Patulin content in apple products marketed in Northeast China

Patulin is a secondary metabolite, which is mainly produced by certain species of Aspergillus and Penicillium fungi. In this study, a total of 95 samples of apple products were analyzed for patulin content, including apple juice, baby food, apple juice concentrate, and mixed juice. Results of the study showed in 16% of apple products level of patulin found was higher than 50 μg/kg. Only 12 samples, 12.6% in 95 samples were below detectable limit for patulin analysis. The average and median content of patulin in all the samples was 20.4 and 10.3 μg/kg, respectively. The results of this study indicate that it is possible to reduce patulin levels in apple juice concentrate, the total reduction rate was 46.2% after processing. And the most significant stage for the reduction of patulin content was washing. After washing, the mean loss of patulin was 33.6%.     

Effect of processing of apple puree on patulin content

Mycotoxin patulin represents potential health hazard especially in apple based baby food. There are already a lot of data to predict the fate of the toxin during the processing of fruits, but not enough for the apple puree and the existing data for apple puree are not usually consistent. The objective of the study was to evaluate the course of patulin degradation during the processing of apple puree under the conditions close to the real production process. The apple samples were spiked with patulin at four levels of concentration (539 μg/kg, 140 μg/kg, 23 μg/kg and <2 μg/kg). The patulin content changes during the processing were followed. The samples were taken after the homogenization, pulping, pasteurization and aseptic packaging. All operations of apple puree production contributed to patulin reduction. The principle operation was pulping, where the patulin levels were reduced from 29% to 80% of original content.     

Incidence and level of patulin contamination in pure and mixed apple juices marketed in Italy

A survey on the occurrence of patulin was conducted during 2005 on commercial pure apple juices (53 samples) and mixed apple juices (82 samples) marketed in Italy. The current study was undertaken to investigate the possible influence of the agro-food production process employed (conventional or organic), of the fruit percentage in the commercial product (higher or lower than 50%) and of the type of apple juice (clear or cloudy) on the occurrence and level of patulin contamination. Patulin could be quantified in 34.8% of the samples ranging from 1.58 to 55.41 μg kg⁻¹. With the exception of one sample, the level of patulin was lower than 50 μg kg⁻¹, the maximum permitted threshold in fruit juices according to the European legislation. Mean levels of patulin were significantly lower in mixed apple juices (4.54 μg kg⁻¹) than in pure apple juices (9.32 μg kg⁻¹). Levels of patulin contamination were comparable in clear and cloudy juices. A similar incidence of positive samples was found in conventional and organic apple based juices, and the magnitude between the mean contamination levels, although higher in organic (10.92 μg kg⁻¹) than in conventional juices (4.77 μg kg⁻¹), was not statistically significant (p = 0.771; Mann–Whitney test). The magnitude between the means of patulin contamination in juices containing more than 50% fruit (11.26 μg kg⁻¹) and in juices with 50% or less fruit (3.35 μg kg⁻¹) was statistically significant (p = 0.016; Mann–Whitney test).     

Single-laboratory validation of a liquid chromatography method for the determination of patulin in apple juice

A method for patulin determination in apple juice was optimized and single-laboratory validated. Patulin was extracted with ethyl acetate and the extracts were cleaned-up in a column prepared in the laboratory. The determination was carried out by liquid chromatograph with a C₁₈ column and diode array detector. Linearity was observed from 25.4 to 532.5 μg/L. Mean recovery of 81.6% and relative standard deviations <5.7% were obtained for samples spiked with 27, 58 and 122 μg/L. Limits of quantification and detection were 10 and 4 μg/L, respectively. In the ruggedness experiment, seven factors were considered. The method presented the advantages of easiness, economical aspects, patulin identity confirmation and use of non-toxic solvents and reagents.     

