A survey on distribution and toxigenicity of Aspergillus section Flavi in poultry feeds

Thirty-five samples of poultry feeds and corresponding raw materials (maize, soybean and meat meal) from a processing plant were analyzed to evaluate the distribution and toxigenicity of Aspergillus section Flavi isolates. Mycological analysis of the samples indicated the presence of five fungal genera (Aspergillus, Penicillium, Fusarium, Cladosporium, and Eurotium). Aspergillus flavus was the predominant species being present in 48.5% of the analyzed samples. Ninety-one isolates belonging to Aspergillus section Flavi were isolated; ninety were identified as A. flavus and only one as A. parasiticus. Fifty-seven isolates were capable of producing sclerotia, 41 were identified as L-type strains and 16 as type S. Fifty-seven percent of the isolates produced AFB₁ levels ranging from 0.05 μg/kg to 27.7 μg/kg whereas 86.8% produced CPA from 1.5 μg/kg to 137.8 μg/kg. L-strains produced from 0.05 to 14.8 μg/kg of aflatoxin and type S produced levels from 0.05 to 1.65 μg/kg. No significant differences in CPA production among S- and L-strains were observed. Sclerotial isolates produced AFB₁ levels ranging between 0.05 and 27.7 μg/kg and CPA levels from 3.8 to 47.3 μg/kg. More than half of the A. flavus isolates were able to produce AFB and CPA simultaneously. Twenty percent of the 35 samples were contaminated with aflatoxin B₁ whereas 34.3% were contaminated with CPA. The high rate of CPA producing isolates represents a potential risk of contamination with this toxin in poultry feeds.     

Detection of Aspergillus spp. and aflatoxin B1 in rice in India

Twelve hundred rice samples consisting of paddy (675) and milled rice (525) were collected from 20 states across India. These samples were assessed for Aspergillus spp. infection on selective medium and aflatoxin B₁ (AFB1) by indirect competitive ELISA. In this investigation, Aspergillus flavus contamination dominated in all the seed samples. The other major contaminants were Aspergillus niger, Aspergillus ochraceus and Aspergillus parasiticus. Out of 1200 rice samples, 67.8% showed AFB1 ranging from 0.1 to 308.0 μg/kg. All the paddy samples from Chattishgarh, Meghalaya and Tamil Nadu showed AFB1 contamination. Milled rice grains from different states showed below the permissible levels of AFB1 (average 0.5–3.5 μg/kg). Eighty-two percent of samples from open storage that were exposed to rain showed AFB1 contamination followed by one-year-old seed. Out of 1200 samples, 2% showed AFB1 contamination above the permissible limits (>30 μg/kg). This is the first comprehensive report of aflatoxin contamination in rice across 20 states in India.     

Composition,antimicrobial, antiradical and spasmolytic activity of Ferula heuffelii Griseb. ex Heuffel (Apiaceae) essential oil

The essential oil from underground parts of Ferula heuffelii from N.E. Serbia, was analysed using GC and GC–MS. The main compounds of the essential oil were elemicin (35.4%) and myristicin (20.6%). The essential oil exhibited the best antimicrobial activity against two strains of Candida albicans (MIC = 7.0 and 13.7 μg/ml), as well as against Micrococcus luteus (MIC = 13.7 μg/ml), Staphylococcus epidermidis (MIC = 17.6 μg/ml), Bacillus subtilis (MIC = 21.1 μg/ml) and Micrococcus flavus (MIC = 28.2 μg/ml). In the DPPH radical scavenging assay, essential oil showed substantial activity with SC₅₀ = 22.43 μl/ml. The essential oil was also tested for antispasmodic activity. It inhibited spontaneous contraction of isolated rat ileum dose-dependently, and at the concentration of 86.64 μg/ml exhibited 50% of the maximum effect of atropine. After incubation with 75.00 μg/ml of essential oil, acetylcholine did not induce contractions of ileum, and at 250.00 μg/ml, the essential oil almost completely abolished the spasmodic effect of potassium chloride (80 mM).     

