Ozonation of agri-food products for reducing mycotoxin contamination: challenges in grains and particulates processing.

This study evaluated differences in the efficiency of ozonation process to reduce the natural contamination of two mycotoxins, deoxynivalenol (DON) and zearalenone (ZEN), in wheat grains and particulate products. Three different products were used, each one representing a different structure and mycotoxin distribution: (1) wheat grains, with natural mycotoxin distribution inside and among the grains; (2) homemade pellets, with homogenous mycotoxin distribution; (3) ground homemade pellets, with homogeneous mycotoxin distribution, and smaller particles. The ozonation of naturally contaminated wheat grains did not reduce the concentrations of DON and ZEN. When the variability of contamination among replicates was reduced by the production of homemade pellets showed, the ozonation provides a reduction of 14% of ZEN concentration. Reducing the size of particles by grinding the homemade pellets, a reduction of DON (11%) and ZEN (31%) was observed, which was evidenced by the higher ozone consumption during the process. Therefore, some limitations of ozonation of grains and particulate products, such as particle dimensions and distribution of natural contamination of mycotoxins affect the degradation of DON and ZEN under real conditions. Because of this, further studies to evaluate the effectiveness of ozonation should also be performed in samples naturally contaminated to produce robustness results.

Evaluation of ozone technology as an alternative for degradation of free gossypol in cottonseed meal: a prospective study.

Free gossypol is a toxic compound which naturally occurs in cottonseed and its derivates, affecting animal and possibly human health. Consequently, alternatives for gossypol destruction must be evaluated. This work evaluated the emerging technology of ozone processing for free gossypol destruction in cottonseed meal. Ozonation was carried out in the actual cottonseed meal and also a model system, designed to describe the involved mode of action. The model system consisted of glass pearls beads covered with free gossypol. Ozonation was performed in two ways: as a static process, i.e., without homogenising the sample after placing them in the reactor, and also homogenising it. Ozone degraded free gossypol in all the systems, but reaching different levels. Free gossypol reduction was higher in the model system than the cottonseed meal, and higher in the homogenised processing than the static one: cottonseed meal in homogenised (56%) and static (25%); model system homogenised (98%) and static (80%). The obtained differences suggest a problem of gas penetration in the solid particles, the effect of unexposed surfaces due to contact areas, and the reaction with other organic molecules further than the target. Ozonation is a promising technique for gossypol degradation in cottonseed meal, but additional strategies are needed to optimise the ozonation process and evaluate toxicological aspects.

Ozone technology to reduce zearalenone contamination in whole maize flour: degradation kinetics and impact on quality.

BACKGROUND: Maize is one of the most important cereals. It is used for different purposes and in different industries worldwide. This cereal is prone to contamination with mycotoxins, such as zearalenone (ZEN), which is produced mainly by Fusarium graminearum, F. culmorum and F. equiseti. Toxin production under highly moist conditions (aw > 0.95) is exacerbated if there are alternations between low temperatures (12-14 °C) and high temperatures (25-28 °C). Even if good production practices are adopted, mycotoxins can be found in several stages of the production chain. For this reason, an alternative to reducing this contamination is ozonation. This study evaluated the reduction of ZEN in naturally contaminated whole maize flour (WMF) treated with 51.5 mg L-1 of ozone for up to 60 min. Pasting properties, peroxide value, and fatty acid composition were also evaluated. RESULTS: Zearalenone degradation in ozonated WMF was described by a fractional first-order kinetic, with a maximum reduction of 62.3% and kinetic parameter of 0.201 min-1 in the conditions that were evaluated. The ozonation process in WMF showed a decrease in the apparent viscosity, a decrease in the proportion of linoleic, oleic, and α-linolenic fatty acids, an increase in the proportion of palmitic acid, and an increase in the peroxide value. CONCLUSION: Ozonation was effective in reducing ZEN contamination in WMF. However, it also modified the pasting properties, fatty acid profile, and peroxide value, affecting functional and technological aspects of WMF. © 2019 Society of Chemical Industry.

Aflatoxin B1 and zearalenone in soybeans: occurrence and distribution in whole and defective kernels.

Few studies have addressed the distribution of mycotoxins in soybean and/or their processing fractions. In this study, samples from commercial lots were collected in four Brazilian states. The distribution of mycotoxins in soybean fractions, according to their commercial grading system, namely whole kernels (WK), split, broken and crushed kernels (SBCK), damaged kernels (DK), heat damaged and burned kernels (HDBK), moldy kernels (MK), greenish kernels (GK), foreign material + impurities (FMI), were analyzed using HPLC-FLD. AFB1 and ZEN tested positive in 43.3 and 80%, respectively. The incidence of AFB1 was higher in MK (50%), followed by HDBK (30.4%) and FMI (26.0%). ZEA incidence ranged from 69% (SBCK) to 100% (HDBK). Co-occurrence (53.3%) in at least one fraction was also detected. Brazil is the second world producer of soybeans, which places the country in a very important position. Therefore, the information provided is crucial and timely relevant for the industry and policymakers.