Changes in the concentration of aflatoxin M1 during manufacture and storage of White Pickled cheese

In this study White Pickled cheese was produced from cow’s milk contaminated artificially with aflatoxin M₁ (AFM1) at two different levels, 1.5 and 3.5 μg/kg (ppb), and the effects of process stages on the AFM1 contents were investigated. Pasteurization at 72 °C for 2 min caused losses of AFM1 about 12% and 9%, respectively, in milk contaminated with 1.5 μg/kg AFM1, and 3.5 μg/l AFM1. These losses were found to be statistically significant (P < 0.01). After the cheese production, about 56% and 59% of total AFM1 remained in cheese–curd while about 32% of total AFM1 transferred to the whey for both 1.5 μg/kg and 3.5 μg/kg AFM1 contaminated milk. After 3-month storage in brine, AFM1 content of cheeses produced from 1.5 and 3.5 μg/kg AFM1 contaminated milks decreased by 2.9% and 2.8%, respectively. Changes in AFM1 content of cheese samples were found statistically insignificant (P > 0.05 and P > 0.01) for 3-month storage periods.     

Incidence of zearalenone and fumonisins in Bulgarian cereal production

Ninty-one small-grain cereals (wheat, barley, maize) collected during the 2007 harvest in Bulgaria were tested for zearalenone (ZON) and fumonisins contamination. Analytical methods based on immunoaffinity clean-up and detection by liquid chromatography was used after validation. Limits of detection for ZON in different matrices were below 4.0 μg/kg in barley and wheat, and slightly higher for maize (17.6 μg/kg). The limit of quantification for ZON was 12 μg/kg in barley and wheat, and 58.8 μg/kg in maize. Recovery values ranged between 84% and 105%. The occurrence of ZON in cereals were rather low and only single incidences was found – up to 148 μg/kg for maize and 36.6 μg/kg for other cereals. Fumonisins in maize have showed a widespread distribution (in 94.7% of tested samples). One of the tested samples was contaminated above the established maximum limits for unprocessed maize.     

Aflatoxin M1 contamination in dairy products marketed in Iran during winter and summer

In the present study, 298 dairy product samples consisting of pasteurized milk (91 samples), yoghurt (68 samples), white cheese (72 samples), butter (31 samples) and ice cream (36 samples) collected from popular markets in four large Iranian cities were examined for aflatoxin M₁ (AFM₁) by thin layer chromatography (TLC) technique. The toxin was detected in 66 (72.5%) pasteurized milk samples (mean: 0.052 μg/l; range: 0.013–0.250 μg/l), 45 (66.1%) yoghurt samples (mean: 0.032 μg/kg; range: 0.015–0.119 μg/kg), 59 (81.9%) white cheese samples (mean: 0.297 μg/kg; range: 0.030–1.200 μg/kg), 8 (25.8%) butter samples (mean: 0.005 μg/kg; range: 0.013–0.026 μg/kg) and 25 (69.4%) ice cream samples (mean: 0.041 μg/kg; range: 0.015–0.132 μg/kg). The concentration of AFM₁ in 36.2%, 20.6%, 30.5%, 9.6% and 27.7% of pasteurized milk, yoghurt, white cheese, butter and ice cream samples, respectively, were higher than Iranian national standard limits. Levels of AFM₁ in samples of pasteurized milk, yoghurt, butter and ice cream collected in winter were significantly higher (P < 0.05) than those collected in summer. In the case of white cheese, level of AFM₁ was higher in winter than in summer, but the difference was not statistically significant (P > 0.05). The results indicated that the contamination of the dairy products in such a level could be a serious public health problem at the moment.     

Patulin assessment and fungi identification in organic and conventional fruits and derived products

In this study, patulin levels in apples and tomatoes obtained in conventional and organic farms with 0 and 100% of rotten area, were determined by gas chromatography–mass spectrometry (GC–MS) to assess the influence of the production system with patulin content. Additionally, mould species were isolated and identified using classic morphological techniques and a DNA barcode system based on nrITS, β-tubulin and calmodulin genes. The most frequently isolated genera were Rhizopus, Mucor, Alternaria, Cladosporium, Botrytis, Aspergillus and Penicillium. Higher patulin levels were found in samples contaminated by Penicillium expansum. Patulin levels were not significantly different in samples obtained from the two production system (conventional and organic). Among the three studied apple varieties, Golden delicious was the most contaminated with patulin followed by Reineta. Fuji apples with 0 and 100% of rotten area did not present quantifiable patulin levels. A survey for first time realized in commercialized tomato products showed that 35.7% of the samples (10 of 28) contained patulin in levels ranging from 3.22 to 47.72 μg/kg. In apple juices, patulin levels ranged from 1.86 to 45.47 μg/kg, which is below the maximum legal requirement (50 μg/kg).     

