Ochratoxin A (OTA) is a potent nephrotoxic, hepatotoxic, and teratogenic compound which is a significant mycotoxin contaminates cereals during storage. Aspergillus ochraceus is the most common producer of OTA in cereals and cereal-derived products. Cinnamaldehyde is a natural substance derived from plant cinnamon playing an important role in the reduction of OTA contamination. In this study, the antifungal and antitoxigenic effect of cinnamaldehyde was investigated with its mechanisms of inhibition of fungal growth at the morphological and ultrastructural levels, and inhibition of OTA biosynthesis at the transcriptional level. Significant A. ochraceus growth was inhibited at 0.4–1.6 mmol/L with fumigation. A. ochraceus exposed to 0.4 mmol/L of cinnamaldehyde indicated irreversible harmful morphological and ultrastructural modifications such as the folding of the cell, the loss of integrity of the cell wall, the disruption of plasma membrane, the destruction of the mitochondria, and the absence of intracellular organelles. These alterations may be attributed to its inhibition of enzymatic reactions that regulate cell wall synthesis, thus disturbing the morphogenesis and growth of A. ochraceus. In the presence of cinnamaldehyde, the tested biosynthetic and regulatory genes like pks, nrps, veA, laeA and velB were highly downregulated. Moreover, the downregulation effect of cinnamaldehyde increased proportionally with the concentrations. These results suggest that the decrease of OTA production by cinnamaldehyde is attributed to the downregulation of the transcriptional levels of OTA biosynthetic and regulatory genes besides the inhibition of fungal growth. The study reveals the mechanisms of the antifungal and antitoxigenic activities of cinnamaldehyde against A. ochraceus, and further emphasizes that cinnamaldehyde could be a safe and effective natural agents against OTA contamination during cereals storage.

Deoxynivalenol (DON) is one of the most prevalent food-associated mycotoxins, and is known to cause a variety of adverse health effects on human and animals. Upon oral exposure, the intestine is the main target organ of DON. The current study unraveled that DON exposure (2 mg/kg bw/day or 5 mg/kg bw/day) can significantly reshape the gut microbiota in a mouse model. The study characterized the specific gut microbial strains and genes changed after DON exposure and also investigated the recovery of the microbiota upon either 2 weeks daily prebiotic inulin administration or 2 weeks recovery without intervention after termination of DON exposure (spontaneous recovery). The results obtained reveal that DON exposure causes a shift in gut microorganisms, increasing the relative abundance of Akkermansia muciniphila, Bacteroides vulgatus, Hungatella hathewayi, and Lachnospiraceae bacterium 28-4, while the relative abundance of Mucispirillum schaedleri, Pseudoflavonifractor sp. An85, Faecalibacterium prausnitzii, Firmicutes bacterium ASF500, Flavonifractor plautii, Oscillibacter sp. 1-3, and uncultured Flavonifractor sp. decreased. Notably, DON exposure enhanced the prevalence of A. muciniphila, a species considered as a potential prebiotic in previous studies. Most of the gut microbiome altered by DON in the low- and high-dose exposure groups recovered after 2 weeks of spontaneous recovery. Inulin administration appeared to promote the recovery of the gut microbiome and functional genes after low-dose DON exposure, but not after high-dose exposure, at which changes were exacerbated by inulin-supplemented recovery. The results obtained help to better understand the effect of DON on the gut microbiome, and the gut microbiota’s recovery upon termination of DON exposure.

Post-harvest management of agricultural products is crucial for minimizing spoilage and economic losses. Volatile organic compounds (VOCs) have emerged as effective indicators of early-stage deterioration, offering a promising approach to improving detection methods. This review examines the role of VOCs in spoilage identification, emphasizing key markers such as terpenes, ketones, esters, and aldehydes in fruits, vegetables, grains, and legumes. Various detection techniques-including spectrometry, electronic noses, spectroscopy, and sensor arrays-are evaluated and compared for their potential to assess spoilage and freshness by correlating their limits of detection (LOD) with typical VOC concentrations in agricultural scenarios. Future development trend in VOC research focus on enhancing sensor sensitivity, developing portable detection devices, integrating VOC monitoring with smart systems, and leveraging artificial intelligence for predictive analysis. These advancements aim to optimize post-harvest management strategies and improve food safety through more accurate and timely spoilage detection.

Aflatoxins (AFs) are secondary metabolites produced by plant fungal pathogens infecting crops with strong carcinogenic and mutagenic properties. Dimethylformamide (DMF) is an excellent solvent widely used in biology, medicine and other fields. However, the effect and mechanism of DMF as a common organic solvent against fungal growth and AFs production are not clear. Here, we discovered that DMF had obvious inhibitory effect against A. flavus, as well as displayed complete strong capacity to combat AFs production. Hereafter, the inhibition mechanism of DMF act on AFs production was revealed by the transcriptional expression analysis of genes referred to AFs biosynthesis. With 1% DMF treatment, two positive regulatory genes of AFs biosynthetic pathway aflS and aflR were down-regulated, leading to the suppression of the structural genes in AFs cluster like aflW, aflP. These changes may be due to the suppression of VeA and the subsequent up-regulation of FluG. Exposure to DMF caused the damage of cell wall and the dysfunction of mitochondria. In particular, it is worth noting that most amino acid biosynthesis and glucose metabolism pathway were down-regulated by 1% DMF using Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Taken together, these RNA-Seq data strongly suggest that DMF inhibits fungal growth and aflatoxin B₁ (AFB₁) production by A. flavus via the synergistic interference of glucose metabolism, amino acid biosynthesis and oxidative phosphorylation.

In order to evaluate the potential differences between 3-Ac-DON and 15-Ac-DON in the human intestinal microbial metabolism, human fecal samples were anaerobically cultured in vitro. Quantitative fecal microbiota characteristics were obtained by 16S rRNA sequencing, and the data revealed several genera that may be relevant for the transformation of the acetylated DONs. Significant differences in the level of 3-Ac-DON and 15-Ac-DON conversion were observed among microbiota from different human individuals. 3-Ac-DON could be rapidly hydrolyzed; a ten-fold difference was observed between the highest and lowest in vitro conversion after 4 h. However, 15-Ac-DON was not fully transformed in the 4 h culture of all the individual samples. In all cases, the conversion rate of 3-Ac-DON was higher than that of 15-Ac-DON, and the conversion rate of 3-Ac-DON into DON varied from 1.3- to 8.4-fold that of 15-Ac-DON. Based on in vitro conversion rates, it was estimated that 45–452 min is required to convert all 3-Ac-DON to DON, implying that deacetylation of 3-Ac-DON is likely to occur completely in all human individuals during intestinal transit. However, for conversion of 15-Ac-DON, DON formation was undetectable at 4 h incubation in 8 out of the 25 human samples, while for 7 of these 8 samples conversion to DON was detected at 24 h incubation. The conversion rates obtained for these seven samples indicated that it would take 1925–4805 min to convert all 15-Ac-DON to DON, while the other 17 samples required 173–734 min. From these results it followed that for eight of the 25 individuals, conversion of 15-Ac-DON to DON was estimated to be incomplete during the 1848 min intestinal transit time. The results thus indicate substantial interindividual as well as compound specific differences in the deconjugation of acetylated DONs. A spearman correlation analysis showed a statistically significant relationship between deconjugation of both acetyl-DONs at 4 h and 24 h incubation. Based on the in vitro kinetic parameters and their scaling to the in vivo situation, it was concluded that for a substantial number of human individuals the deconjugation of 15-Ac-DON may not be complete upon intestinal transit.