Totals of 158 corn and corn-based samples and 291 wheat and wheat-based samples from Shandong province, China in 2017 were analyzed for five mycotoxins including beauvericin (BEA), enniatin A (ENA), enniatin A₁ (ENA₁), enniatin B (ENB), and enniatin B₁ (ENB₁) by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). BEA was the predominant toxin detected, followed by ENB, ENA₁, ENA, and ENB₁. Corn and corn-based samples were more easily contaminated by BEA with an average concentration of 65.26 µg/kg, compared with that in wheat and wheat-based samples (average = 0.41 µg/kg). Concentrations of BEA, ENA, and ENB₁ in corn kernels, flours, and flakes were significantly different (Kruskal–Wallis Test, p < 0.05), as well as for BEA, ENA, ENB, and ENB₁ in wheat kernels, flours, and noodles (Kruskal–Wallis test, p < 0.05). Furthermore, 59.5% (94/158) and 59.8% (174/291) corn- and wheat-based samples were co-contaminated by at least two mycotoxins, respectively. Positive correlations in concentrations were observed in corn between levels of ENA and ENB₁, ENA and ENB, ENA₁ and ENB₁, as well as in wheat between BEA and ENA, BEA and ENA₁, BEA and ENB, BEA and ENB₁, ENA and ENA₁, ENA and ENB, ENA and ENB₁, ENA₁ and ENB, ENA₁ and ENB₁, and ENB and ENB₁. These results demonstrate that co-contamination of BEA and enniatins (ENNs) in corn- and wheat-based samples from Shandong, China is very common. More data on the contamination of five mycotoxins in cereal and cereal-based samples nationwide are needed.

A total of 769 wheat kernels collected from six provinces in China were analyzed for beauvericin (BEA) and four enniatins (ENNs), namely, ENA, ENA₁, ENB and ENB₁, using a solid phase extraction (SPE) technique with ultra-high performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). The results show that the predominant toxin was BEA, which had a maximum of 387.67 μg/kg and an average of 37.69 μg/kg. With regard to ENNs, the prevalence and average concentrations of ENB and ENB₁ were higher than those of ENA and ENA₁. The geographical distribution of BEA and ENNs varied. Hubei and Shandong exhibited the highest and lowest positive rates of BEA and ENNs (13.46% and 87.5%, respectively). However, no significant difference was observed among these six provinces. There was a co-occurrence of BEA and ENNs, and 42.26% of samples were simultaneously detected with two or more toxins. Moreover, a significant linear correlation in concentrations was observed between the four ENN analogs (r range: 0.75~0.96, p < 0.05). This survey reveals that the contamination and co-contamination of BEA and ENNs in Chinese wheat kernels were very common.

A total of 181 citrus-based products, including dried fruits, canned fruits, and fruit juices, collected from China and from abroad in 2021 were analyzed for the four Alternaria toxins (ALTs): alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), and tenuazonic acid (TeA) via ultra-high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UPLC-ESI-MS). Although the concentrations of the four ALTs varied by product and geographically, TeA was the predominant toxin followed by AOH, AME, and TEN. Products made in China showed higher levels of ALTs than those made abroad. Maximum levels of TeA, AOH, and AME in analyzed domestic samples were 4.9-fold, 1.3-fold, and 1.2-fold, respectively, higher than those in imported products. Furthermore, 83.4% (151/181) of the analyzed citrus-based products were contaminated with at least two or more ALTs. There were significant positive correlations between AOH and AME, AME and TeA, and TeA and TEN in all analyzed samples. More importantly, the solid and the condensed liquid products had higher concentrations of ALTs than the semi-solid product samples, as well as tangerines, pummelos, and grapefruits compared to the other kinds of citrus-based products. In conclusion, co-contamination with ALTs in commercially available Chinese citrus-based products was universal. Extensive and systematic surveillance of ALTs in citrus-based products, both domestic and imported, is required to obtain more scientific data for the determination of the maximum allowable concentrations of ALTs in China.

A total of 470 edible vegetable oil samples including peanut, soybean, rapeseed, sesame seed, corn, blend, and others collected from eight provinces of China were analyzed for the concentrations of beauvericin (BEA), enniatin A (ENA), A₁ (ENA₁), B (ENB), and B₁ (ENB₁) by ultraperformance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS). Concentrations of BEA, ENB, and ENB₁ (average = 5.59 μg/kg, 5.16 μg/kg, and 4.61 μg/kg) in all positive samples were higher than those for ENA and ENA₁ (average = 0.85 μg/kg and 1.88 μg/kg). Frequencies of BEA and ENNs in all analyzed samples were all higher than 50% with the exception of ENA₁ (36.6%, 172/470). Levels of BEA and ENNs in all analyzed samples varied based on their sample types and geographical distributions (Kruskal–Wallis test, p < 0.05). The soybean and peanut oil samples were found to be more easily contaminated by BEA and ENNs than other oil samples. Concentrations of BEA and ENNs in samples obtained from Heilongjiang, Shandong and Guizhou were higher than those found in samples from other provinces. Besides, frequencies of mycotoxin co-contaminations were high and their co-contamination types also varied by oil types. BEA-ENA-ENA₁-ENB-ENB₁ was the most commonly found toxin combination type, almost in one third of the analyzed samples (30%, 141/470). Overall, these results indicate that co-occurrence of BEA and ENNs in analyzed Chinese edible vegetable oil samples is highly common, and it is vital to monitor them, both simultaneously and on a widespread level.