Fumonisin level in corn-based food and feed from Linxian County,a high-risk area for esophageal cancer in china

The level of mycotoxin fumonisins in corn-based food and feed collected from Linxian County, a high-risk area for esophageal cancer in China, has been analyzed using high-performance liquid chromatographic coupled with evaporative laser scattering detector (HPLC-ELSD). A total of 104 corn kernel samples were obtained from local households, granaries, wholesale markets (central markets), and retail markets (stores and supermarkets). Fumonisin B₁ (FB₁) was detected in the samples from households, granaries, central markets, and stores, with a positive rate of 61.5%, 50%, 33.3%, and 17%, respectively. No fumonisin was detected in samples from the supermarket. The highest FB₁ levels (0.30–3.20 μg/g; mean, 1.42 μg/g) were found in samples from the granary, followed by household (0.25–1.80 μg/g; mean, 0.73 μg/g), central market (0.25–1.10 μg/g; mean, 0.51 μg/g), and store (0.22–0.34 μg/g; mean, 0.28 μg/g). Among the 80 corn kernel samples collected from local households, 18 of 24 (75.0%) moldy samples contained high levels of FB₁ (0.28–3.30 μg/g; mean, 1.58 μg/g), and 20 of 56 (35.7%) apparently healthy samples contained low levels of FB₁ (0.21–0.82 μg/g; mean, 0.46 μg/g). As the central market plays an important role in trade of corn-based food and feed in China, a total of 115 corn-based food and feed samples were collected from the local central market. The highest FB₁ levels (0.30–3.13 μg/g; mean, 1.50 μg/g) were found in feed, followed by unprocessed food (0.31–0.63 μg/g; mean, 0.47 μg/g) and processed food (0.21–0.28 μg/g; mean, 0.25 μg/g). The positive incidence of FB₁ in feed, unprocessed, and processed food were 53.6%, 33.3% and 17.9%, respectively. In conclusion, the results showed that corn-based food and feed from Linxian County contained low level of FB₁ (<2 μg/g) in general, but efforts should be made to control the fumonisin contamination in corn kernels stored in granaries and households.     

Determination of ochratoxin A in organic and non-organic cereals and cereal products from Spain and Portugal

The objective of this work was to know the occurrence of OTA in organic and non-organic cereals and cereal products from Spain and Portugal. A method based on extraction with matrix solid phase dispersion (MSPD) using octylsilica (C₈) followed by liquid chromatography coupled with fluorescence detection (LC–FD) was used to determine OTA from the selected samples. Recoveries of OTA from the studied samples spiked at 10 ng/g level ranged from 78% to 89% with a standard deviation of 3.66. The limits of detection and quantification of this method were 0.05 and 0.19 ng/g, respectively. Furthermore, LC–FD after OTA methylation was used to confirm the identity of OTA in all positive samples. This procedure was applied to 83 organic and non-organic samples including rice, wheat, barley, rye, oats and maize from Spain and Portugal. OTA was detected in 22% of the samples, with concentrations ranging from 0.20 to 27.10 ng/g. From the total OTA contaminated samples (n = 18), 72% were organic cereal and 28% were non-organic cereal samples, with mean concentrations of 1.64 and 0.05 ng/g, respectively. The 66% and 34% of contaminated samples were from Spain and Portugal, respectively, with mean concentrations of 0.93 and 0.64 ng/g for each country. Six contaminated samples exceeded the maximum limits (ML) for OTA fixed by European Commission Regulation (5 μg/kg), among them three were from Spain and three from Portugal.     

