Quantification of aflatoxin M1 carry-over rate from feed to soft cheese.

From January to December 2016, samples of milk and feeds of dairy cattle were monthly collected. The concentration of mycotoxins in all matrices was determined using the enzymatic immunoassay technique. The average concentration of aflatoxin B1 (AFB1), deoxynivalenol (DON) and zearalenone (ZEA) in feed was 3.01, 218.5 and 467 ug/kg, respectively. The average AFB1 carry-over rate was 0.84% with a variation between 0.05 to 5.93%. Particle size of the feed (P = 0.030) and individual milk production (P = 0.001) affected this rate. Mini-soft cheeses were produced using milk naturally contaminated with aflatoxin M1 (AFM1) as raw material to study its distribution both in whey and in cheese. The average level of AFM1 in milk was 0.014 µg/l. None of milk samples exceeded the maximum level accepted for AFB1 by the Southern Common Market (MERCOSUR) legislation (0.5 µg/l) and only 5.5% of samples exceeded the European Union (UE) regulations (0.05 µg/l). After the cheese elaboration, the concentration of AFM1 was determined in whey and in cheese. The greatest proportion (60%) was detected in whey while 40% AFM1 remained in the cheese. However, the concentration of AFM1 was higher in the cheese compared to the original milk.

Mycoflora study in a wheat flour mill of Argentina

The mycoflora of the environment: wheat conditioning, milling and screening, and filling zone, as well as, raw material -wheat-, intermediate product -grits- and end product -flour- on day 1, and after cleaning improvements -days 45 and 90- were studied in an Argentine wheat mill. Samples were incubated at 28°C for 5-7 days on Malt Extract Agar with chloramphenicol (100 mg L-1) and the results were expressed in colony forming units per cubic meter of air (CFU m-3) or per gram of sample (CFU g-1), respectively. Fungal genera and species were isolated and identified and the potential toxicogenic capacity of the Aspergillus flavus and Fusarium graminearum isolated was studied. Time-Place and Time-Product multifactorial ANOVA were carried out. After cleaning improvements, CFU m-3 of air decreased as a function of time. Cladosporium and Alternaria were abundant in every zone, Aspergillus predominated in the wheat conditioning zone and Penicillium and Eurotium decreased with time. Wheat was more contaminated than grits and flour; Aspergillus, Eurotium and Mucoraceae family were the most abundant. Deoxynivalenol was above the levels allowed in wheat, being acceptable in grits and flour. Aflatoxin and Zearalenone showed acceptable levels. When studied in vitro, 53% of Aspergillus flavus and 100% of Fusarium graminearum isolates, produced Total Aflatoxins, and Deoxynivalenol and Zearalenone, respectively.

Exposure assessment of mycotoxins in cow's milk in Argentina.

A stochastic simulation model was developed to carry out the first quantitative risk exposure assessment of the mycotoxin level in cow's milk produced in Argentina. The prevalence and concentration of aflatoxin M1 (AFM1), deoxynivalenol (DON) and zearalenone (ZEA) were modeled at various stages through milk processes complying with Argentinean practices. Concentration of AFM1 (0.059ppb), DON (0.338ppb) and ZEA (0.125ppb) in dairy milk were estimated. The proportion of feed samples that exceeded the maximum level accepted by European regulations for AFB1, DON and ZEA were estimated at 25.07%, 0.0% and 8.9%, respectively. The percentage of milk samples that exceeded the maximum level accepted for AFB1 by the MERCOSUR (0.5ppb) and the European Union regulations (0.05ppb) were 0.81 and 32.65, respectively. The probability distribution of AFM1 concentration in milk was affected by the carry-over rate equations applied in the model. Mycotoxin levels in corn silage and concentrated feeds were the factors most correlated with mycotoxin concentrations in milk. Therefore, agricultural practices, crop management and feed production require prompt attention regarding mycotoxin issues.

Mycoflora study in a wheat flour mill of Argentina.

THE MYCOFLORA OF THE ENVIRONMENT: wheat conditioning, milling and screening, and filling zone, as well as, raw material -wheat-, intermediate product -grits- and end product -flour- on day 1, and after cleaning improvements -days 45 and 90- were studied in an Argentine wheat mill. Samples were incubated at 28°C for 5-7 days on Malt Extract Agar with chloramphenicol (100 mg L(-1)) and the results were expressed in colony forming units per cubic meter of air (CFU m(-3)) or per gram of sample (CFU g(-1)), respectively. Fungal genera and species were isolated and identified and the potential toxicogenic capacity of the Aspergillus flavus and Fusarium graminearum isolated was studied. Time-Place and Time-Product multifactorial ANOVA were carried out. After cleaning improvements, CFU m(-3) of air decreased as a function of time. Cladosporium and Alternaria were abundant in every zone, Aspergillus predominated in the wheat conditioning zone and Penicillium and Eurotium decreased with time. Wheat was more contaminated than grits and flour; Aspergillus, Eurotium and Mucoraceae family were the most abundant. Deoxynivalenol was above the levels allowed in wheat, being acceptable in grits and flour. Aflatoxin and Zearalenone showed acceptable levels. When studied in vitro, 53% of Aspergillus flavus and 100% of Fusarium graminearum isolates, produced Total Aflatoxins, and Deoxynivalenol and Zearalenone, respectively.

