Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds

The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems

Food Coloring Agents and Plant Food Supplements Derived from Vitis vinifera: A New Source of Human Exposure to Ochratoxin A

Grape pomaces are increasingly being used as starting material in the industrial production of plant food supplements (PFS), food coloring, and tartrates, but they are at risk of ochratoxin A (OTA) contamination, a mycotoxin with nephrotoxic and carcinogenic effects. We analyzed 24 commercial PFS and 13 food coloring samples derived from Vitis vinifera, mainly pomaces, using a HPLC−FLD method for OTA determination. OTA was found in 75% of PFS samples and 69% of food coloring samples at levels of <1.16−20.23 μg/kg and <1.16−32.00 μg/kg, respectively. The four commercial leavening agents containing tartrates were found to be negative for OTA. All eight samples collected in two distilleries that use grape pomaces and wine lees to produce tartrates and other byproducts contained OTA at levels of <1.16−240.93 μg/kg. The high incidence of OTA contamination in PFS and food coloring agents derived from V. vinifera suggests that maximum permitted level(s) should be established for this mycotoxin in these products

Efficacy of a Mycotoxin Binder against Dietary Fumonisin, Deoxynivalenol, and Zearalenone in Rats

It was hypothesized that a mycotoxin binder, Grainsure E, would inhibit adverse effects of a mixture of fumonisin B1, deoxynivalenol, and zearalenone in rats. For 14 and 28 days, 8–10 Sprague–Dawley rats were fed control diet, Grainsure E (0.5%), toxins (7 μg fumonisin B1/g, 8 μg of deoxynivalenol/g and 0.2 μg of zearalenone/g), toxins (12 μg of fumonisin B1/g, 9 μg of deoxynivalenol/g, and 0.2 μg of zearalenone/g + Grainsure E), or pair-fed to control for food intake of toxin-fed rats. After 28 days, decreased body weight gain was prevented by Grainsure E in toxin-fed female rats, indicating partial protection against deoxynivalenol and fumonisin B1. Two effects of fumonisin B1 were partly prevented by Grainsure E in toxin-fed rats, increased plasma alanine transaminase (ALT) and urinary sphinganine/sphingosine, but sphinganine/sphingosine increase was not prevented in females at the latter time point. Grainsure E prevented some effects of fumonisin B1 and deoxynivalenol in rats

Raširenost bovericina u hrvatskom kukuruzu

The occurrence of beauvericin has been investigated in corn kernel (Zea mays L.) samples collected in 1996 (105 samples) and 1997 (104 samples) from 14 corn-producing counties of Croatia. Corn sample extracts were cleaned up by silica gel minicolumns and analyzed for beauvericin by high performance liquid chromatography with UV diode array detector. Higher incidence of positive samples was found in the 1996 crop as compared to the 1997 crop. In particular, 18 samples (17.4 %) of the 1996 crop were found contaminated with a mean beauvericin content of 393 ng/g and the highest level at 1864 ng/g. Only 1 out of 104 samples collected in the 1997 crop was contaminated with 696 ng/g of the toxin.n Beauvericin co-occurred with fumonisins B1 and B2 and with ochratoxin A in 17 and 4 samples, respectively. The results of mycological analysis of corn samples for beauvericin producing Fusarium species were in agreement with results of chemical analysis. In particular, higher incidence of Fusarium verticillioides (Sacc.) Nirenberg (known as Fusarium moniliforme Sheldon) (3.7 %) and Fusarium subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5.3 %) was found in 1996 with respect to 1997 (1.9 % of F. verticillioides and 0.4 % of F. subglutinans). This is the first report on the occurrence of beauvericin in Croatia.Učestalost bovericina analizirana je u uzorcima kukuruza skupljenim tijekom 1996. (105 uzoraka) i 1997. godine (104 uzorka) iz 14 županija Republike Hrvatske. Ekstrakt uzoraka kukuruza pročišćen je na silicij-gelskim minikolonama i analiziran na bovericin s tekućinskim kromatografom velike učinkovitosti (HPLC) s UV-diodnim detektorom. Učestalija pojava pozitivnih uzoraka nađena je godine 1996. u usporedbi s 1997. godinom. Godine 1996. nađeno je 18 uzoraka (17,4 %) kontaminiranih bovericinom sa srednjom vrijednošću pozitivnih uzoraka od 393 ng/g, odnosno s najvećom količinom od 1864 ng/g. Samo 1 od 104 skupljena uzorka godine 1997. bio je onečišćen s 696 ng/g toksina. Bovericin je nađen zajedno s fumonizinom B1 i B2 u 17 uzoraka, a s okratoksinom A samo u 4 uzorka. Mikološkom analizom utvrđene Fusarium vrste slažu se s kemijskim analizama na mikotoksine. Veća pojava Fusarium verticillioides (Sacc.) Nirenberg (poznat i kao Fusarium moniliforme Sheldon) (3,7 %) i F. subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5,3 %) nađena je godine 1996. u usporedbi s 1997. godinom kada je ustanovljeno (1,9 %) F. verticillioides i (0,4 %) F. subglutinans. Ovo je prvo izvješće o prisutnosti bovericina u Republici Hrvatskoj

