Diet is the main source of mycotoxins for man. Mycotoxigenic fungi can contaminate plant products in field, during storage or in processing. Although mycotoxins are mostly thermostable, evaluating their presence in the different components of our diet including ready-to-eat vegetable or animal dishes, as well as in dairy products, juices and alcoholic beverages is a necessary step for a better assessment of the risks associated with mycotoxin presence and to take measures to protect the health of consumers. In the first place, a bibliographic review was carried out in this thesis including eighteen total diet studies carried out in Canada, China, France, Ireland, Lebanon, New Zealand, Spain, the Netherlands, Viet Nam, and Spain, showing the growing interest in exposure assessment to mycotoxins through diet. Likewise, different analytical procedures based on gas chromatography and liquid both coupled to tandem mass spectrometry were developed and validated. Different extraction techniques have been used; QuEChERS method that gave very good results for cereals, vegetables, fruits, nuts, legumes, meat, fish and milk, while the liquid-liquid extraction was used for coffee and the liquid-liquid dispersive microextraction for beer, wine, juices and teas. The proposed methodologies have been validated according to European regulations with satisfactory results in terms of linearity, accuracy, precision and limits of detection and quantification. The results showed that 49% of the 328 menu dishes ready for consumption contained at least one mycotoxin. The mycotoxins most frequently detected were deoxynivalenol, neosolaniol, HT-2 toxin and alternariol. 53% of 110 alcoholic beverages have shown simultaneous presence of more than one mycotoxin reaching up to ten, mainly of trichothecenes, aflatoxins, zearalenone, patulin and Alternaria toxins with sums of concentrations ranging between 5.50 μg / L and 180.15 μg / L. The concentrations of the mycotoxins detected in the food are below the maximum limits established except for a sample of wine that exceeded the levels established for OTA (2 μg / L). An evaluation of the exposure was carried out taking into account the results obtained and the consumption data, and a special mention was made to the consumption according to the recommendations of the Mediterranean diet. The technique of multivariate statistical analysis of the principal components analysis (PCA) was used to interpret the results in terms of the contribution of the analyzed foods to the ingestion of mycotoxins studied. The results showed a greater contribution of legumes to the intake of HT-2 and βZAL, of meat to the intake of OTA, of beer to the intake of AOH, βZAL and DON, of fruit juices to the intake of PAT as well as of dried fruits to the intake of NIV. In addition, the characterization of the risk has been made by comparing the estimated daily intake with toxicological parameters of tolerable daily intake, obtaining a low risk for most of the food ready for consumption. However, the detection of mycotoxins, although at low levels, highlights the need to include mycotoxin monitoring in total diet studies. Diet is the main source of mycotoxins for man. Mycotoxigenic fungi can contaminate plant products in field, during storage or in processing. Although mycotoxins are mostly thermostable, evaluating their presence in the different components of our diet including ready-to-eat vegetable or animal dishes, as well as in dairy products, juices and alcoholic beverages is a necessary step for a better assessment of the risks associated with mycotoxin presence and to take measures to protect the health of consumers. In the first place, a bibliographic review was carried out in this thesis including eighteen total diet studies carried out in Canada, China, France, Ireland, Lebanon, New Zealand, Spain, the Netherlands, Viet Nam, and Spain, showing the growing interest in exposure assessment to mycotoxins through diet. Likewise, different analytical procedures based on gas chromatography and liquid both coupled to tandem mass spectrometry were developed and validated. Different extraction techniques have been used; QuEChERS method that gave very good results for cereals, vegetables, fruits, nuts, legumes, meat, fish and milk, while the liquid-liquid extraction was used for coffee and the liquid-liquid dispersive microextraction for beer, wine, juices and teas. The proposed methodologies have been validated according to European regulations with satisfactory results in terms of linearity, accuracy, precision and limits of detection and quantification. The results showed that 49% of the 328 menu dishes ready for consumption contained at least one mycotoxin. The mycotoxins most frequently detected were deoxynivalenol, neosolaniol, HT-2 toxin and alternariol. 