Effect of Hibiscus sabdariffa extract and Nigella sativa oil on the growth and aflatoxin B1 production of Aspergillus flavus and Aspergillus parasiticus strains

This study was undertaken to evaluate the inhibitory effect of Hibiscus sabdariffa calyx extract at concentrations of 5, 7.5, 10 and 12.5 g/100 ml and Nigella sativa oil at concentrations of 1, 2 and 3 ml/100 ml on the growth and aflatoxin B₁ production by Aspergillus parasiticus (CBS 921.7) and Aspergillus flavus (SQU 21) strains. The inhibition of aflatoxin B₁ production by the different concentrations of H. sabdariffa calyx ranged between 91.5-97.9% and 87.1-93.3% for A. flavus and A. parasiticus strains, respectively, whereas the inhibition by different concentrations of N. sativa oil ranged between 47.9 and 58.3% for A. flavus and 32-48% for A. parasiticus strains. The different concentrations of H. sabdariffa calyx and N. sativa oil had no significant effect on the growth of either Aspergillus species. Neither H. sabdariffa calyx nor N. sativa oil detoxified pure aqueous aflatoxin. Our results suggest that H. sabdariffa calyx and N. sativa oil extracted from seeds had metabolic effects on aflatoxin biosynthesis pathway of both Aspergillus species and can be used as an effective biocontrol and non-toxic biopreservatives in food industry against aflatoxin contamination.     

Mycoflora and absence of aflatoxin contamination of commercialized cassava chips in Benin, West Africa

Studies conducted in Benin, in which the main staple foods are maize, cassava, groundnuts and yams, showed high levels of aflatoxin residues in blood of the exposed population. The natural contamination with fungi and aflatoxins in cassava chips sold at markets in Benin, West Africa was investigated. A total of sixty samples were sampled from open markets in 11 districts of 3 agroecological zones and analyzed for the presence of mycoflora and aflatoxin B₁, B₂, G₁ and G₂. Fourteen genera of fungi were associated with marketed dried cassava chips. Within these, twenty- two isolates were identified to species level, whereas four were identified only to genus. The dominating fungal species isolated were Rhizopus oryzae, Nigrospora oryzae, Chrysonilia sitophila, Cladosporium resinae, Cladosporium herbarum, Apergillus niger and Aspergillus flavus. Fifty-four out of sixty samples were contaminated with A. flavus. The rate of occurrence in CFU/g of A. flavus fungi was lower than for all other fungal species together. Aflatoxin was not detected in any of the samples analyzed using HPLC with post-column photochemical derivatization and fluorescence detection. The limit of detection (LOD) was 0.1 μg/kg. Results from this study suggest cassava chips are unlikely to be a source of aflatoxin in Benin, and that other staples such as maize and groundnuts are more important in aflatoxin exposure. Therefore it can be speculated that staples like maize and groundnut are more important in aflatoxin exposure.     

Investigations on the essential oil of Lippia rugosa from Cameroon for its potential use as antifungal agent against Aspergillus flavus Link ex. Fries

Lippia rugosa essential oil was tested for its effectiveness against Aspergillus flavus on artificial growth media. The chemical composition of the oil was determined by gas chromatography–mass spectrometry (GC–MS). Geraniol (51.5%), nerol (18.6%) and geranial (10.4%) were the main components of Lippia oil. After 8 days of incubation on essential oil supplemented medium, mycelium growth of A. flavus was totally inhibited by 1000 mg l^?1 of L. rugosa essential oil. The effect of essential oil on aflatoxin B₁ synthesis was evaluated in SMKY broth. The medium supplemented with different essential oil concentrations, was inoculated with A. flavus mycelium and incubated at 25 °C. After 2, 4, 6 and 8 days, aflatoxin B₁ (AFB₁) was quantified in the supernatant using Enzyme Linked Immuno-Sorbent Assay (ELISA). Results showed that aflatoxin B₁ synthesis was inhibited by 1000 mg l^?1 of L. rugosa essential oil after 8 days of incubation. The effect of the EO on the H⁺-ATPase pumping membrane was also evaluated in the presence of several concentrations of oil (200–2000 mg l^?1) by monitoring glucose-induced acidification of the external medium. L. rugosa essential oil at the concentration of 2000 mg l^?1 completely inhibited the activity of this enzyme. These data suggest that the essential oil of L. rugosa is a fungicidal for A. flavus and its possible cellular target include the H⁺-ATPase.Results obtained in the present study indicate the possibility of exploiting Lippia rugosa essential oil in the fight against strains of A. flavus responsible for biodeterioration of stored foods products.     

