Occurrence of ochratoxin A in sweet wines produced in Spain and other countries.

A survey for the presence of ochratoxin A (OTA) was undertaken from 2001 to 2005 in 188 samples of sweet wines produced in Spain and in 102 samples originating from other countries: France (n = 49), Austria (9), Chile (9), Portugal (9), Greece (6), Italy (5), Germany (3), Hungary (2), Slovenia (2), Switzerland (2), Canada (1), Japan (1), New Zealand (1), Ukraine (1), South Africa (1) and the USA (1). The analytical method was based on immunoaffinity chromatography clean-up and high-performance liquid chromatography (HPLC) with fluorescence detection. The limit of detection (defined as a signal-noise ratio = 3) was estimated to be 0.01 microg l(-1). The limit of quantification (0.02 microg l(-1)) was checked as being the lowest measurable concentration. OTA was detected in 281 out of 290 samples analysed (96.9% positive) at concentrations ranging from 0.01 to 4.63 microg l(-1). The overall mean and median levels were estimated to be 0.50 and 0.14 microg l(-1), respectively. In Spanish sweet wines OTA was found in 99% of the samples, with mean and median values of 0.65 and 0.19 microg l(-1), respectively. The mean value obtained in this study for OTA in the Spanish sweet wines would result in an intake of about 37.5 and 3.2 ng day(-1) of OTA for regular consumers and for the overall population, respectively. These figures represent a minor contribution to the provisional tolerable weekly intake (PTWI) or TWI established by the Joint Expert Committee on Food Additives (JECFA) and the European Food Safety Authority: 3.8 and 3.1% for regular consumers; and 0.4 and 0.3% for the whole adult population, respectively.

Effects of pork vs veal consumption on serum lipids in healthy subjects.

AIMS: To analyse the influence of lean pork (P) and veal (V) consumption on the lipid profile of healthy subjects within the framework of a healthy diet comprising low levels of total fat (TF), saturated fatty acids (SFA) and cholesterol. DESIGN: Double-crossover, randomized and controlled trial SUBJECTS: 44 healthy individuals (22 male and 22 female), recruited voluntarily from the University Complutense of Madrid. The weight and lipid profiles of these volunteers were normal and their dietary patterns were typical for people in our area. INTERVENTIONS: The study comprised 4 phases: stabilisation phase (5 weeks), the participants followed their normal diet; second phase (6 weeks), half of the subjects, were randomised to lean pork or veal consumption, 150 g per day, for their main meal of the day; washout period (5 weeks) and final phase, which was the second phase of intervention (6 weeks). During the intervention stages, only the main meal of the day was taken in the Hospital. The rest of the subjects' diets consisted of different fortnightly menus designed in accordance with the recommendations of the Spanish Society of Arteriosclerosis (SEA). RESULTS: After both stages of intervention had been completed, there was a mean reduction of 5.5% in low-density lipoprotein cholesterol. However, after each intervention there were no significant differences between those who had consumed P, 2.62 (0.55) mmol/L and those who had consumed V, 2.71 (0.47) mmol/L. No differences were observed in any of the other parameters between those who had consumed P and those who had consumed V. CONCLUSIONS: Lean pork and veal produces similar effects on the lipid profiles of healthy subjects. Its consumption, as part of the saturated fat and cholesterol-controlled diet, could therefore be included in food guidelines, both for normal and therapeutic diets.

Effects of pork vs veal consumption on serum lipids in healthy subjects / Efecto del consumo de cerdo y de ternera sobre el perfil lipídico de sujetos sanos

