Níveis de congêneres, carbamata de etila e outros contaminantes em vodcas e cachaças de consumo popular no Brasil

Abstract

Ethyl carbamate (EC, C2H5OCONH2) or urethane is a known carcinogen and genotoxic substance that occurs in various fermented foods, in particular spirits. In 2005, after several studies had shown that cachaça, the most consumed spirit in Brazil, was heavily contaminated with EC, the Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA) established an EC limit (150 μg.L-1) for the beverage (to come into effect in June 2012), but other consumed spirits in Brazil, such as vodka, were not subjected to any EC control. Given the lack of information on EC levels and chemical profiles of Brazilian vodkas, along with the effects of new EC regulation for cachaça, the objective of this study was to determine the levels of congeners (volatile acidity, aldehydes, esters, higher alcohols and furfural), EC and other contaminants (methanol, copper, lead and arsenic) in vodkas and cachaças produced in Brazil. Twenty three brands of “industrial” cachaças (i.e. cachaças produced on a large scale and distilled in columns) and twenty one brands of vodkas were sampled. The brands were low-priced (below US$11.00 per 600-1000 mL bottle) and recorded (licit). All sampled cachaças and vodkas complied with MAPA regulation for alcoholic strength, volatile acidity, methanol, aldehydes, esters, higher alcohols, furfural, total congeners, copper, lead and arsenic. EC levels in cachaça ranged from 10 μg.L-1 (limit of detection, LD) to 713 μg.L-1, average 245 μg.L-1, with 15 brands (65 %) exceeding 150 μg.L-1. EC levels in all sampled vodkas were below the LD. The vodka results are probably related to its distillation process, in particular the use of extractive and rectification columns (column rectification system), which allow production of high strength spirits with very low levels of congeners. This is not the case usually found in “industrial” cachaça plants, where a smaller single distillation column, with fewer trays, is used. This cachaça distillation system does not seem to promote the same efficiency in congeners reduction, especially for highly volatile “head” products (including cyanide, precursor of EC), when compared to the column rectification system used in vodka.