Characterization and control of thread mould in cheese.

AIMS: The origin of a mould responsible for the contamination of an Argentinian cheese factory was identified and several antifungal treatments were assessed. METHODS AND RESULTS: Moulds were isolated and identified from vacuum-packed hard cheeses, from the environment and from the surfaces of the factory. A suspension conidia test containing different fungicides was performed; another assay involved the fumigation with p-OH fenilsalicidamide. Only Phoma glomerata was found in all of the mouldy cheeses, and was also obtained from different environments and machine surfaces. The most effective treatments against P. glomerata isolates were 0.5% (w/v) natamycin and 2% (v/v) parabens. Fumigation with p-OH fenilsalicidamide showed no satisfactory results. CONCLUSION: P. glomerata is an important thread mould-contaminating agent in vacuum-packed hard cheeses. SIGNIFICANCE AND IMPACT OF THE STUDY: Taking into account the survival of the conidia of the P. glomerata isolates to different antifungal treatments, the sources of contamination need to be controlled by designing a good factory layout.

Estudio de la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química. Universidad Nacional del Litoral / Study the environmental fungi at the library of the Faculty of Chemical Engineering (UNL)

Se analizó la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química de la Universidad Nacional del Litoral, Santa Fe, a los fines de evaluar los posibles riesgos tantos para la salud de los asistentes como por el probable deterioro de las colecciones existentes. El muestreo se realizó con un equipo SAS (sistema de aire sólido) que aspira 100 litros de aire por minuto, a 1,5 m de altura durante un min., por duplicado, entre las 11,30 y 12,30 horas. Se utilizó MEA + antibiótico (agar extracto de malta, cloranfenicol 100 mg por ciento). Se llevaron a cabo dos muestreos en condiciones ambientales diferentes: Muestreo A: Temperatura 16,5 ºC, Humedad Relativa 75 por ciento, Presión 1015,4 hPa. El salón de publicaciones periódicas presentó una carga fúngica de 25 UFC/m3 y el archivo 95 UFC/m3. Los géneros fúngicos aislados fueron: Cladosporium spp, Penicillium sp, Trichoderma sp, Aspergillus spp, Alternaria sp y Acremonium sp. Muestreo B: Temperatura 20 ºC, Humedad Relativa 95 por ciento, Presión 1013,7 hPa. El salón de publicaciones periódicas presentó una carga fúngica de 290 UFC/m3 y el archivo 360 UFC/m3. Los géros fúngicos aislados fueron: Cladosporium spp, Humicola sp, Aspergillus spp, Alternaria sp y Acremonium sp. Si bien en ambos muestreos no se detectaron valores altos de contaminación, éstos resultaron significativamente superiores en condiciones de humedad relativa y temperatura mayores. Se destaca que alguno de los mohos aislados como: Trichoderma viride y Humicola sp poseen una lata capacidad celulolítica deteriorante y otros: Cladosporium spp, Aspergillus spp, Acremonium sp y Alternaria sp son agentes de reconocida participación en procesos clínicos patógenos y en afecciones alérgicas

Estudio de la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química. Universidad Nacional del Litoral / Study the environmental fungi at the library of the Faculty of Chemical Engineering (UNL)

Se analizó la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química de la Universidad Nacional del Litoral, Santa Fe, a los fines de evaluar los posibles riesgos tantos para la salud de los asistentes como por el probable deterioro de las colecciones existentes. El muestreo se realizó con un equipo SAS (sistema de aire sólido) que aspira 100 litros de aire por minuto, a 1,5 m de altura durante un min., por duplicado, entre las 11,30 y 12,30 horas. Se utilizó MEA + antibiótico (agar extracto de malta, cloranfenicol 100 mg por ciento). Se llevaron a cabo dos muestreos en condiciones ambientales diferentes: Muestreo A: Temperatura 16,5 ºC, Humedad Relativa 75 por ciento, Presión 1015,4 hPa. El salón de publicaciones periódicas presentó una carga fúngica de 25 UFC/m3 y el archivo 95 UFC/m3. Los géneros fúngicos aislados fueron: Cladosporium spp, Penicillium sp, Trichoderma sp, Aspergillus