Chemical composition and in vitro antimicrobial,antifungal and antioxidant properties of essential oils obtained from some herbs widely used in Portugal

The aim of this study was determine (i) the chemical composition (ii) the antimicrobial activity (antibacterial and antifungal) and (iii) the antioxidant activity by means of four different antioxidant tests (DDPH, FIC, FRAP and TBARS) of the EOs of three aromatic herbs, Coriander (Coriandrum sativum), celery (Apium graveolens) and bush-basil (Ocimum minimum) widely used in Portugal.There is a great variability of the compounds presented in the three tested essential oils. Bush-basil EO had the highest total phenolic content (794.9 mg GAE/L) while coriander EO had the lower total phenolic content (52.3 mg GAE/L). Since bush-basil had the highest TPC it was expected to present a very high antioxidant profile, which was verified in 3 of the 4 assays (DPPH inhibition of 95.9%; FRAP values of 2.7 mmol Trolox/L; TBARS inhibition of 87.2%); coriander, despite the low TPC showed the highest inhibition in the FIC assay (94.1%).The bush-basil EO showed the highest antimicrobial activity, with MIC ranging between 0.6 and 5 μL/mL against bacteria and 0.04–2.5 μL/mL against yeasts. Both celery and coriander EO had a very similar antimicrobial activity against all the tested strains. The antifungal activity was higher in the bush-basil EO against Mucor racemosus and Penicillium chrysogenum since it was the only EO that showed growth inhibition on all the tested concentrations. Alternaria alternata showed great resistance against all the tested essential oils.     

Combined analytical and microbiological tools to study the effect on Aspergillus flavus of cinnamon essential oil contained in food packaging

Cinnamon essential oil has been used for centuries to protect food from microbiological infection, and in the last ten years cinnamon essential oil is also incorporated into food packaging materials as antimicrobial agent. However, very little is known about the real effect that it has on the microorganism cells. This study combines analytical and microbiological tools to elucidate cell damage produced on Aspergillus flavus. First, antifungal activity of cinnamon essential oil was evaluated at 10³,10⁴, 10⁵ and 10⁶ CFU/mL. Minimal Inhibitory Concentration (MIC) and Minimal Fungicidal Concentration (MFC) were determined by macrodilution in direct contact with the mold. A strong activity was obtained, with a MIC of 0.05–0.1 mg/mL, and a MFC of 0.05–0.2 mg/mL, both ranges depending on the initial fungal suspensions.Polyethylene terephthalate films containing cinnamon essential oil were tested in vapor phase, without direct contact with the mold. Active PET started showing activity at 2% CIN EO load and produced total inhibition at 4% CIN EO. SEM and FTIR were used to study the cell damage on the mold exposed to the cinnamon essential oil. Evident damage and a strong decrease in sporulation were found by SEM, while biochemical changes in conidia could be suggested from the FTIR spectra analysis. Two deposition techniques were used to prepare the samples for FTIR. The results obtained are shown and discussed.     

Biological activities of Boswellia sacra extracts on the growth and aflatoxins secretion of two aflatoxigenic species of Aspergillus species

