Marleen Paulick

Effects of Increasing Concentrations of Sodium Sulfite on Deoxynivalenol and Deoxynivalenol Sulfonate Concentrations of Maize Kernels and Maize Meal Preserved at Various Moisture Content

Under moderate climatic conditions, deoxynivalenol (DON) contamination occurs frequently on cereals. Detoxification measures are required to avoid adverse effects on farm animals. In the present study, a wet preservation method with sodium sulfite (Na2SO3) and propionic acid was tested to titrate the optimum Na2SO3-dose for maximum DON reduction of contaminated maize kernels and meal and to examine the interaction between dose and moisture content in dependence on the preservation duration. The DON concentration decreased with increasing amounts of supplemented Na2SO3 and with increasing duration of the preservation period in a bi-exponential fashion. Additionally, the feed structure and moisture content had a significant influence on the decontaminating effect. Variants with 30% moisture content favored higher DON reduction rates compared to 14% moisture, but especially at low moisture contents, DON reduction was more pronounced in maize kernels than in maize meal. In addition to the decrease of DON, a concomitant formation of three different DON sulfonates was observed which differed in their formation pattern over the time course of preservation. The overall results and statistical analysis clarified that Na2SO3 addition of 10 g/kg maize at 30% moisture for eight days was necessary to obtain a complete DON reduction.

Determination of deoxynivalenol sulphonates in cereal samples: method development, validation and application

The first short and simple RP-UHPLC-MS/MS based method for co-determination of the Fusarium mycotoxin deoxynivalenol (DON) and its reaction products upon treatment with sulphur reagents, the DON sulphonates (DONS) 1, 2 and 3, in cereals was developed and validated. Recoveries of extraction from maize, wheat and barley were between 88 and 107%. Matrix effects ranging between 93 and 234% in concentrated extracts and between 99 and 134% in diluted extracts were compensated by quantitation against matrix matched standards. Measurement of concentrated and diluted extracts enabled determination of DONS-1, -2, -3 and DON in cereals in a concentration range from 0.015 to 120 mg/kg. The method was then applied to investigate the influence of reagent concentration, type of sulphur reagent, moisture content, presence of propionic acid, storage time and thermal treatment in the presence of sodium metabisulphite (SBS) and monomethylamine (MMA) on DON reduction and DONS formation. DON reduction greater than 80% was obtained in several experiments and required storage at moisture contents between 25 and 30% (at reagent concentration of 0.5%) for less than one week, storage with 0.5% SBS at 14% moisture for 6 weeks or thermal treatment in the presence of SBS and MMA. The efficiency of sodium sulphite for DON reduction was systematically compared with that of SBS and found to be lower at 14% moisture content, but similar at 30% moisture. Under most storage conditions, DONS-3 was the main reaction product, followed by DONS-2. Prolonged storage for more than 6-8 weeks shifted the pattern of formed DON sulphonates towards DONS-2. Likewise, thermal treatment in the presence of SBS and MMA caused exclusive formation of DONS-1 and -2. Due to partial degradation of DONS-3 to DON under physiological conditions, predominant conversion of DON into DONS-1 and DONS-2 is desirable.

Studies on the Bioavailability of Deoxynivalenol (DON) and DON Sulfonate (DONS) 1, 2, and 3 in Pigs Fed with Sodium Sulfite-Treated DON-Contaminated Maize

Deoxynivalenol (DON) exposure of pigs might cause serious problems when critical dietary toxin concentrations are exceeded. As DON contamination of agricultural crops cannot be completely prevented, detoxification measures are needed. Wet preservation with sodium sulfite resulted in a significant DON reduction of naturally-contaminated maize in previous experiments. The preserved material had a characteristic DON sulfonates (DONS) pattern. DONS is known to be less toxic than DON but its stability was shown to depend on pH, which gives rise to the question if a back-conversion to DON occurs in vivo. Therefore, the toxicokinetics and bioavailability of DON and DONS were studied in pigs. After the administration of a single oral or intravenous bolus of DON or DONS, serial blood samples were collected and subsequently analyzed. DONS was not detectable after oral administration of DONS mixtures. The results showed further that the bioavailability of DONS as DON in pigs fed maize preserved wet with sodium sulfite was significantly decreased compared to untreated control maize (DON), indicating that DONS obviously did not convert back to DON to a large extent in vivo. Moreover, the fact that DONS was not detectable in systemic blood requires further investigations regarding their ingestive and/or metabolic fate.

