Synergistic Impact of Bioactive Byproduct Extract Leads to Anti-Fusarium and Anti-Mycotoxin Secretion

Fruit byproducts are considered a high source of bioactive molecules, which possess antioxidant activities. These antioxidants play principal functions in mycotoxin reduction. This study aimed to evaluate crude mandarin byproduct extract for its chemical interaction with fungal growth and suppression of mycotoxin production, and to illustrate whether the impact was regarding individual molecules or a synergistic antioxidation process. Extract contents were analyzed for their phenolic, flavonoids, and antioxidant activity. The fatty acid composition and volatile components were determined using the GC apparatus. The influence of the extract evaluated versus the standard phenolics of trans-ferulic and hesperidin were evaluated. The liposome technique was applied to prevent the antioxidant properties of the bioactive extract. The anti-mycotoxigenic effects of the liposomal and non-liposomal extract were determined in fungal media against the standard phenolics. The results manifested ferulic (235.54 ± 3.34 mg/100 g) and hesperidin (492.11 ± 1.15 mg/100 g) as high phenolics in the extract. Limonene was the main volatile (67.54 ± 1.74%), as well antioxidant activities determined in considerable values. The crude extract recorded efficiency as an anti-Fusarium agent, but less than the standard hesperidin applied in fungal media. The bioactive extract recorded possessed a reduction influence on mycotoxin production. The impact may be joining with its fungal inhibition or its component activity with the active groups on the mycotoxin molecule. The formation of liposomal extract enhanced its efficacy in mycotoxin reduction. This enhancement may illustrate its protective properties for antioxidant components of the bioactive extract.

Heat-induced reduction of deoxynivalenol and its modified forms during flaking and cooking of oat

Deoxynivalenol (DON) and its modified forms deoxynivalenol-3-glucoside (DON-3G) and 3-acetyl-deoxynivalenol (3-ADON) are common contaminants in Norwegian oats. In order to provide more information about the fate of these mycotoxins during oat processing, the levels of DON, DON-3G, 3-ADON and the sum of them (total DON) were determined using LC-HRMS/MS at different processing steps. Oat groat was softened by either steaming or conditioning, rolled into flakes of two thicknesses, and subsequently cooked to produce flake porridges. Flour of oat groat (untreated or kilned) was cooked to flour porridges. The flaking process had major effect on the mycotoxin levels in resulting flakes, with significant impact for type of softening regime, but not for flake size. Steam-softening caused the largest reduction of DON, DON-3G and total DON in flakes, retaining 41, 60 and 46%, respectively, compared to oat groat. In contrast, 3-ADON in flakes was most reduced by conditioning, to 29% of the levels in oat groat. Cooking to porridge from flakes did not result in any additional mycotoxin reduction, though significant impact of flake size was shown in the final porridges, with highest reduction of total DON in the porridges originating from steamed thick flakes. Cooking porridge from untreated oat flour gave significant reduction in mycotoxin levels, however not for kilned oat flour which had already undergone reduction during kilning. In conclusion, the study shows that processes involving heat-treatment, i.e. kilning, steaming or cooking, efficiently reduced total DON in oats during flaking and porridge cooking, and reduction is dependent on previous processing steps.

Mycotoxins in oat flakes – changes during production and occurrence on the Czech market

Raw oats are frequently contaminated by fungi producing mycotoxins, and as such, they can pose a health risk to humans regularly consuming oat products. To reveal the effect of particular processing steps on contamination levels in final oat products, two series of samples obtained from an oat flake manufacturer were analysed. Among oat fractions treated, the most significant mycotoxin decrease was demonstrated in cleaning and dehulling steps, where the observed mycotoxin reduction was in the range of 13–75% for monitored mycotoxins, enniatin B, enniatin B1, HT-2 toxin, T-2 toxin, beauvericin and tentoxin. The overall mycotoxin reduction found in final oat flakes was in the range of 65–100%. Furthermore, 20 commercially available oat flakes from the Czech market were analysed. We detected 16 mycotoxins, mainly trichothecenes and emerging enniatins with levels in the interval of 1–156 μg kg^–1. With regard to the current EU legislation, two analysed oat flake products exceeded the maximum limit for ochratoxin A.