Comparison of dry matter losses and aflatoxin B1 contamination of paddy and brown rice stored naturally or after inoculation with Aspergillus flavus at different environmental conditions

The objective of this study was to compare the effect of different storage moisture conditions (0.70, 0.85, 0.90 and 0.95 water activity, a_w) and temperatures (20, 25, 30 °C) on (a) respiration rates (R) and dry matter loss (DML) of paddy and brown rice and (b) quantify aflatoxin B₁ (AFB₁) production by isolates of Aspergillus flavus from the rice samples and (c) inoculation of both rice types with A. flavus under these storage conditions on R, DML and AFB₁ contamination. There was an increase in temporal CO₂ production with wetter and warmer conditions in naturally contaminated rice. Higher R and consequently, % DML, were generally found in the brown rice (21%) while in paddy rice this was only up to 3.5% DML. From both rice types, 15 (83.3%) of 18 A. flavus isolates produced detectable levels of AFB₁ in a range 2.5–1979.6 μg/kg. There was an increase in DML in both rice types inoculated with A. flavus as temperature and a_w were increased. Interestingly very little AFB₁ was detected in paddy rice, but significant contamination occurred in the brown rice. The %DML in the control and A. flavus inoculated rice increased with temperature and a_w at both 25 and 30 °C from 1-2% to 15–20% DML at 30 °C and 0.95 a_w. All the inoculated rice samples had AFB₁ levels above the EU legislative limits for contamination in other temperate cereals and products derived from cereals (=2 μg/kg). Even samples with % DML as low as 0.2% had AFB₁ contamination levels twice the limits for other cereals. These results suggest that the mycotoxin contamination risk in staple commodities like rice, is influenced by whether the rice is processed or not, and that measurement of R rates can be used to predict the relative risk of AFB₁ contamination in such staple commodities.     

Analysis of mycotoxin fumonisins in corn products by high-performance liquid chromatography coupled with evaporative light scattering detection

Fumonisins are mycotoxins produced by the fungus Fusarium verticillioides, which is a widespread pathogen of corn. The mycotoxins are known to cause fatal diseases in some domestic animals and have been linked to human esophageal cancer in China and South Africa. Here, we describe a simple method for direct and quantitative analysis of the toxins in food products. The method is based on high-performance liquid chromatography coupled with an evaporative laser scattering detector (HPLC–ELSD) without any prior derivatization of the samples. Using this method, we have analyzed corn-based food samples from central markets in eastern China. The results showed that FB₁ was the main contaminant in the samples. The overall level of fumonisin contamination was relatively low, with a range of 0.25–1.80 μg/g (mean 0.74 μg/g) in 66.7% (16 of 24) of corn samples from Middle-eastern Area, 0.21–0.29 μg/g (mean 0.24 μg/g) in 28.6% (6 of 21) of corn samples from Northeastern Area, and 0.30–3.13 μg/g (mean 0.47 μg/g) in 30.0% (6 of 20) of corn samples from Southeastern Area.     

Detection and characterization of Listeria monocytogenes in Sao Jorge (Portugal) cheese production

Listeria monocytogenes is a foodborne pathogen that can cause serious invasive disease in humans. Because human listeriosis cases have previously been linked to consumption of contaminated cheese, control of this pathogen throughout the cheese production chain is of particular concern. To understand the potential for L. monocytogenes transmission via São Jorge cheese, a Portuguese artisanal cheese variety that bears a Protected Denomination of Origin classification, 357 raw milk, curd, natural whey starter, and cheese samples representative of the production chain of this cheese were collected over one year and tested for the presence of L. monocytogenes and selected physicochemical parameters. Although neither L. monocytogenes nor other Listeria spp. were detected in whey, curd, or cheese samples, 2 of the 105 raw milk samples analyzed were positive for L. monocytogenes. These 2 raw milk isolates represented a ribotype that has previously been linked to multiple human listeriosis outbreaks and cases elsewhere, indicating the potential of these isolates to cause human listeriosis. On average, physicochemical parameters of São Jorge cheese ripened for 4 mo presented values that likely minimize the risk of L. monocytogenes outgrowth during ripening and storage (mean pH = 5.48; mean moisture = 37.79%; mean NaCl concentration = 4.73%). However, some cheese samples evaluated in this study were characterized by physicochemical parameters that may allow growth and survival of L. monocytogenes. Even though our results indicate that raw milk used for São Jorge cheese manufacture as well as finished products is rarely contaminated with L. monocytogenes, continued efforts to control the presence of this pathogen in the São Jorge cheese production chain are urged and are critical to ensure the safety of this product.     

