The effect of roasting on the fate of aflatoxin B1 in artificially contaminated green coffee beans.

A study was undertaken to evaluate aflatoxin B1 contamination in coffee beans. 41 samples of green coffee were collected from large lots of material by representative sampling. The raw samples were analyzed and showed no detectable levels of aflatoxin B1. In order to establish the heat stability of the toxin, 3 artificially contaminated samples (average level 10/μg/kg) were roasted atca 200°C for different operation times periods so as to reproduce light and dark roasting procedures. Each sample was roasted both electrically and by gas.The percentage of toxin destruction was up to 93% for light roasted and 99% for dark roasted coffee with a slightly higher rate up to 100% for the electrically roasted coffee for light and dark roasting. In order to evaluate the potential migration of the aflatoxin B1 into the coffee beverage, 1 sample found contaminated after roasting treatment (0.8/°g/kg) was extracted using each of the 3 most common types of coffee makers. Additional destruction of the toxin was observed (up to 99%) in two cases while only 75% of fate was obtained in the third.The process from raw coffee beans to beverage showed a meaningful destruction of aflatoxin B1, ranging from 97 to 100% depending on the extraction technique adopted in the preparation of the beverages.