Aflatoxins are the most serious carcinogenic, hepatotoxic, teratogenic and mutagenic secondary metabolites which adversely affect human and animal health. This study was designed to evaluate the in vitro inhibitory effect of different concentrations of Boswellia sacra resin (2.5, 5, 7.5 and 10 g/100 ml), leaf extract (5, 7.5, 10, 12.5 and 15 ml/100 ml), and essential oil (1, 2, 3, and 4 ml/100 ml) on the growth and aflatoxins production by two species of Aspergilli, namely Aspergillus flavus (SQU21) and Aspergillus parasiticus (CBS921.7). Resin of B. sacra caused 57.9–92.1% inhibition of aflatoxin secretion by A. flavus and 43.6–95.7% for A. parasiticus. However, the mycelial dry weights were significantly increased by 20.9–52.7% for A. flavus, and 8.9–68.5% for A. parasiticus. The leaf extract of B. sacra apparently enhanced aflatoxins production by 20–50%, and mycelial dry weight by 25.5–29.1% for A. flavus and A. parasiticus. The essential oil of B. sacra at different concentrations similarly inhibited the fungal growth and aflatoxins production by 45.8–83.7% for A. flavus and 41.3–83.5% for A. parasiticus which indicates the antifungal activity of this oil. None of the B. sacra extracts detoxified pure aqueous aflatoxin B₁. We have concluded that B. sacra resin and essential oil possess biological activity against biochemical synthesis and metabolic pathway of aflatoxin production of the two Aspergillus species. Therefore, the resin and essential oil of B. sacra can be recommended as safe plant based bioreservatives to enhance shelf life of food and feed products with reference to adverse effect of physical and synthetic chemical preservatives and their antimicrobial and aflatoxins inhibition activity.     

Antioxidant and anti food-borne bacterial activities of extracts from leaf and different fruit parts of Myristica fragrans Houtt

The main products of Myristica fragrans are the dried seed (nutmeg) and aril (mace), which are used as spices or condiments to flavor foods. In this study, its leaf and different parts of fruit (pericarp, aril, seed-kernel and shell) were compared for their total phenolic content, antioxidant and anti food-borne bacterial capacities. The 80% methanol extracts of aril, seed-kernel and shell shared the highest total phenolic content with shell extract acted as the greatest primary antioxidant, by having the highest ferric reducing antioxidant power (FRAP) activity (EC₅₀ 9.7 ± 0.1 μg/mL), β-carotene-bleaching activity (EC₅₀ 21.5 ± 2.7 μg/mL) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity (EC₅₀ 160.9 ± 13.9 μg/mL), whereas the pericarp extract exhibited highest secondary antioxidant activity as a metal chelator (EC₅₀ 75.6 ± 14.4 μg/mL). Only the aril and seed-kernel extracts were found to inhibit the food-borne bacteria with the lowest minimum inhibition concentration of 50 μg/mL, against Staphylococcus aureus (ATCC12600) and Bacillus cereus (ATCC10876). Our findings suggest the possibility of using the aril and seed-kernel extracts as natural food preservative and other parts as a new source of natural antioxidant for food and pharmaceutical industries.     

Curcuma longa L. essential oil composition,antioxidant effect,and effect on Fusarium verticillioides and fumonisin production

Essential oils may be an alternative to the use of synthetic fungicides for the control of fungi involved in agricultural product deterioration. The aim of the present study was to evaluate the composition and antioxidant effect of turmeric essential oil and its antifungal and antimycotoxigenic action on Fusarium verticillioides (Sacc.) Nirenberg. The essential oil major components were α-turmerone (42.6%), β-turmerone (16.0%) and ar-turmerone (12.9%). The half-maximal inhibitory concentration (IC₅₀) for the radical scavenging capacities of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were 0.54 and 10.03 mg/ml, respectively, indicating good antioxidant activity. The application of 17.9 and 294.9 μg/ml of turmeric essential oil decreased the development of F. verticillioides by 56.0 and 79.3%, respectively, when compared with the fungal control. The scanning electron microscopy demonstrated that the oil decreased the thickness and the length of the microconidia. Ergosterol production significantly decreased (p < 0.05) in groups treated with the essential oil relative to the control, indicating an effect of the oil on fungal biomass. The production of B₁ and B₂ fumonisins was significantly inhibited (p < 0.05) in groups treated with the essential oil. The results suggest that turmeric essential oil has antioxidant, antifungal and antimycotoxigenic activities.     