Rhus verniciflua Stokes flavonoid extracts have anti-oxidant,anti-microbial and α-glucosidase inhibitory effect

We isolated four compounds, fustin, gallic acid, 3′,4′,7-trihydroxyflavone, and fisetin from Rhus verniciflua. These compounds showed electron donation ability (87–94%) that was stronger than butylated hydroxyanisole (52%). Gallic acid (OD₇₀₀ = 1.98) showed the highest reducing power, and the other isolated compounds (OD₇₀₀ = 0.66–1.31) showed stronger activity than α-tocopherol (OD₇₀₀ = 0.21). The ethyl-acetate fraction had the highest phenolic content (723 mg GAE/g), followed by the 80% ethanolic extract (597 mg GAE/g). For Gram-negative bacteria, fisetin had the most potent anti-bacterial activity (MIC = 8 μg/ml) against Escherichia coli. 3′,4′,7-Trihydroxyflavone (106%), the 80% ethanolic extract (101%), and ethyl-acetate (98%) had the most powerful α-glucosidase inhibitory effect at 50 μg/ml. R. verniciflua extracts have potential as functional food additives.     

Determination of aflatoxin levels in nuts and their products consumed in South Korea

A total of 85 nuts and their products marketed in South Korea were assessed for aflatoxins using a monitoring scheme consisting of enzyme-linked immunosorbent assay (ELISA) for rapid screening, high performance liquid chromatography (HPLC) for quantification and LC–mass spectrometry (MS) for confirmation. Thirty-one out of 85 samples gave ELISA readings above 0.06 and were screened as possible positive samples. Aflatoxin contents of possible positive samples were determined using HPLC with a detection limit of 0.08–1.25 μg/kg and a quantification limit of 0.15–2.50 μg/kg. Nine samples including 1 raw peanut, 4 roasted peanuts, 2 peanut butters, 1 pistachio and 1 seasoned assorted nut were contaminated with aflatoxins (10.6% of incidence), ranging in various levels up to 28.2 μg/kg. LC–MS analysis on contaminated samples revealed that peaks eluting at 4.4, 5.2, 9.1 and 11.9 min were confirmed as aflatoxin G₁, aflatoxin B₁, aflatoxin G₂ and aflatoxin B₂, respectively.     

Aflatoxins contamination in spices and processed spice products commercialized in Korea

A survey for total aflatoxins (aflatoxins B₁, B₂, G₁, and G₂) was conducted on 88 spices and processed spice products commercialized in Korea. The presence of aflatoxins was determined by high-performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. Total aflatoxins (AFs) are detected in 12 samples (13.6% of incidence) including seven red pepper powder, two red pepper pastes (Kochujang), two curry and one ginger product. The contamination levels are 0.08–4.45 μg/kg as aflatoxin B₁ and 0.08–4.66 μg/kg as AFs. The liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis on contaminated samples was conducted for the confirmation of detected aflatoxins. The 12 samples which showed aflatoxins by HPLC/FLD were confirmed as aflatoxins by LC–MS/MS.     

Sterigmatocystin presence in typical Latvian grains

Ninety five samples of different Latvian grains (wheat, buckwheat, barley, oats and rye) from the year 2006 and 120 samples from the year 2007 were analyzed for Aspergillus ssp. mycotoxin–sterigmatocystin (STC) content. 13.7% of the analyzed 2006 year samples were positive for STC with the concentration levels ranging from <0.7 to 83 μg/kg and 35% of the analyzed 2007 year samples were positive for STC with the concentration levels ranging from <1 to 47 μg/kg. A previously developed sensitive LC – Electrospray Positive Ionization – MS/MS method was applied for the analysis of STC in grains. Method includes sample extraction with acetonitrile/water solution, solid phase extraction (SPE) on Strata X SPE column, separation on reversed phase C₁₈ column and STC detection by LC–MS/MS.     