Solid-phase extraction and HPLC determination of patulin in apple juice concentrate

Solid-phase extraction (SPE) pretreatment method was used to determine the patulin in apple juice concentrate. Undiluted apple juice concentrate was treated by C₁₈-SPE cartridge and analyzed by high-performance liquid chromatography (HPLC) using UV detector. The recovery rates and the coefficient variations were 96.4–114.1% and 1.62–4.82%, the minimum detectable level is 0.005 mg/kg. The method is fast, easy, reliable, and inexpensive; it is applicable to the analysis and control patulin in the course of apple juice concentrate processing and its commercial products.     

Deoxynivalenol reduction during the frying process of turnover pie covers

The effect of the frying process on deoxynivalenol contamination was evaluated. Deoxynivalenol naturally contaminated flour (1200 μg/kg) and fortified flour artificially contaminated (260 μg/kg) were used to prepare turnover pie dough covers. Frying was performed at three temperatures (169 °C, 205 °C and 243 °C) for different times. The final time for cooking at every temperature was established by measuring the colour during the frying process. Deoxynivalenol reduction was greater in the artificially contaminated samples (>66% at 169 °C, 43% at 205 °C and 38% at 243 °C). For the level of 1200 μg/kg, the average percentage of deoxynivalenol reduction, based on medians, was 28% when the dough covers were fried at 169 °C, 21% at 205 °C and 20% at 243 °C.     

Application of pulsed light to patulin reduction in McIlvaine buffer and apple products

Numerous studies around the world have reported the occurrence of patulin in commercialized apple products. The persistence of this mycotoxin in apple products indicates that current methods used to reduce it during the manufacturing process are not entirely successful and reflects the need to evaluate new detoxification methods. The purpose of the present study was to investigate the effect of pulsed light (PL) dose on patulin degradation in McIlvaine buffer, apple juice and apple purée. The exposure of all samples to PL doses between 2.4 and 35.8 J/cm² resulted in a significant decrease in patulin levels. Patulin reduction in McIlvaine buffer did not depend markedly on the initial concentration of the mycotoxin. At the maximum dose tested, the remaining average patulin level dissolved in McIlvaine buffer was approximately 5–15%, while in apple juice the values declined up to 22%. In apple purée naturally contaminated with 29 μg/kg of patulin, exposure to a PL dose of 12 J/cm² provoked a 51% reduction in patulin concentration, while no residual contamination was detected for higher irradiation times.These results suggested that PL treatment would be a potential alternative method to reduce patulin contamination in apple products. However, further investigations need to be conducted to evaluate toxicological safety of patulin degradation product(s).     

High contents of cadmium,lead, zinc and copper in popular fishery products sold in Turkish supermarkets

Selected toxic (cadmium, lead) and essential (zinc and copper) trace metals were determined by means of differential pulse stripping anodic voltammetry (DPSAV) in some different brands and kinds of fishery products purchased from the popular supermarkets of Turkey. Among the fishery products, the highest concentration of cadmium, lead, zinc and copper were found in the frozen anchovy (494.2 μg/kg, 314.2 μg/kg, 566 mg/kg, 45.7 mg/kg, respectively). While the canned anchovy fillet had the lowest cadmium (25.1 μg/kg), zinc (33.8 mg/kg) and copper (7.1 mg/kg) concentrations, canned tuna fish (Brand A) had the lowest lead (76.1 μg/kg). The concentrations of all toxic and essential elements in the selected products were high and often exceeded legal limits set by health authorities. Therefore these products must be monitored more often.     

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.     

A sensitive and validated method for determination of melamine residue in liquid milk by reversed phase high-performance liquid chromatography with solid-phase extraction

A sensitive and validated method for the determination of melamine residue in liquid milk is developed using reversed phase high-performance liquid chromatography-diode array detection (RP-HPLC-DAD) with solid-phase extraction (SPE). The conditions of the extraction, SPE and HPLC were investigated and optimized. The linearity is satisfactory in the range of 0.1–50 μg/mL with a correlation coefficient of 0.9998. Under the optimal conditions, the method limit of detection (LOD) and method limit of quantification (LOQ) were 18 μg/kg and 60 μg/kg, respectively. The recovery of melamine for milk samples spiked with 0.10–3 mg/kg was in the range of 85.5–99.3% with the RSDs (n = 3) of 2.3–3.7%. The intra-day assay precision (RSD) was 5.6% for five replicates of quality control milk sample at 2 mg/kg level. Confirmation of the identities of melamine was achieved by monitoring the two transitions in multiple-reaction monitoring (MRM) mode, and has been applied successfully for the determination of melamine residue in liquid milk samples. The confirmatory method can permit the detection of melamine residues at levels as low as 60 μg/kg in different liquid milks.     