Ozone treatment to reduce deoxynivalenol (DON) and zearalenone (ZEN) contamination in wheat bran and its impact on nutritional quality.

Wheat bran is an important source for human and animal feed. Its nutritional aspects include a high content of fibre and minerals, as well as phenolic compounds that help prevent chronic diseases. However, wheat can be susceptible to contamination by fungus, which can produce mycotoxins such as deoxynivalenol (DON) and zearalenone (ZEN), causing adverse health effects. Therefore, methods should be developed to reduce possible contamination. Ozone can be used for this purpose as it is considered safe and environmental friendly. The aim of this study was to evaluate the reduction of DON and ZEN concentrations in wheat bran using the ozonation process as well as to evaluate the effect of ozonation on the nutritional quality of bran. Considering this, wheat bran naturally contaminated with both DON and ZEN was processed using ozone at different conditions. The nutritional quality of the bran was evaluated after processing considering the following aspects: the total phenolic content and the bran antioxidant capacity (by using both DPPH and ABTS radicals). The results showed that the degradation of ZEN was higher and faster than the degradation of DON, which could be explained by their molecular structures. The total phenolic content and antioxidant capacity of the bran were not affected by the ozonation process, which is preferable from a nutritional point of view. Therefore, ozonation was demonstrated to be a possible method for reducing mycotoxins in wheat bran, although more studies are needed in order to better understand and optimise processing and product quality.

Co-occurrence and distribution of deoxynivalenol, nivalenol and zearalenone in wheat from Brazil.

Fusarium mycotoxins deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) were investigated in wheat from the 2009 and 2010 crop years. Samples (n = 745) from commercial fields were collected in four wheat producing regions (WPR) which differed in weather conditions. Analyses were performed using HPLC-DAD. Contamination with ZEN, DON and NIV occurred in 56, 86 and 50%, respectively. Also, mean concentrations were different: DON = 1046 µg kg(-1), NIV < 100 µg kg(-1) and ZEN = 82 µg kg(-1). Co-occurrence of ZEN, DON and NIV was observed in 74% of the samples from 2009 and in 12% from 2010. Wet/cold region WPR I had the highest mycotoxin concentration. Wet/moderately hot region WPR II had the lowest mycotoxin levels. Furthermore, the mean concentration of each mycotoxin was higher in samples from 2009 as compared with those from 2010. Precipitation during flowering or harvest periods may explain these results.

Aflatoxin M1 in raw milk from different regions of São Paulo state--Brazil.

A total of 635 raw milk samples from 45 dairy farms, from three regions of São Paulo state - Brazil, were evaluated during 15 months for aflatoxin M1 (AFM1). AFM1 was determined by high performance liquid chromatograph with fluorescence detection. AFM1 was detected (>0.003 µg kg(-1)) in 72.9%, 56.3% and 27.5% of the samples from Bauru, Araçatuba and Vale do Paraíba regions, respectively. The mean AFM1 contamination considering all the samples was 0.021 µg kg(-1). Furthermore, the concentration of AFM1 was quite different among Bauru (0.038 µg kg(-1)), Araçatuba (0.017 µg kg(-1)) and Vale do Paraíba (<0.01 µg kg(-1)) regions. Only three samples (0.5%) had higher contamination than the tolerated limit in Brazil (0.50 µg kg(-1)) and 64 samples (10.1%) had a higher contamination than the maximum limit as set by the European Union (0.050 µg kg(-1)). The estimated AFM1 daily intake was 0.358 and 0.120 ng kg(-1) body weight per day for children and adults, respectively.

Gamma irradiation of in-shell and blanched peanuts protects against mycotoxic fungi and retains their nutraceutical components during long-term storage.