Carotenoid composition from the Brazilian tropical fruit camu–camu (Myrciaria dubia)

Camu–camu (Myrciaria dubia) is a small berry, native to the Amazon, known as a rich source of ascorbic acid. The carotenoid composition of this fruit was determined using high performance liquid chromatography-diode array detection on C₁₈ and C₃₀ columns. Fruits produced in two different regions of São Paulo State, Iguape and Mirandópolis, were analysed. All-trans-lutein was the major carotenoid in camu–camu fruits from both regions, ranging from 45% to 55% of the total carotenoid content (160.5 ± 93.1 μg/100 g for Iguape and 601.9 ± 75.6 μg/100 g for Mirandópolis fruits), followed by β-carotene, violaxanthin and luteoxanthin. The levels of lutein, β-carotene, violaxanthin, luteoxanthin and other minor carotenoids were significantly higher in the camu–camu produced in Mirandópolis region, most probably due to the higher temperature and light exposure found in this region, in comparison to those from Iguape. Maturation was also an important feature affecting batches from the same region.     

Deoxynivalenol and nivalenol in commercial wheat grain related to Fusarium head blight epidemics in southern Brazil

A three-year (2006-2008) survey on commercial wheat grain was conducted aimed at quantifying the intensity of Fusarium head blight epidemics related to kernel quality and levels of deoxynivalenol (DON) and nivalenol (NIV). Grain samples, obtained from 38 municipalities throughout the state of Rio Grande do Sul, Brazil, were assessed visually for Fusarium-damaged kernels (FDK) and chemically using liquid chromatography-mass spectrometry (LC-MS/MS). Overall FDK mean levels were 15.5%, not differing among the years. Co-contamination was predominant (59/66) across samples and overall mean levels of DON and NIV were 540 and 337 μg/kg, respectively. When the levels of both mycotoxins were added together (DON + NIV), a higher correlation with FDK was found (R = 0.36, P < 0.01), compared to single toxin data. For the first time, the presence of NIV in levels comparable to DON is reported from a multi-year regional epidemiological survey in the country which should be of concern to the small grains industry.     

Organic acids composition of Cydonia oblonga Miller leaf

Organic acid profiles of 36 Cydonia oblonga Miller leaf samples, from three different geographical origins of northern (Bragança and Carrazeda de Ansiães) and central Portugal (Covilhã), harvested in three collection months (June, August and October of 2006), were determined by HPLC/UV (214 nm). Quince leaves presented a common organic acid profile, composed of six constituents: oxalic, citric, malic, quinic, shikimic and fumaric acids. C. oblonga leaves total organic acid content varied from 1.6 to 25.8 g/kg dry matter (mean value of 10.5 g/kg dry matter). Quinic acid was the major compound (72.2%), followed by citric acid (13.6%).     

Antioxidant properties and chemical composition of technical Cashew Nut Shell Liquid (tCNSL)

The present study analysed the antioxidant activity of the technical Cashew Nut Shell Liquid (tCNSL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay and the xanthine oxidase assay, as well as in vivo evaluation by Saccharomycescerevisiae assay. Also, the chemical composition of tCNSL was determined by gas chromatography–mass spectrometry (GC–MS), revealing the presence of cardanols (40.26%), cardols (29.95%), phytosterol (10.68%), triacontanes (4.66%) and anacardic acid (1.79%). The DPPH-based assay results showed that tCNSL 1000 μg/ml reduced the radical level by 88.9%, and the scavenging of hydroxyl radicals in the xanthine oxidase assay indicated significant antioxidant activity (IC₅₀ = 702 μg/ml). In addition, tCNSL exerts an important protective effect against oxidative stress in yeast when used in 100–500 μg/ml concentration range, when exposed to paraquat or H₂O₂, indicating an in vivo antioxidant effect.     

