Occurrence of aflatoxins in peanuts and peanut products consumed in the State of São Paulo/Brazil from 1995 to 1997

Abstract

One hundred and thirty seven samples of peanuts and peanut containing foods were collected in markets in the State of São Paulo, Brazil, between January 1995 an December 1997. Most of the samples were collected by the Inspection Service of São Paulo Secretary of Health. The foods included raw peanuts, peanut candies ("paçoca" and "pé de moleque"), peanut butter, fried/roasted salted peanuts, "torrone", chocolate coated peanuts and salt-coated peanuts. The samples were analyzed for aflatoxins using a thin-layer chromatographic method. About 45% of the samples were positive for aflatoxins and 27% exceeded the limits of the Brazilian legislation (30.0 µg.kg-1 for aflatoxins B1+G1). The aflatoxins were confirmed by derivatization with trifluoroacetic acid. The 90th percentile was 110.0 in 1995, 60.0 in 1996 and 118.0 µg.kg-1 in 1997. The aflatoxins concentration in the raw peanut samples ranged from 5.0 to 382.0 µg.kg-1 and 27.1% were above the legal limits. Contamination in peanut candies was above the limit in 32.8% of the samples and the aflatoxins levels ranged from 6.0 to 494.0 µg.kg-1. Contamination of salty peanuts was less frequent, around 10% of the samples and the toxin levels were usually below 10 µg.kg-1. The maximum level of contamination, 536.0 µg.kg-1, was found in a sample of peanut with a salty coat ("amendoim japonês"). Results of previous studies in peanuts and peanut products in the city of São Paulo from 1980-1987 had 68.75% of the samples with levels greater than the limit 30.0 µg.kg-1 and the 90th percentile ranged from 42.0 to 333.0 µg.kg-1. In 1994, 36.0% of the samples showed results above the limit and the 90th percentile was 489 µg.kg-1. The results show that aflatoxins contamination in peanuts is decreasing but it is still a serious problem in Brazil, a country where the climate, the agricultural practices and storage conditions favour fungal growth.