Control of Penicillium expansum by an epiphytic basidiomycetous yeast

Postharvest biocontrol agents are considered a viable alternative to the use of synthetic chemicals as demonstrated by extensive research conducted by scientists and companies worldwide. In the present investigation, the biocontrol potential of a carotenoid-producing basidiomycetous yeast isolated from table grape flowers was analyzed. The strain RY1 proved to be Sporobolomyces roseus. In vitro and in vivo tests were conducted to assess its efficacy against Penicillium expansum, one of the most important postharvest pathogens and producer of the mycotoxin patulin. The yeast proved to control both fungal growth and patulin production, and, in addition, to greatly affect disease incidence and severity on apples. Its mode of action is presumably related both to the competition for nutrients and the production of antifungal volatiles. As such, although further large-scale trials are needed, our S. roseus strain represents a potential interesting biocontrol agent to be applied after harvest

Raširenost bovericina u hrvatskom kukuruzu

The occurrence of beauvericin has been investigated in corn kernel (Zea mays L.) samples collected in 1996 (105 samples) and 1997 (104 samples) from 14 corn-producing counties of Croatia. Corn sample extracts were cleaned up by silica gel minicolumns and analyzed for beauvericin by high performance liquid chromatography with UV diode array detector. Higher incidence of positive samples was found in the 1996 crop as compared to the 1997 crop. In particular, 18 samples (17.4 %) of the 1996 crop were found contaminated with a mean beauvericin content of 393 ng/g and the highest level at 1864 ng/g. Only 1 out of 104 samples collected in the 1997 crop was contaminated with 696 ng/g of the toxin.n Beauvericin co-occurred with fumonisins B1 and B2 and with ochratoxin A in 17 and 4 samples, respectively. The results of mycological analysis of corn samples for beauvericin producing Fusarium species were in agreement with results of chemical analysis. In particular, higher incidence of Fusarium verticillioides (Sacc.) Nirenberg (known as Fusarium moniliforme Sheldon) (3.7 %) and Fusarium subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5.3 %) was found in 1996 with respect to 1997 (1.9 % of F. verticillioides and 0.4 % of F. subglutinans). This is the first report on the occurrence of beauvericin in Croatia.Učestalost bovericina analizirana je u uzorcima kukuruza skupljenim tijekom 1996. (105 uzoraka) i 1997. godine (104 uzorka) iz 14 županija Republike Hrvatske. Ekstrakt uzoraka kukuruza pročišćen je na silicij-gelskim minikolonama i analiziran na bovericin s tekućinskim kromatografom velike učinkovitosti (HPLC) s UV-diodnim detektorom. Učestalija pojava pozitivnih uzoraka nađena je godine 1996. u usporedbi s 1997. godinom. Godine 1996. nađeno je 18 uzoraka (17,4 %) kontaminiranih bovericinom sa srednjom vrijednošću pozitivnih uzoraka od 393 ng/g, odnosno s najvećom količinom od 1864 ng/g. Samo 1 od 104 skupljena uzorka godine 1997. bio je onečišćen s 696 ng/g toksina. Bovericin je nađen zajedno s fumonizinom B1 i B2 u 17 uzoraka, a s okratoksinom A samo u 4 uzorka. Mikološkom analizom utvrđene Fusarium vrste slažu se s kemijskim analizama na mikotoksine. Veća pojava Fusarium verticillioides (Sacc.) Nirenberg (poznat i kao Fusarium moniliforme Sheldon) (3,7 %) i F. subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5,3 %) nađena je godine 1996. u usporedbi s 1997. godinom kada je ustanovljeno (1,9 %) F. verticillioides i (0,4 %) F. subglutinans. Ovo je prvo izvješće o prisutnosti bovericina u Republici Hrvatskoj

2-Butyl-5-pentyl­benzene-1,3-diol

In the title compound, C15H24O2, a natural dialkyl­resorcinol commonly named stemphol, the mol­ecules are linked into C(6) and C 2 2(4) chains and R 4 4(16) rings by inter­molecular O—H⋯O hydrogen bonds, creating mol­ecular sheets parallel to the (010) plane. The alkyl chains are directed orthogonally away from these planes in almost complete extension

Effects of temperature and incubation period on production of toxic metabolites by Alternaria radicina and A. alternata

The production of toxic metabolites by four isolates of &lt;i&gt;Alternaria radicina&lt;/i&gt; and two isolates of &lt;i&gt;A. alternata&lt;/i&gt; in rice grains and carrot discs at 1, 10 and 20&lt;sup&gt;°&lt;/sup&gt;C was investigated. Incubation lasted 21 and 35 days or 14 and 28 days for rice grains and carrot discs, respectively. Accumulation of toxins in inoculated carrot roots stored for 24 weeks and in inoculated dried carrots stored for 48 weeks was also determined. It was found that &lt;i&gt;A. radicina&lt;/i&gt; produced radicinin (RAD) and &lt;i&gt;epi&lt;/i&gt;-radicinol (&lt;i&gt;epi&lt;/i&gt;-ROH), whereas tenuazonic acid (TeA), altertoxin I (ATX I), alternariol (AOH) and alternariol methyl ether (AME) were produced by &lt;i&gt;A. alternata&lt;/i&gt;. Although the isolates tested were capable of producing toxins in rice grains at 1&lt;sup&gt;°&lt;/sup&gt;C, none of them was detected in carrot discs. Accumulation of &lt;i&gt;epi&lt;/i&gt;-ROH was observed in carrot roots stored for 24 weeks, whereas decreased amounts of RAD and &lt;i&gt;epi&lt;/i&gt;-ROH were observed in dried carrots stored for 48 weeks. No &lt;i&gt;A. alternata&lt;/i&gt; toxins were detected in stored carrot roots, whereas trace amounts of AOH were recorded in dried carrots after 32 and 48 weeks of storage.</jats:p