Pressurized liquid extraction coupled to liquid chromatography for the analysis of ochratoxin A in breakfast and infants cereals from Morocco

A sensitive and reliable method using pressurized liquid extraction (PLE) and liquid chromatography (LC) has been developed for the analysis of ochratoxin A (OTA) in breakfast and infants cereals. Influence of several extraction solvents that affect PLE efficiency was studied. The selected PLE operating method was: 10 g of sample was packed into 22 ml stainless-steel cell and OTA was extracted with acetonitrile/water (80:20) at 40 °C, 34 atm in one cycle of 5 min at 60% flush. The mean recovery of OTA was 82 ± 4 at fortification level of 3 ng/g OTA. The limit of quantification (LOQ) of OTA was 0.25 ng/g. The proposed method was successfully applied to the analysis of 68 samples of breakfast and infants cereals products collected from different supermarkets and pharmacies in Rabat. Results showed that all analyzed infant cereals were free of OTA contamination. However, four samples of breakfast cereals were contaminated with OTA. Levels of OTA in positive samples ranged between 5.1 and 224.6 ng/g. All positive samples (5.8% of total samples) were above the maximum level set by EU regulations for OTA in cereal derivatives products.     

Natural occurrence of mycotoxins in cereals and spices commercialized in Morocco

Sixty samples of cereals (20 of corn, 20 of barley, and 20 of wheat) and 55 samples of spices (14 of paprika, 12 of ginger, 14 of cumin, and 15 of pepper) purchased from popular markets of Rabat and Salé in Morocco were analyzed for mycotoxins.Cereals samples were all analyzed for ochratoxin A (OTA). The average levels of contamination were 1.08, 0.42, and 0.17 μg/kg for corn, wheat, and barley, respectively. Samples of corn were also analyzed for zearalenone (ZEA) and fumonisin B₁ (FB₁) the average contaminations were 14 and 1930 μg/kg, respectively. Co-occurrence of OTA, FB₁, and ZEA was also checked. Spices samples were analyzed only for aflatoxins (AFs) and the average contaminations found for aflatoxin B₁ (AFB₁) were 0.09, 0.63, 2.88 and 0.03 μg/kg for black pepper, ginger, red paprika and cumin, respectively. The higher level of contamination was found in red paprika (9.68 μg/kg).The present report is the first one ever drafted on the natural co-occurrence of OTA, FB₁ and ZEA in cereals and on the occurrence of AFs in spices from Morocco.     

Occurrence of patulin in various fruit products and dietary exposure assessment for consumers in China

A quantitative method with broad applicability was developed and validated for patulin determination in fruit products by high-performance liquid chromatography (HPLC) with UV detection. Sample pretreatment was optimized for patulin extraction. 4.0 g of fruit products was extracted for patulin determination with acetonitrile and purified with a mixture of 1.0 g PSA and 3 g MgSO₄ plus a multifunctional cartridge to remove interferences. Under optimized conditions, the recoveries ranging from 75.6% to 118.5% were obtained at different spiking concentrations in various fruit products. The correlation coefficient of patulin from 5 to 1000 μg/L was approximately 1.00. The limits of detection (LODs) were from 2.6 to 7.5 μg/kg, and the limits of quantification (LOQs) were from 8.0 to 15.0 μg/kg for patulin in various fruit products. A total of 137 fruit products (97 dried fruits, 20 fruit juice and 20 jams) marketed and consumed in China were investigated. The incidence of patulin in fruit products was 30.7% (42/137) with a concentration ranging from 10.0 to 276.9 μg/kg. This study revealed that the dried figs, dried longans (seedless) and dried hawthorn products showed an average of patulin contamination of 87.6 μg/kg, 68.4 μg/kg and 5.1 μg/kg, respectively; the fruit juice of 5.4 μg/kg; the fruit jams of 5.0 μg/kg. The highest levels of patulin were found mostly in dried longans (seedless) and dried figs. Overall, 17.5% of total samples exceeded the maximum limit of 50 μg/kg set by the EU regulation. Chronic intake assessment indicated that only 0.29% (Hazard Quotient) acceptable daily intake (PMTDI, 0.4 μg/kg bw/day) was consumed through dried fruits, fruit juice and jams. Individual dietary risk assessment indicated patulin contamination in fruit products doesn't pose public health risks, but combined additive or synergistic toxic effects caused by multiple mycotoxin contaminations should not be ignored.     