Effects of oral exposure to sodium sulphite-treated deoxynivalenol (DON)-contaminated maize on performance and plasma concentrations of toxins and metabolites in piglets

ABSTRACT The objective of the present study was to demonstrate the efficiency of the decontamination process applied to deoxynivalenol (DON)-contaminated maize by sodium sulphite (Na2SO3) treatment in vivo. Additionally, in vitro characterisation of the toxicity of the DON sulphonates (DONS 1, 2 and 3 denote structurally different forms), the resulting DON metabolites, on peripheral blood mononuclear cells (PBMC) should substantiate the inactivation of DON. In a piglet experiment, both DON-contaminated maize and -uncontaminated control maize either untreated (DON−, CON−) or Na2SO3-treated (DON+, CON+) were mixed into feed and fed for 42 d starting from weaning. The results showed that feed intake and daily weight gain of animals fed DON− were significantly lower compared to animals fed CON− and CON+, whereas group DON+ reached the control level or even exceeded it. The feed-to-gain ratio was unaffected (p = 0.45). Furthermore, DON concentrations in plasma markedly reflected the diets’ DON concentrations. These were < 0.1, < 0.1, 5.4 and 0.8 mg/kg feed for CON−, CON+, DON− and DON+, and amounted to 0.3, 0.4, 33.0 and 9.3 ng/ml in plasma, respectively. Whereas DONS 2 and 3 were detected in the DON+ diet, only DONS 2 was recovered in plasma. Regarding the toxicity of DONS, no or much lower toxicity was found compared to DON. DONS 1 and Na2SO3 did not affect the viability of PBMC. At 32.71μM DONS2 the viability was reduced by 50% and thus this compound was less toxic than DON by a factor of 73. Consequently, wet preservation of maize with Na2SO3 was an effective tool to avoid the adverse effects of DON on performance of piglets.

Detoxification of Fusarium-contaminated maize with sodium sulphite – in vivo efficacy with special emphasis on mycotoxin residues and piglet health

ABSTRACT A feeding experiment with piglets was performed to examine the efficacy of a wet preservation of Fusarium (FUS)-contaminated maize with sodium sulphite (SoS) based on deoxynivalenol (DON) and zearalenone (ZEN) residue levels in urine, bile and liquor and health traits of piglets. For this purpose, 80 castrated male piglets (7.57 ± 0.92 kg BW) were assigned to four treatment groups: CON− (control diet, with 0.09 mg DON and <0.01 mg ZEN/kg diet), CON+ (diet CON−, wet-preserved with 5 g SoS/kg maize; containing 0.05 mg DON and <0.01 mg ZEN/kg diet), FUS− (diet with mycotoxin-contaminated maize; containing 5.36 mg DON and 0.29 mg ZEN/kg diet), and FUS+ (diet FUS−, wet-preserved with 5 g SoS/kg maize; resulting in 0.83 mg DON and 0.27 mg ZEN/kg diet). After 42 d, 40 piglets (n = 10 per group) were sampled. A clear reduction of DON levels by approximately 75% was detected in all specimens of pigs fed diet FUS+. ZEN was detected in all urine, bile and liquor samples, while their metabolites were only detectable in urine and bile. Additionally, their concentrations were not influenced by SoS treatment. Among the health-related traits, feeding of FUS diets increased the total counts of leukocytes and segmented neutrophil granulocytes irrespective of SoS treatment. SoS treatment increased the total blood protein content slightly with a similar numerical trend in albumin concentration. These effects occurred at an obviously lower level in FUS-fed groups. Moreover, SoS treatment recovered the reduction of NO production induced by feeding diet FUS− indicating an effect on the redox level. As this effect only occurred in group FUS+, it is obviously related to the adverse effects of the Fusarium toxins. In conclusion, treatment of FUS-contaminated maize with SoS decreased the inner exposure with DON as indicated by the lower DON levels in various piglet specimens. However, health-related traits did not consistently reflect this decreased exposure.

Effects of a Fusarium Toxin-Contaminated Maize Treated with Sodium Sulfite on Male Piglets in the Presence of an LPS-Induced Acute Inflammation

We investigated the effects of feeding sodium sulfite (SoS) treated uncontaminated and Fusarium contaminated maize in a porcine lipopolysaccharide (LPS) challenge model. Eighty piglets (7.59 ± 0.92 kg body weight [BW]) were equally assigned to one of four experimental diets containing 10% maize, either uncontaminated and untreated (CON−, 0.09 mg deoxynivalenol [DON]/kg diet) or uncontaminated and SoS-treated (CON+, wet-preserved with 5 g SoS/kg maize; 0.05 mg DON/kg diet), or prepared with 10% of a Fusarium contaminated maize containing mainly deoxynivalenol (DON), either contaminated and untreated (FUS−, 5.36 mg DON/kg diet), or contaminated and SoS-treated (FUS+, wet-preserved with 5 g SoS/kg maize; 0.83 mg DON/kg diet). At day 42 of experiment, ten pigs of each group were injected intraperitoneally with either 7.5 µg LPS/kg BW or placebo (0.9% NaCl). At 120 min after injection, blood samples were collected to analyse TNF-α, hematological profile, clinical biochemistry as well as the redox status. A significant increase in body temperature and cytokine TNF-α concentration was observed in the LPS-injected piglets. Results for hematology, clinical chemistry and redox status indicate no effects of SoS treatment, with exception of neutrophil counts being significantly more pronounced after feeding the SoS treated FUS maize. In conclusion, SoS treatment of maize did not modulate the LPS-induced acute inflammation.