Radiosensitization of Aspergillus niger and Penicillium chrysogenum using basil essential oil and ionizing radiation for food decontamination

Stored products may be contaminated by pathogenic fungi such as Fusarium, Aspergillus and Penicillum. Fumigation with plant essential oil (EO) and irradiation treatment are options to control spoilage organisms. Basil essential oil and irradiation were tested alone and in combination for their antifungal effects in rice. Minimum Inhibitory Concentration (MIC) of basil EO was found to be 0.1% (v/v) against Aspergillus niger and Penicillium chrysogenum after 48 h. Radiosensitization of A. niger and P. chrysogenum in presence of 1% or 2% (v/v) basil EO was evaluated in vitro and in situ. At 1 and 2% of basil EO, the in vitro D₁₀ value was 0.43 and 0.31 kGy respectively for A. niger and 0.44 and 0.34 kGy respectively for P. chrysogenum. In inoculated rice, D₁₀ values for controls (sample without EO) were 0.67 and 0.63 kGy for A. niger and P. chrysogenum respectively, and the values were decreased at higher EO concentrations. For A. niger, a 2% (v/wt) basil EO alone caused a 0.42 to 1.18 log reduction on days 1 and 14 respectively, whereas treatment with 2 kGy radiation alone caused a 2.18 log reduction. The combined treatments resulted in a 4.6 log reduction of A. niger after 14 days of storage. For P. chrysogenum, 2% basil EO alone caused a 0.76 and a 1.12 log reduction on days 1 and 14 respectively, whereas a 2 kGy radiation dose caused a 2.41 log reduction. The combined treatments resulted in a 5.0 log reduction of P. chrysogenum after 14 days of storage. The findings demonstrated the potential of basil EO as antifungal agent and its efficacy to increase the radiosensitivity of A. niger and P. chrysogenum during irradiation treatment.     

Variation of levels of aflatoxin M1 in raw milk from different localities in the central areas of Punjab, Pakistan

The occurrence of aflatoxin M₁ (AFM₁) in samples of raw milk of buffaloes and cows from different localities in the central areas of Punjab, the province of Pakistan, was determined by using high-performance liquid chromatography (HPLC) with prior clean-up step applying immunoaffinity columns. The present study has been designed to find out the variation of levels of aflatoxin M₁ in raw milk of different localities. Feed has major role for prevalence of aflatoxin M₁ in milk and different feed regimen is being used in different areas. Total 480 milk samples were analyzed, among these 360 were of buffalo milk and 120 were of cow milk. The percentage of AFM₁ contamination in buffalo milk and cow milk was 42.5% and 52.5%, respectively. The mean value of AFM₁ was 0.027 μg L⁻¹ in buffaloes’ milk and was 0.044 μg L⁻¹ in cows’ milk. In both types of milk, level of AFM₁ concentration was higher in milk samples obtained from urban and semi-urban areas and it was minimal in milk from rural areas.     

Efficacy of pulsed electric fields for the inactivation of indicator microorganisms and foodborne pathogens in liquids and raw chicken

This study investigated the ability of pulsed electric fields (PEF) to inactivate a range of microorganisms in liquid media and on raw chicken meat. The susceptibilities of ten Campylobacter isolates (seven Campylobacter jejuni isolates and three Campylobacter coli isolates), Escherichia coli (ATCC 25922) and Salmonella Enteritidis (ATCC 13076) to PEF in liquid media were investigated. All Campylobacter isolates tested in liquid were susceptible to PEF treatment (65 kV/cm, 5 μs, 500 Hz) with reductions of between 4.33 and 7.22 log₁₀ CFU/mL observed for the longest treatment (30 s). Significant differences in susceptibility were observed between Campylobacter isolates subjected to equivalent PEF treatments ranging from 2.41 to 5.19 log₁₀ CFU/mL. Campylobacter isolates processed in liquid media were found to be more sensitive to PEF than E. coli and S. Enteritidis (P < 0.05). The application of PEF (3.75 and 15 kV/cm, 10 μs, 5 Hz) to inoculated samples of raw chicken did not result in any significant reductions in total viable counts, Enterobacteriaceae, C. jejuni, E. coli or S. Enteritidis. Therefore, under the conditions used in this study, PEF technology may not be suitable as a food safety intervention measure for the control of microbial contaminants on broilers during processing although it may have potential to reduce contamination of process water (e.g. scald or spin chill water).     

