Transformación de la aflatoxina B1 de alimentos, en el cancerígeno humano, aducto AFB1-ADN

Aspergillus flavus and Total Aflatoxins Occurrence in Dairy Feed and Aflatoxin M1 in Bovine Milk in Aguascalientes, Mexico

Contamination of food chains by toxigenic fungi and aflatoxins is a global problem that causes damage to human health, as well as to crop and livestock production. The objective is to evaluate Aspergillus flavus and total aflatoxins (AFs) occurrence in totally mixed rations (TMRs) for dairy cows and aflatoxin M1 (AFM1) in milk for human consumption. Ninety-nine dairy production units located in Aguascalientes, Mexico, were randomly selected, and samples were collected from TMRs, raw milk, and milk marketed in the city in two consecutive agricultural cycles. AFs were quantified in TMRs and milk by indirect enzyme immunoassay and HPLC; aflatoxigenic and molecular (PCR) capacity of monosporic A. flavus isolates in the feed was characterized. All feed, raw, and pasteurized milk samples showed aflatoxin contamination (26.0 ± 0.4 µg/kg, 32.0 ± 1.0, and 31.3 ± 0.7 ng/L, respectively), and a significant proportion (90.4, 11.3, and 10.3%) exceeded the locally applied maximum permissible limits for feed and milk (20.0 µg/kg and 50 ng/L). Aflatoxin contamination in both TMRs and milk indicated a seasonal influence, with a higher concentration in the autumn-winter cycle when conditions of higher humidity prevail. The results obtained suggest the existence of contamination by aflatoxigenic A. flavus and aflatoxins in the diet formulated for feeding dairy cows and, consequently, in the dairy food chain of this region of the Mexican Highland Plateau.

[Quantification of carcinogenic aflatoxins in unprocessed foods and their implication for consumption in Lima, Peru]

Introduction

Introduction and objectives: aflatoxins are secondary metabolites produced by fungi of the Aspergillus and Penicillium geni. These fungi contaminate cereals and several other types of food. The pathophysiologic effects of aflatoxins in humans include liver cancer, cirrhosis, and accumulation in human tissues. The study aimed to quantify carcinogenic aflatoxins in unprocessed food sold in the foodstuff markets of 13 districts of the city of Lima, Perú, and to discuss their effects for public health. Methods: in order to so, we performed an immunoenzymatic assay using a Veratox® kit for total aflatoxin to detect aflatoxins in food for human consumption, and the implications of our findings for public health. Results: the most contaminated foods we found included peanuts (Arachis hypogaea) (149.7 ppb) from the Limoncillo market at the Rimac district, and "ají panca" or Peruvian red chili pepper (Capsicum chinense) (56.4 ppb) from the central market at the Comas district. Peanuts may be eaten raw in pasta or creams, and Capsicum chinense is also eaten sometimes raw, always in a sustained manner over time as part of typical Peruvian cuisine. Conclusions: we demonstrated a high risk to public health due to the link between aflatoxins in these foods and mainly liver cancer, in a city where the hepatic cancer and gastric cancer are prevalent.