Validation of the procedure for the determination of aflatoxin B1 in animal liver using immunoaffinity columns and liquid chromatography with postcolumn derivatisation and fluorescence detection

The validation of the procedure for the determination of aflatoxin B₁ in animal liver (pig, chicken, turkey, beef, calf) was performed. The limit of detection (LOD) and limit of quantification (LOQ) were 2 ng/kg and 7.8 ng/kg, respectively. The repeatability of measurements, represented by the standard deviation (RSD_r) was 7.5%, 7.1%, and 4.8% at the contamination levels of 0.025 μg/kg, 0.050 μg/kg, and 0.075 μg/kg, respectively. The relative standard deviation for the within-laboratory reproducibility (RSD_R) was 18% at the level of 0.025 μg/kg and 22% at the levels of 0.050 μg/kg and 0.075 μg/kg. The measurement uncertainties at the same contamination levels were ±0.007 μg/kg, ±0.016 μg/kg, and ±0.023 μg/kg, respectively. The mean recovery was 72.8%, the decision limit (CCα) 0.063 μg/kg and the detection capability (CCβ) 0.080 μg/kg. The results indicate that the procedure is suitable for the determination of aflatoxin B₁ in animal liver and can be implemented for the routine analysis.     

Occurrence of aflatoxin M1 in raw milk in South Korea using an immunoaffinity column and liquid chromatography

The level of aflatoxin M₁ (AFM₁) contamination in raw milk produced in South Korea was investigated using immunoaffinity column chromatography and high performance liquid chromatography with fluorescence detector. A total of 100 raw milk samples were collected from 100 cattle ranches located in three different provinces of South Korea. Forty eight out of 100 raw milk samples contained AFM₁ at low level (0.002–0.08 μg/L) with mean value of 0.026 μg/L. Among the AFM₁ contaminated samples, 29 raw milk samples contained only traceable amount of AFM₁ below the limit of LOQ, 0.02 μg/L. None of samples exceeded the maximum level (0.5 μg/L) of Korean regulation for AFM₁ in milk. The limit of detection was 0.002 μg/L. The result of recovery test with 0.5 μg/L AFM₁ in raw milk sample was 96.3% (SD 3.6, n = 5). This is the first pioneering study to investigate the level of AFM₁ in raw milk used in dairy industries in South Korea.     

A study on the occurrence of aflatoxin M1 in Iranian Feta cheese

This study was undertaken to determine the presence and levels of aflatoxin M₁ (AFM₁) in cheeses produced by different plants in the province of Tehran. For this purpose, a total of 80 cheese samples analyzed, and thin layer chromatography (TLC) was used to determine the presence and levels of AFM₁.AFM₁ was found in 82.5% of 80 of the cheese samples examined. The range of contamination levels varied among different months. AFM₁ in May, August, November, February samples ranged from 0.17 to 1.30, 0.15 to 2.41, 0.16 to 1.11, and 0.19 to 2.05 μg/kg, respectively, while the mean values were 0.41, 0.35, 0.36, and 0.52 μg/kg, respectively.The highest mean concentration of aflatoxin M₁ (AFM₁) was registered in February samples (0.52 μg/kg). The lowest mean concentration of aflatoxin M₁ was registered in August samples (0.35 μg/kg).Statistical evaluation showed that there were not significant differences (P > 0.05) between the concentrations of AFM₁ of cheese samples taken in May and August with November and February. In other words, AFM₁ contents of cheese samples taken in November and August were not lower than cheese samples taken in May and February. Almost 60.6% of the contaminated samples exceeded the maximum acceptable levels (0.25 μg/kg) that accepted by some of the countries such as Turkey.It was therefore concluded that, high occurrence of AFM₁ in cheese samples were considered to be possible hazards for human health.