Upland rice vinegar vapor inhibits spore germination,hyphal growth and aflatoxin formation in Aspergillus flavus on maize grains

The efficacy of vapor-phase (VP) upland rice vinegar (URV) was investigated as a bio-fumigant for maize, to reduce consumer health risks associated with spore and toxin formation by Aspergillus flavus. Complete reduction of mycelial growth occurred with in vitro VP exposure to URV (containing 0.0017 mmol/L acetic acid) or with VP exposure to pure acetic acid (PAA) (containing 0.0023 mmol/L acetic acid). No significant differences were observed between the two materials after 90 min exposures. Using gas chromatography-mass spectrometry (GC-MS), URV vapor was shown to contain volatiles having antifungal activities. These are identified as isoamylalcohol, 1-butanol, 3-methyl-, acetate and β-phenylethyl acetate. It is suggested these volatiles increase the antifungal effectiveness of URV. Exposure to VP-URV (containing 0.0043 mmol/L AA) for 5 h completely eliminated viable spores of A. flavus on maize seeds (23% moisture content) previously inoculated with 4.43 ± 0.28 log spores/g). At the same time, aflatoxin production decreased, as VP-URV exposure increased. Hence, VP-URV is shown to be an effective control agent for A. flavus mycelial growth and aflatoxin formation on maize, so effectively reducing the potential for consumer health risks due to this widespread fungus.     

Occurrence of aflatoxin M1 in white cheese samples from Tehran, Iran

This study was undertaken to determine the occurrence of aflatoxin M₁ (AFM₁) in 50 white cheese samples from 2 dairy factories in summer 2008 and winter 2009. Enzyme-linked immunosorbent assay (ELISA) method was used for analysis of the samples. Aflatoxin M₁ was found in 60% of the cheese samples, ranging from 40.9 to 374 ng/kg. Toxin levels in 6% of the samples exceeded the Iranian national standard limit i.e. 200 ng/kg. Considering seasonal variability, mean concentration of AFM₁ in the samples collected in winter was significantly (P < 0.03) higher than those collected in summer. Therefore, high occurrence of AFM₁ in cheese samples could be a potential hazard for public health.     

Influence of emulsifier type on the antifungal activity of cinnamon leaf,lemon and bergamot oil nanoemulsions against Aspergillus niger

Only exiguous data are currently available on the antifungal properties of essential oil (EO) nanoemulsions against spore-forming microorganisms. The aim of this work is to develop physically stable nanoemulsion-based delivery systems for different EOs (cinnamon leaf, lemon, and bergamot), to exploit their antifungal properties against Aspergillus niger. The inhibition of mycelial radial growth and spore germination were used as indicators of antifungal activity of the nanoemulsions, which were prepared at 3 wt% EO, using non-ionic Tween 80 (T80) or anionic whey protein isolate (WPI) (1 wt%) as emulsifiers, and sunflower oil (1 wt%) as ripening inhibitor. The nanoemulsions were physically stable over seven days of accelerated aging at 35 °C.The minimal inhibitory concentration of free cinnamon leaf and of both citrus EOs were 0.35 and 5.50 μg/g, respectively. The encapsulation of cinnamon leaf EO in nanoemulsions significantly enhanced the inhibiting effect against A. niger mycelial growth and spore germination, with respect to the free EO. In contrast, for citrus EOs, the encapsulation in nanoemulsions generally decreased the antifungal activity, likely because of the nanoemulsion acting as a hydrophobic sink for the main constituents of citrus EOs. The emulsifier played a fundamental role in the resulting antifungal activity, with WPI-based nanoemulsions being more effective in inhibiting the mycelial growth and the spore germination of A. niger than T80-based ones. The antifungal action was correlated to the morphological alterations observed in A. niger, such as the loss of cytoplasm in fungal hyphae and hyphal tip. The results of this study show the importance of nanoemulsions design in the development of efficient and stable natural antifungal agents for food applications.     