53% of 110 alcoholic beverages have shown simultaneous presence of more than one mycotoxin reaching up to ten, mainly of trichothecenes, aflatoxins, zearalenone, patulin and Alternaria toxins with sums of concentrations ranging between 5.50 μg / L and 180.15 μg / L. The concentrations of the mycotoxins detected in the food are below the maximum limits established except for a sample of wine that exceeded the levels established for OTA (2 μg / L). An evaluation of the exposure was carried out taking into account the results obtained and the consumption data, and a special mention was made to the consumption according to the recommendations of the Mediterranean diet. The technique of multivariate statistical analysis of the principal components analysis (PCA) was used to interpret the results in terms of the contribution of the analyzed foods to the ingestion of mycotoxins studied. The results showed a greater contribution of legumes to the intake of HT-2 and βZAL, of meat to the intake of OTA, of beer to the intake of AOH, βZAL and DON, of fruit juices to the intake of PAT as well as of dried fruits to the intake of NIV. In addition, the characterization of the risk has been made by comparing the estimated daily intake with toxicological parameters of tolerable daily intake, obtaining a low risk for most of the food ready for consumption. However, the detection of mycotoxins, although at low levels, highlights the need to include mycotoxin monitoring in total diet studies.La dieta es la principal fuente de micotoxinas para el hombre. Los hongos micotoxigénicos pueden contaminar los productos vegetales en el campo, durante el almacenamiento o en el procesado. Aunque las micotoxinas son en su mayoría termostables, evaluar su presencia en los diferentes componentes de nuestra dieta incluyendo platos listos para su consumo de composición vegetal y animal, así como en productos lácteos, zumos y bebidas alcohólicas es un paso necesario para evaluar mejor los riesgos asociados a su presencia y adoptar medidas para proteger la salud de los consumidores. En primer lugar, se realizó en esta tesis una revisión bibliográfica que incluyó dieciocho estudios de dieta total realizados en Canadá, China, Francia, Irlanda, Líbano, Nueva Zelanda, España, Paises Bajos, Viet Nam, y España, mostrando el creciente interés por la exposición a las micotoxinas a través de la dieta. Así mismo, se desarrollaron y validaron diferentes procedimientos analíticos basados en la cromatografía de gases y liquida ambas acopladas a espectrometría de masas en tándem. Se han utilizado diferentes técnicas de extracción; como método QuEChERS que dio muy buenos resultados para cereales, vegetales, frutas, frutos secos, legumbres, carne, pescado y leche, mientras que para el café se usó la extracción liquida-liquida y para cerveza, vino, zumos y tés se seleccionó la microextracción liquida-liquida dispersiva. Las metodologías propuestas han sido validada de acuerdo a la normativa europea con resultados satisfactorios en cuanto a linealidad, exactitud, precisión y límites de detección y cuantificación. Los resultados mostraron que el 49% de las 328 platos de menús listos para su consumo contenían al menos una micotoxina. Las micotoxinas más frecuentemente detectadas fueron deoxinivalenol, neosolaniol, toxina HT-2 y alternariol. EL 53% de las 110 bebidas alcohólicas han mostrado presencia simultánea de más de una micotoxina llegando hasta diez, principalmente de tricotecenos, aflatoxinas, zearalenona, patulina y toxinas Alternarias con sumas de concentraciones que oscilan entre 5.50 µg/L y 180.15 µg/L. Las concentraciones de las micotoxinas detectadas en los alimentos se encuentran por debajo de los límites máximos establecidos a excepción de una muestra de vino que excedía los niveles establecidos para OTA (2 µg/L). Se llevó a cabo una evaluación de la exposición teniendo en cuenta los resultados obtenidos y los datos de consumo, y se hizo una mención especial al consumo según las recomendaciones de la dieta mediterránea. Se utilizó la técnica de análisis estadístico multivariado del análisis de componentes principales (PCA), para interpretar los resultados en términos de contribución de los alimentos analizados a la ingesta de micotoxinas estudiadas. Los resultados mostraron una mayor contribución de legumbres a la ingesta de HT-2 y βZAL , de carne a la ingesta de OTA, de cerveza a la ingesta de AOH, βZAL y DON, de zumos de frutas a la ingesta de PAT así como de frutos secos a la ingesta de NIV. Además, se ha realizado la caracterización del riesgo mediante comparación de la ingesta diaria estimada con parámetros toxicológicos de ingesta diaria tolerable obteniendo un riego bajo para la mayoría de los alimentos listos para su consumo. Sin embargo, la presencia frecuente de micotoxinas aunque a bajos niveles, pone de manifiesto la necesidad de incluir la monitorización de micotoxinas en estudios de dieta total.