AIMS: To analyse the influence of lean pork (P) and veal (V) consumption on the lipid profile of healthy subjects within the framework of a healthy diet comprising low levels of total fat (TF), saturated fatty acids (SFA) and cholesterol. DESIGN: Double-crossover, randomized and controlled trial SUBJECTS: 44 healthy individuals (22 male and 22 female), recruited voluntarily from the University Complutense of Madrid. The weight and lipid profiles of these volunteers were normal and their dietary patterns were typical for people in our area. INTERVENTIONS: The study comprised 4 phases: stabilisation phase (5 weeks), the participants followed their normal diet; second phase (6 weeks), half of the subjects, were randomised to lean pork or veal consumption, 150 g per day, for their main meal of the day; washout period (5 weeks) and final phase, which was the second phase of intervention (6 weeks). During the intervention stages, only the main meal of the day was taken in the Hospital. The rest of the subjects' diets consisted of different fortnightly menus designed in accordance with the recommendations of the Spanish Society of Arteriosclerosis (SEA). RESULTS: After both stages of intervention had been completed, there was a mean reduction of 5.5% in lowdensity lipoprotein cholesterol. However, after each intervention there were no significant differences between those who had consumed P, 2.62 (0.55) mmol/L and those who had consumed V, 2.71 (0.47) mmol/L. No differences were observed in any of the other parameters between those who had consumed P and those who had consumed V. CONCLUSIONS: Lean pork and veal produces similar effects on the lipid profiles of healthy subjects. Its consumption, as part of the saturated fat and cholesterolcontrolled diet, could therefore be included in food guidelines, both for normal and therapeutic diets (AU)

OBJETIVO: Analizar la influencia del consumo de carne magra de cerdo (P) y de ternera (V) en el perfil lipídico de sujetos sanos, cuando se realiza dentro de un patrón de dieta saludable con bajo contenido en grasa total (TF), ácidos grasos saturados (SFA) y en colesterol. DISEÑO: Ensayo cruzado doble, aleatorizado y controlado. SUJETOS: 44 sujetos sanos (22 varones y 22 mujeres), reclutados de forma voluntaria de la Universidad Complutense de Madrid. Los pesos y los perfiles lipídicos de estos voluntarios y su patrón de alimentación eran típicos de las personas de nuestra área. INTERVENCIONES: El estudio consta de 4 fases: fase de estabilización (5 semanas), los participantes seguían su dieta normal; segunda fase (6 semanas), la mitad de los sujetos se randomizaron para que consumieran carne magra de cerdo o de ternera, 150 g al día, durante la principal comida del día; periodo de lavado (5 semanas) y fase final, que era la segunda fase de intervención (6 semanas). Durante las fases de intervención, sólo la principal comida se realizaba en el hospital. El resto de las dietas de los sujetos estaba constituida por menús diferentes para 2 semanas que seguían las recomendaciones de la Sociedad Española de Arteriosclerosis (SEA). RESULTADOS: Tras ambas intervenciones, hubo una reducción media de un 5,5% en el LDL colesterol. Sin embargo, después de cada intervención no encontramos diferencias significativas entre los que consumieron P, 2.62 (0.55) mmol/L y estos que consumieron V, 2.71 (0.47) mmol/L. No se observó diferencias en el resto de los parámetros analizados entre los que consumieron P y los que consumieron V. CONCLUSIONES: El consumo de P y B produce efectos similares sobre el perfil lipídico de sujetos sanos. Su consumo, formando parte de dietas controladas en grasa saturada y colesterol, podrían incluirse en pautas alimentarias, tanto de dietas normales como terapéuticas (AU)

Determination of ochratoxin A in baby food by immunoaffinity column cleanup with liquid chromatography: interlaboratory study.

An interlaboratory study funded by the European Commission, Standards, Measurement and Testing Programme (4th Framework Programme) was performed to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatographic (LC) method for the determination of ochratoxin A in baby food at a possible future European regulatory limit (0.1 ng/g). The test portion is extracted in a blender with tert-butyl methyl ether (chosen to avoid use of chloroform but shown to give equivalent extraction efficiency) after addition of 0.5 mol/L phosphoric acid-2 mol/L sodium chloride solution. The extract is centrifuged and redissolved in a mixture of phosphate buffered saline solution and methanol. After removal of lypophilic substances with hexane, the extract is applied to an immunoaffinity column containing antibodies specific to ochratoxin A. The column is washed with water to remove the interfering compounds and the purified ochratoxin A is eluted with methanol. The separation and determination of ochratoxin A is performed by reversed-phase LC and detected by fluorescence after postcolumn derivatization (PCD) with ammonia. Test materials (baby food infant formulae), both spiked and naturally contaminated with ochratoxin A, were sent to 13 laboratories in 8 different European countries. Test portions were spiked at a level of 0.085 ng/g ochratoxin A. The average recovery for the spiked blank baby food was 108%. Based on results for spiked samples (blind pairs at 0.085 ng/g) as well as naturally contaminated samples (blind pairs at levels between 0.05 and 0.22 ng/g) the relative standard deviation for repeatability (RSDr) ranged from 18-36%. The relative standard deviation for reproducibility (RSDR) ranged from 29-63% and HORRAT values of between 0.4 and 0.9 were obtained.