Effect of Selected Cooking Ingredients for Nixtamalization on the Reduction of Fusarium Mycotoxins in Maize and Sorghum

Although previous studies have reported the use of nixtamalization for mycotoxins reduction in maize, the efficacy of calcium hydroxide and other nixtamalization cooking ingredients for mycotoxin reduction/decontamination in sorghum and other cereals still need to be determined. The current study investigated the effect of five nixtamalization cooking ingredients (wood ashes, calcium hydroxide, sodium hydroxide, potassium hydroxide, and calcium chloride) on the reduction of Fusarium mycotoxins in artificially contaminated maize and sorghum using liquid chromatography-tandem mass spectrometry. All tested cooking ingredients effectively reduced levels of mycotoxins in the contaminated samples with reduction initiated immediately after the washing step. Except for the calcium chloride nixtamal, levels of fumonisin B1, B2, and B3 in the processed sorghum nixtamal samples were below the limit of detection. Meanwhile, the lowest pH values were obtained from the maize (4.84; 4.99), as well as sorghum (4.83; 4.81) nejayote and nixtamal samples obtained via calcium chloride treatment. Overall, the results revealed that the tested cooking ingredients were effective in reducing the target mycotoxins. In addition, it pointed out the potential of calcium chloride, though with reduced effectiveness, as a possible greener alternative cooking ingredient (ecological nixtamalization) when there are environmental concerns caused by alkaline nejayote.

Pulsed Electric Fields (PEF) to Mitigate Emerging Mycotoxins in Juices and Smoothies

The development of innovative food processing technologies has increased to answer the growing demand to supply of fresh-like products. The aim of the present study is to investigate the effect of pulsed electric fields (PEF) technology on reducing the emerging mycotoxins (enniatins (ENs) and beauvericin (BEA)) contents in juice and smoothie samples. The products of degradation obtained after PEF treatment were identified and their toxicological endpoint toxicities predicted by Pro Tox-II web. Mycotoxin reduction ranged from 43 to 70% in juices and smoothies, but in water the expected effect was lower. The acidified pH increased BEA reduction in water. The degradation products that were produced were the result of the loss of aminoacidic fragments of the original molecules, such as HyLv, Val, Ile, or Phe. Pro Tox-II server assigned a toxicity class I for enniatin B (ENB) degradation products with a predicted LD50 of 3 mg/Kgbw. The other degradation products were classified in toxicity class III and IV.

Fusarium Mycotoxins in Two Hulless Oat and Barley Cultivars Used for Food Purposes

Hulless oats and hulless barley are highly valued for their excellent nutritional attributes and are increasingly being promoted in human nutrition. However, special attention should be paid to the risk of their contamination by Fusarium mycotoxins, as the rate of mycotoxin reduction during processing could be much lower than that for hulled cereals. In the present study, mycotoxin contamination of two cultivars, each of hulless oats and barley suitable for food purposes were studied in a 3-year field trial established in two contrasting environments. The contents of the mycotoxins regulated by law (deoxynivalenol and zearalenone) were low, and the present legal limits for their maximum content in unprocessed cereals were far from being exceeded. The mycotoxins most frequently occurring in hulless barley were enniatins (enniatin B, enniatin B1 and enniatin A1), beauvericin and nivalenol; hulless oats most frequently contained the HT-2 and T-2 toxins, beauvericin and enniatin B. The contents of enniatins and nivalenol were higher in barley than in oats. Close, positive relationships between the contents of the individual enniatins and between enniatins, beauvericin and nivalenol were observed, which implies that co-exposure could enhance the toxic potential of these mycotoxins through synergistic effects. The results highlight the need to pay more attention to the occurrence of enniatins, beauvericine and nivalenol in hulless oats and barley used for food purposes.