复合SiO2-WO3催化剂的制备、表征及氧化脱除苯并噻吩性能

 采用溶胶-凝胶法制备了SiO₂-WO₃催化剂,并采用XRD、FT-IR、BET、TG-DTA等方法对催化剂进行表征。以苯并噻吩(BT)为模型化合物,H₂O₂为氧化剂,考察了催化剂的活性元素、制备方法、n(W)/n(Si)和焙烧温度对其催化氧化脱硫活性的影响。结果表明,W的引入降低了SiO₂的比表面积,SiO₂-WO₃催化剂中W的主物相为WO₃。在以W为活性组元,且n(W)/n(Si)为0.1时,500℃焙烧得到的SiO₂-0.1WO₃催化剂具有最好的催化脱硫活性。在模拟油20 mL、催化剂SiO₂-0.1WO₃用量0.04 g、n(H₂O₂)/n(S)为15.9、乙腈/模拟油体积比0.3、65℃反应60 min的条件下,苯并噻吩模拟油脱硫率可达99.3%。     

Effect of water activity and temperature on the growth of Aspergillus flavus,the expression of aflatoxin biosynthetic genes and aflatoxin production in shelled peanuts

The contamination of peanuts with Aspergillus flavus and subsequent aflatoxins is considered to be one of the most serious safety problems in the world. Water activity (a_w) and temperature are limiting factors for fungal growth and aflatoxins production during storage. To optimize the practical storage parameter, the effect of a_w (0.85–0.99) and temperature (15–42 °C) on fungal growth, aflatoxin production and the expression of aflatoxin biosynthetic and regulatory genes in shelled peanuts was investigated. A. flavus grew at a lower rate when temperature ≤20 °C or a_w ≤ 0.85. For the growth of A. flavus in shelled peanuts, the optimum conditions were a_w was 0.98, and the optimum temperature was 37 °C. The maximum amount of AFB₁ in peanuts was obtained at 28 °C and a_w 0.96. Real-time analysis showed that 16 of 25 genes had highest expression levels at 28 °C under a_w 0.92, while 9 genes had highest expression levels at 37 °C under a_w 0.92. Compared with 37 °C, all aflatoxin biosynthetic pathway genes were down-regulated at 42 °C. All the pathway genes and laeA were up-expressed at a_w of 0.96 under 28 °C, compared to a_w 0.99. Furthermore, there was a good positive correlation between the ratio of aflS/aflR and AFB₁ production. The expression of laeA was also positively correlated with AFB₁ production while the expression of brlA was correlated with the A. flavus growth. The results of this study suggest that AFB₁ production in peanut kernels can occur over a wider range of a_w × temperatures levels compared to formula media and peanut media. Previous studies have showed that AFB₁ could not be produced on formula media at 37 °C without the expression of most aflatoxin structural genes. But, in the un-autoclaved shelled peanuts, high concentration of AFB₁ was produced at 37 °C with up-regulation of some aflatoxin biosynthetic genes. From a food safety point of view, the results can be used to optimize certain food technological processes and develop prevention strategies to control such carcinogenic natural metabolites in grains (such as peanuts, maize and rice) and derived products.     

Effect of seasonal variations and lactation times on aflatoxin M1 contamination in milk of different species from Punjab, Pakistan

During October 2009 to September 2010, aflatoxin M₁ (AFM₁) levels were analyzed by HPLC-FLD in 356 milk samples of different lactating species (buffalo, cow, goat, sheep and camel) from Punjab (Pakistan). Recoveries of AFM₁ ranged from 92 to 97% and the limit of detection (LOD) was 0.004 μg/L. For all lactating species the mean concentration of AFM₁ was significantly higher in winter season than in summer (p < 0.05). The results showed that 55, 56, 32, 58 and 27% of winter milk samples of buffalo, cow, goat, sheep and camel exceeded the EU maximum limit (0.05 μg/kg), compared with 38, 33, 21, 36 and 14% of summer milk samples, respectively. For all lactating species the mean concentration of AFM₁ was significantly higher in morning milks than in evening milks (p < 0.05). The percentage of morning milk samples exceeding the EU maximum limit was 72, 67, 69, 71 and 44% for buffalo, cow, goat, sheep and camel, while for evening milks percent non compliant rates were 39, 30, 18, 33 and 25%, respectively. The level of AFM₁ tended to be higher in animal species fed mainly on concentrate mixtures (buffalo and cow) than in other species grazing on fresh greens.     