Development of reference materials for paralytic shellfish poisoning toxins.

A project was undertaken to develop mussel reference materials that were certified for their mass fractions of saxitoxin and decarbamoyl-saxitoxin. Fifteen laboratories from various European countries participated. Three of these had major responsibility for substantial parts of the work and overall coordination of the project. The project involved 4 main activities: (1) procurement and characterization of calibrants; (2) improvement of analytical methodology; (3) preparation of reference materials, including homogeneity and stability studies; (4) 2 interlaboratory studies and a certification exercise. The joint activities resulted in 3 homogeneous and stable reference materials: 2 lyophilized mussel materials with and without naturally incurred paralytic shellfish poisoning (PSP) toxins, and a saxitoxin enrichment solution. The reference materials were certified with respect to their saxitoxin and decarbamoyl-saxitoxin content. The lyophilized mussel material with PSP toxins (CRM 542) contained <0.07 mg saxitoxin x 2HCl/kg and 1.59 +/- 0.20 mg decarbamoyl-saxitoxin x 2HCl/kg. The lyophilized mussel material without PSP toxins (CRM 543) contained <0.07 mg saxitoxin x 2HCl/kg and <0.04 mg decarbamoyl-saxitoxin x 2HCl/kg. The certified value of the saxitoxin mass fraction in the saxitoxin enrichment solution (CRM 663) was 9.8 +/- 1.2 microg/g.

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study.

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis.

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four post-column derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49 mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34 mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX-5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.

The effect of commercial processing on the paralytic shellfish poison (PSP) content of naturally-contaminated Acanthocardia tuberculatum L.

A study was undertaken to determine if any reduction in contamination of Acanthocardia tuberculatum L. (Mediterranean cockle) by paralytic shellfish poisons (PSP) could be enhanced by operations carried out during the industrial canning process, allowing contaminated raw material to be commercially marketed in safe conditions for edible purposes. A general decrease in PSP levels was consistently observed when comparing raw materials and their corresponding final products, these dropping to acceptable levels. PSP levels were determined by mouse bioassay and a fluorometric method, and saxitoxin was determined by HPLC. The detoxifying effects averaged over 71.7% and 81.8% (mouse bioassay), 70.6% and 90.9% (fluorometric method), 77.9% and 83.5% (HPLC), for boiling and sterilizing operations respectively. The highest level detected in raw material was 800 micrograms/100 g by mouse bioassay.

Occurrence of Aflatoxin and Aflatoxigenic Molds in Foods and Feed in Spain.

A survey was carried out to obtain data on the occurrence of aflatoxin and aflatoxigenic mold contamination of foods in Spain. A variety of commodities amounting to 338 samples were analyzed, comprising cereal grains, mixed feeds, edible nuts, wheat flour for bread-making, biscuits, sliced bread, soya beans and breakfast cereals. The results reveal a rather low incidence of aflatoxin contamination in samples tested. Aflatoxins were detected in 4 of 27 samples of mixed feeds at levels below 5 µg/kg; one sample of peanuts was contaminated with 120 µg aflatoxin B1/kg and 22 µg aflatoxin B2/kg. Aflatoxins B1 and B2 were also detected in a lot of whole maize flour, averaging 8 µg/kg and 3 µg/kg, respectively. Of a total of 288 samples tested, 100% showed variable incidences of fungal contamination. Maize samples were the ones most frequently contaminated with Aspergillus flavus (54.5%). Strains of A. flavus isolated from maize samples also showed the highest proportion of aflatoxigenic molds (17.2%) compared with those isolated from other sources.