Rosmarinic acid,scutellarein 4′-methyl ether 7-O-glucuronide and (16S)-coleon E are the main compounds responsible for the antiacetylcholinesterase and antioxidant activity in herbal tea of Plectranthus barbatus (“falso boldo”)

Plectranthus barbatus, known as “falso boldo” in Brazil, is used in herbal tea or cooked as a vegetable. Infusions and decoctions of leaves from P. barbatus were analysed for their inhibition of acetylcholinesterase and their antioxidant activity. The decoction showed high inhibition activity (31% inhibition with 0.5 mg of extract/ml) and also high antioxidant activity (IC₅₀ = 45.8 ± 0.5 μg of dry extract/ml in the DPPH test; IC₅₀ = 69.8 ± 3.1 μg of dry extract/ml in the β-carotene–linoleic acid test). Rosmarinic acid, scutellarein 4′-methyl ether 7-O-glucuronide and (16S)-coleon E were the main constituents identified. These compounds have antiacetylcholinesterase activity. Rosmarinic acid and the scutellarein derivative have IC₅₀ = 440 μg/ml and 1 mg/ml, respectively. One milligram per millilitre of (16S)-coleon E showed 61% inhibition of the enzyme. Other Plectranthus species, P. ecklonii, P. fructicosus, P. lanuginosus and P. verticillatus, were also analysed and the results obtained correlated with the content in rosmarinic acid.     

Quantification of coumarin derivatives in Noni (Morinda citrifolia) and their contribution of quenching effect on reactive oxygen species

The quantification of coumarin derivatives such as scopoletin, 7-hydroxycoumarin (7-HC) and 4-hydroxycoumarin (4-HC) in Noni (Morinda citrifolia) was described. The coumarin derivatives were determined by HPLC-UV or -fluorescence detection. More than 95% of peak purity for coumarin derivatives in Noni sample was confirmed by a multi-wavelength fluorescence detector. Amounts of scopoletin and 7-HC in Noni juices (A–H) were ranging 5.1–231 μg/ml and 0.04–0.45 μg/ml, respectively (n = 12). No 4-HC was detected in any Noni samples examined.     

Antioxidant activity and phenolic content of 16 raisin grape (Vitis vinifera L.) cultivars and selections

Six raisin grape cultivars and 10 new raisin grape selections were analyzed for antioxidant activity (ABTS assay) and for total and individual phenolic compounds. Samples were freeze–dried and values are reported on a dry weight basis. Antioxidant activity across the 16 samples ranged from 7.7 to 60.9 μmol Trolox/g DW, with A95-27 exhibiting the greatest activity. Total phenolic content, determined in gallic acid equivalents using the Folin–Ciocalteau assay, ranged from 316.3 to 1141.3 mg gallic acid/100 g DW and was strongly correlated (r = 0.990) with antioxidant results. Concentrations of individual phenolics were determined by HPLC. trans-Caftaric acid was the predominant compound in all samples. A95-15 contained the lowest concentration (153.5 μg/g DW) of caftaric acid, while Fiesta contained the highest concentration (598.7 μg/g DW). Selections A56-66, A95-15, and A95-27 had much higher levels of catechin (86.5–209.1 μg/g DW) and epicatechin (126.5–365.7 μg/g DW) than the other samples.     

Determination of stilbenes in Sicilian pistachio by high-performance liquid chromatographic diode array (HPLC-DAD/FLD) and evaluation of eventually mycotoxin contamination

In this work, we have investigated about the presence of several natural stilbenes in 12 samples of pistachios harvested from 10 different farms of Sicily (Bronte and Agrigento). At the same time, we have evaluated the relation between the stilbenes synthesis and the possible contamination of mycotoxin produced by Aspergillus flavus and Aspergillus parasiticus. We have found two types of stilbenes in the samples of pistachios examined: trans-resveratrol and trans-resveratrol-3-O-β-glucoside (trans-piceid). Their concentration ranged from 0.07 to 0.18 mg/kg (av. = 0.12 ± 0.03 mg/kg) for trans-resveratrol, from 6.20 to 8.15 mg/kg (av. = 6.97 ± 0.55 mg/kg) for trans-piceid and from 6.38 to 8.27 mg/kg (av. = 7.09 ± 0.54 mg/kg) for total resveratrol.