Potential of Escherichia coli as a surrogate indicator for postchill broiler carcasses with high Campylobacter counts

Surrogating Campylobacter contamination level in broiler carcasses with other bacterial indicators, used to evaluate the hygienic status of the slaughterline operations, might be stimulation to the broiler meat industry to improve control of Campylobacter during slaughter. Theoretically, Escherichia coli might have some practical merits as a potential indicator for carcasses contaminated with Campylobacter. This study investigates the correlation between the counts of E. coli and Campylobacter in 231 postchill broiler carcasses. The impact of setting a process hygiene target based on E. coli counts on reducing the frequency of carcasses contaminated with Campylobacter at level of ≥3 log₁₀ CFU/g was also investigated. Almost half (48.9% (46/94)) of the carcasses with enumerable Campylobacter (≥1 log₁₀ CFU/g) had E. coli counts between 3 and 4 log₁₀ CFU/g. In addition, 54.8% (17/31) of the carcasses contaminated with Campylobacter of ≥3 log₁₀ CFU/g were correlated with E. coli count range of ≥3 & <4 log₁₀ CFU/g. A theoretical scenario assuming that hygiene and processing measures could allow achieving a target for E. coli that not exceeding 3 log₁₀ CFU/g showed a parallel impact on Campylobacter contamination in broiler carcasses. In such scenario, the overall number of Campylobacter-positive carcasses could be dropped from 40.6% to 12.5%; in addition, 80.6% (25/31) of the carcasses contaminated with Campylobacter of ≥3 log₁₀ CFU/g could be eliminated. Findings from this study reveal that a hygiene target based on E. coli count could be used as an indirect sanitary tool for reducing the level of Campylobacter contamination in postchill broiler carcasses.     

Aflatoxigenic fungi and aflatoxins occurrence in sultanas and dried figs commercialized in Brazil

The presence of aflatoxins, Aspergillus flavus and Aspergillus parasiticus in dried fruits was investigated. A total of 62 dried fruit samples were analyzed (24 black sultanas, 19 white sultanas and 19 dried figs). A total of 10 A. flavus isolates were found, nine in one white sultana sample (corresponding to 18% infection) and one isolate in dried figs (2%), and all of them were aflatoxin B₁ and B₂ producers. A. parasiticus was not found. Aflatoxins were detected in 3 of 19 (16%) white sultana samples analyzed and, the limits were not higher than 2.0 μg/kg. In dried figs 11 of 19 (58%) samples were contaminated with aflatoxins and, with exception of one sample that was contaminated with 1500 μg/kg of B₁ aflatoxin, the others had less than 2.0 μg/kg. Neither aflatoxigenic or aflatoxins contaminated black sultanas.     

Antioxidant activity of essential oil and aqueous extract of Pelargonium graveolens L’Her

Pelargonium graveolens L’Her is an aromatic, rose-scented herb which is indigenous to various parts of southern Africa, and nowadays cultivated worldwide. This work presents the first phytochemical investigation of P. graveolens cultivated in Bosnia. The volatile profile of odorous parts of the plant was analysed by GC/MS. More than eighty compounds were identified in essential oils obtained from the leaves and stems, representing 92.3% and 96.3% in total, respectively. The major compounds in essential oils were oxygenated monoterpenes (64.3-74.2%), with geraniol (27.5-50.2%) and citronellol (14.2-19.0%) as the main representatives. The content of phenolic compounds in corresponding hydrosols as 34.88 ± 2.00 mg GAE/g in leaves and 102.44 ± 1.63 mg GAE/g in stems including flavonoid compounds of 32.35 ± 0.81 mg GAE/g to 101.87 ± 1.03 mg GAE/g. The radical-scavenging activity was measured by the DPPH method and IC₅₀ values ranged from 0.19 ± 0.05 mg/mL (stems) to 0.39 ± 0.04 mg/mL (leaves) for hydrosols, and from 63.70 ± 1.56 mg/mL (leaves) to 64.88 ± 1.12 mg/mL (stems) for essential oils.