Ethyl carbamate in cachaça (Brazilian sugarcane spirit): Extended survey confirms simple mitigation approaches in pot still distillation

Abstract

In 2009, we reported an association between low levels of ethyl carbamate (EC) in pot still cachaças from Paraíba State, Brazil, and distillation in copper pot stills equipped with cooled columns. To strengthen these observations, we extended our study to Pernambuco State and assessed 13 pot still and 20 column still cachaça brands. An EC range from <40 to 532μg/l was found; 18 brands exceeded the Brazilian limit (150μg/l), 89% of which were column still types. Mean EC concentration of pot still cachaças was very low (64μg/l), and was well below the Paraíba study (220μg/l). An on-site investigation of pot still distilleries associated with <40μg/l brands showed a connection to differences in the distillation apparatus. Maximising distillation reflux ratios in the ascending parts and minimising exposure to copper in the descending parts (through the use of stainless steel) can reduce EC, and also avoid copper contamination.

Comparação do perfil químico entre cachaças de um mesmo vinho destiladas em alambiques e em colunas

“…Foi sugerido anteriormente, 14,[18][19][20] que as cachaças destiladas em colunas de aço inox, em geral, apresentam concentrações de carbamato de etila superiores às das cachaças de alambique. A Tabela 1 apresenta teores de carbamato de etila para as três frações de alambique e do correspondente destilado de coluna, considerando-se em cada linha, o mesmo vinho.…”

Quantitative chemical profile and multivariate statistical analysis of alembic distilled sugarcane spirit fractions

“…The results suggest that a tuning in the first cut could be used to reduce the concentration of this unwanted compound in the heart fraction. 24 The sum of acetic and lactic acid concentrations accounts for more than 90% of the total organic acid content in the alembic fractions. The sum acetic, lactic, glycolic, succinic and citramalic acids, more soluble in water than in ethanol and with boiling points ranging from 112-235 o C, presented higher concentrations in the tail fraction than in the head fraction.…”

Chemical Analysis of Suspected Unrecorded Alcoholic Beverages from the States of São Paulo and Minas Gerais, Brazil

“…The FT-IR spectra of various samples of unrecorded beverages showed a large band in 2145 cm −1 that was attributed to the asymmetric vibration of the cyanate (NCO) − in the cyanate-copper complexes [10, 11, 29, 30], as can be seen in Figure 1. According to Baffa Junior et al [10], the formation of EC from HCN is based on the complexation of HCN to copper, followed by its oxidation to HCNO, which reacts with ethanol to form EC.…”

“…Ethanol shows three bands: an intense band at 1046 cm −1 and two other bands of medium intensity, centered at 1086 and 879 cm −1 , respectively. These bands are due to vibrational transitions of the C–O–H system: C–O stretching vibration ( p -OH) and O–H bending vibration out of plane [25, 29]. The ethanol quantification was carried out using the analytical band at 1046 cm −1 (Figure 1) in the FT-IR.…”

“…According to Baffa Junior et al [10], the formation of EC from HCN is based on the complexation of HCN to copper, followed by its oxidation to HCNO, which reacts with ethanol to form EC. Copper acts as an important catalyst in the conversion of HCN into EC in cachaça [29, 30]. …”