Effect of Stored Humidity and Initial Moisture Content on the Qualities and Mycotoxin Levels of Maize Germ and Its Processing Products

With high fat and protein content, maize germ is easily infected with fungus and mycotoxins during its storage. The qualities and safety of germ and its processing products may be affected by the storage. However, studies on the effect of storage on quality and polluted mycotoxin level of maize germ are limited. In this study, maize germ was stored with different initial moisture contents (5.03, 9.07, 11.82 and 17.97%) or at different relative humidity (75, 85 and 95%) for 30 days. The quality indices of germ (moisture content and crude fat content) and their produced germ oils (color, acid value and peroxide value) as well as the zearalenone (ZEN) and deoxynivalenol (DON) levels of germ, oils and meals were analyzed. Results showed that maize germ with high initial moisture contents (11.82, 17.97%) or kept at high humidity (95%) became badly moldy at the end of storage. Meanwhile, the qualities of these germ and oils showed great changes. However, the ZEN and DON contents of this maize germ, oils and meals stayed at similar levels (p < 0.05). Therefore, the storage could produce influence on the qualities of germ and oils, but showed limited effect on the DON and ZEN levels of germ and their processing products. According to this study, the storage condition of germ with no more than 9% moisture content and no higher than 75% humidity was recommended. This study would be benefit for the control of germ qualities and safety during its storage.

Zearalenone Removal from Corn Oil by an Enzymatic Strategy

The estrogen-like mycotoxin zearalenone (ZEN) is one of the most widely distributed contaminants especially in maize and its commodities, such as corn oil. ZEN degrading enzymes possess the potential for counteracting the negative effect of ZEN and its associated high safety risk in corn oil. Herein, we targeted enhancing the secretion of ZEN degrading enzyme by Pichia pastoris through constructing an expression plasmid containing three optimized expression cassettes of zlhy-6 codon and signal peptides. Further, we explored various parameters of enzymatic detoxification in neutralized oil and analyzed tocopherols and sterols losses in the corn oil. In addition, the distribution of degraded products was demonstrated as well by Agilent 6510 Quadrupole Time-of-Flight mass spectrometry. P. pastoris GSZ with the glucoamylase signal was observed with the highest ZLHY-6 secretion yield of 0.39 mg/mL. During the refining of corn oil, ZEN in the crude oil was reduced from 1257.3 to 13 µg/kg (3.69% residual) after neutralization and enzymatic detoxification. Compared with the neutralized oil, no significant difference in the total tocopherols and sterols contents was detected after enzymatic detoxification. Finally, the degraded products were found to be entirely eliminated by washing. This study presents an enzymatic strategy for efficient and safe ZEN removal with relatively low nutrient loss, which provides an important basis for further application of enzymatic ZEN elimination in the industrial process of corn oil production.

Combinational Inhibitory Action of Hedychium spicatum L. Essential Oil and γ-Radiation on Growth Rate and Mycotoxins Content of Fusarium graminearum in Maize: Response Surface Methodology

Nowadays, contamination of agricultural commodities with fungi and their mycotoxins is one of the most annoying with regard to food safety and pose serious health risk. Therefore, there is a requisite to propose suitable mitigation strategies to reduce the contamination of fungi and mycotoxins in agricultural commodities. In the present study, combinational inhibitory effect of Hedychium spicatum L. essential oil (HSEO) and radiation was established on growth rate, production of deoxynivalenol (DON) and zearalenone (ZEA) by Fusarium graminearum in maize grains. The HSEO was obtained from rhizomes by hydrodistillation technique and chemical composition was revealed by GC-MS analysis. A total of 48 compounds were identified and major compounds were 1,8-cineole (23.15%), linalool (12.82%), and β-pinene (10.06%). The discrete treatments of HSEO and radiation were effective in reducing the fungal growth rate and mycotoxins content, and the complete reduction was noticed at 3.15 mg/g of HSEO and 6 kGy of radiation. Response surface methodology (RSM) was applied to evaluate the combinational inhibitory effect of HSEO and radiation treatments on fungal growth rate and mycotoxins content. A total of 13 experiments were designed with distinct doses of HSEO and radiation by central composite design (CCD) of Stat-Ease Design-Expert software. In combinational approach, complete reductions of fungal growth, DON, and ZEA content were noticed at 1.89 mg/g of HSEO and 4.12 kGy of radiation treatments. The optimized design concluded that combinational treatments of HSEO and radiation were much more effective in reducing the fungal growth and mycotoxins content compared to their discrete treatments (p < 0.05). Responses of the design were assessed by second-order polynomial regression analysis and found that quadratic model was well fitted. The optimized design has larger F-value and adequate precision, smaller p-value, decent regression coefficients (R² ) and found statistically significant (p < 0.05). In addition, correlation matrix, normal plot residuals, Box-Cox, and actual vs. predicted plots were endorsed that optimized design was accurate and appropriate. The proposed combinational decontamination technique could be highly applicable in agriculture and food industry to safeguard the food and feed products from fungi and mycotoxins.