Peanut samples were irradiated (0.0, 5.2, 7.2 or 10.0 kGy), stored for a year (room temperature) and examined every three months. Mycotoxic fungi (MF) were detected in non-irradiated blanched peanuts. A dose of 5.2 kGy was found suitable to prevent MF growth in blanched samples. No MF was detected in in-shell peanuts, with or without irradiation. The colors of the control in-shell and blanched samples were, respectively, 44.72 and 60.21 (L *); 25.20 and 20.38 (Chroma); 53.05 and 86.46 (°Hue). The water activities (Aw) were 0.673 and 0.425. The corresponding fatty acids were 13.33% and 12.14% (C16:0), 44.94% and 44.92% (C18:1, ω9) and 37.10% and 37.63% (C18:2, ω6). The total phenolics (TP) were 4.62 and 2.52 mg GAE/g, with antioxidant activities (AA) of 16.97 and 10.36 µmol TEAC/g. Storage time negatively correlated with Aw (in-shell peanuts) or L *, linoleic acid, TP and AA (in-shell and blanched peanuts) but positively correlated with Aw (blanched peanuts), and with oleic acid (in-shell and blanched peanuts). Irradiation positively correlated with antioxidant activity (blanched peanuts). No correlation was found between irradiation and AA (in-shell samples) or fatty acids and TP (in-shell and blanched peanuts). Irradiation protected against MF and retained both the polyunsaturated fatty acids and polyphenols in the samples.

Gamma radiation induced oxidation and tocopherols decrease in in-shell, peeled and blanched peanuts.

In-shell, peeled and blanched peanut samples were characterized in relation to proximate composition and fatty acid profile. No difference was found in relation to its proximate composition. The three major fatty acids were palmitic acid, oleic acid, and linoleic acid. In order to investigate irradiation and storage effects, peanut samples were submitted to doses of 0.0, 5.0, 7.5 or 10.0 kGy, stored for six months at room temperature and monitored every three months. Peanuts responded differently to irradiation, particularly with regards to tocopherol contents, primary and secondary oxidation products and oil stability index. Induction periods and tocopherol contents were negatively correlated with irradiation doses and decreased moderately during storage. α-Tocopherol was the most gamma radiation sensitive and peeled samples were the most affected. A positive correlation was found among tocopherol contents and the induction period of the oils extracted from irradiated samples. Gamma radiation and storage time increased oxidation compounds production. If gamma radiation is considered an alternative for industrial scale peanut conservation, in-shell samples are the best feedstock. For the best of our knowledge this is the first article with such results; this way it may be helpful as basis for future studies on gamma radiation of in-shell crops.

Gamma radiation effects on peanut skin antioxidants.

Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD) soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative properties when added to soybean oil.

Distribution of aflatoxins in corn fractions visually segregated for defects

The aflatoxin distribution in corn fractions obtained after visual segregation for defects in 30 samples, known to be contaminated, was studied. Each sample was passed through a 5.0 mm round holes sieve, graded for defects and then segregated in sound kernels (regular kernels) and non-sound kernels (injured, germinated, fermented, moldy, heated, insect damaged, immature, broken, hollow, fermented up to », discolored, extraneous materials, and injured by other causes), as defined by the Brazilian Official Grading rules for corn. The non-sound kernels showed the highest contamination levels in all samples. The contamination levels of non-sound kernels (20 percent of total weight) ranged from 23 to 1,365 æg/kg of aflatoxins (B1, B2, G1 and G2) and were higher than sound kernels (p<1 percent) ranging from not detected (ND) to 126 æg/kg and in 87 percent of these the aflatoxin contents were lower than 20 æg/kg. Statistically significant correlation indexes were found among the percentage of defective groups like fermented, heated and sprouted kernels or the total injured kernels, and the estimated contamination levels for the sound and non sound fractions. It was concluded that the non-sound kernels fraction, even being small in weight, has contributed with 84 percent of the estimated contamination of the samples. The segregation of the non-sound kernels would favor a reduction in the contamination of corn lots. The poorer quality corn types (types 3 and Bellow Standart) have predominated among samples of the experiment

Disribution of aflatoxins in comtaminated corn fractions segregated by size

The efficiency of segregation, by particle size, in reducing the aflatoxin content of corn lots under the Brazilian conditions was studied. The aflatoxin content, in the corn fractions obtained after sieving thirty contaminated samples, with approximately 3.0 kg each, was determined. The samples were passed through 4.5 mm round-hole sieves and the fractions with particles ü4.5 mm (fraction A) and <4.5 mm (fraction B) and then analyzed for aflatoxins by TLC. The results showed that the distribution of the aflatoxins among the fractions A and B varied from sample to sample. However, the fraction B presented higher content (6 to 1,422 µg/kg) of aflatoxins (P<5 per cent), than samples of fraction A (4 to 389 µg/kg). In spite of that the segregation of this fraction did not reduce significantly the contamination of the samples. This probably occurred because the contribution of the fraction B for the estimated total of the concentration of aflatoxin of the sample was smaller than that of the fraction A, due to the smallest amount of the fraction B in the sample weight total. In spite of being significant for the studied samples the correlation among the percentages of the groups of grains with defects a) burning grains, sprouted, burned and moldy and b) total injured, with the estimated level of contamination for the samples, more studies will be necessary so that better conclusions can be drawn for this correlation.