Loading...
Publication
Evolution of staling aldehydes on lager beer stability: impact of maritime transport and storage condidtions
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 2.03 MB | Adobe PDF |
Abstract(s)
A estabilidade organolética da cerveja engarrafada é atualmente um dos principais desafios da
indústria cervejeira. Não obstante à contribuição de inúmeras substâncias, os compostos
carbonilos, em particular os aldeídos, são responsáveis por muitas das mudanças desfavoráveis
e percetíveis ao consumidor. Estas modificações são favorecidas por temperaturas não
refrigeradas, armazenamento durante períodos longos, vibrações induzidas pelo transporte,
entre outros fatores. Atualmente, existem ainda poucos dados na literatura científica sobre o
impacto das condições reais de transporte, nomeadamente impacto das vibrações e temperaturas
não refrigeradas, na estabilidade organolética da cerveja.
O presente trabalho teve como objetivo avaliar a evolução de 10 aldeídos em cerveja Lager
engarrafada durante exportação por via marítima e armazenamento no destino. Para tal,
simulou-se as condições reais que a cerveja produzida localmente é submetida, nomeadamente
temperatura (19-30ºC), vibração (1.7 Hz) e tempo (até 120 dias). A análise dos compostos em
estudo foi realizada por micro-extração em fase sólida seguida por cromatografia gasosa
acoplada a espetrometria de massa.
Os resultados obtidos revelaram que as condições de transporte (influência de tempo,
temperatura e vibração) e armazenamento (tempo, temperatura) simuladas i) promoveram o
aumento médio na concentração dos aldeídos de Strecker, de 65%, ii) enquanto os aldeídos
formados a partir oxidação lipídica bem como o acetaldeído, regra geral, não apresentam
variações significativas neste período. O aumento descrito em i) apresentou dois padrões:
garrafas com abertura tradicional (carica) apresentavam valores médios de 131.6±9.9 e
190.3±9.4 µg/L enquanto garrafas com um sistema de abertura fácil 190.5±10.0 e 180.3±9.5
µg/L, após transporte e armazenamento respetivamente.
O fenilacetaldeído foi o composto com maior variação nas condições estudadas, aumentando de
94.7±7.3 (cerveja fresca) para 143.6±8.0 e 168.9±8.9 µg/L, após transporte e considerando um
período adicional de armazenamento, respetivamente.
Adicionalmente, verificou-se que o procedimento de envelhecimento forçado tipicamente
adotado, pode apresentar limitações a reproduzir as condições reais em alguns compostos. Em
particular, destaca-se o benzaldeído, que em qualquer período de envelhecimento forçado, 7, 14 e 28 dias, apresentou concentrações, em média, inferiores, de 5.3±0.3 µg/L, 5.4±0.3 µg/L e
5.4±0.3 µg/L, respetivamente, em comparação com o teor real ao fim de 120 dias, de 6.4±0.4
µg/L.
The flavour stability of bottled beer is the main challenge of the brewing industry. Carbonyl compounds, in particular aldehydes, are responsible for the unfavourable and perceptible changes detected by consumers. Those modifications are favoured by unrefrigerated temperatures, prolonged storage, transport-induced vibrations, among other factors. Currently, there are few data in the scientific literature on the impact of real transport conditions, namely vibrations and unrefrigerated temperatures, on beer stability. The aim of this study was to evaluate the evolution of 10 aldehydes in bottled Lager beer during maritime exportation and storage at the destination. To this end, the real conditions that the locally produced beer is subjected to, namely temperature (19-30ºC), vibration (1.7 Hz) and time (up to 120 days) were simulated. The analysis of the compounds under study was performed by solid-phase microextraction followed by gas chromatography coupled with mass spectrometry. The results revealed that the conditions of transport and storage simulated i) promoted an average increase in the concentration of Strecker aldehydes of 65%, ii) while the aldehydes formed from lipid oxidation as well as acetaldehyde, in general, do not present significant variations. The increase described in i) presented two patterns: bottles with traditional cap had mean values of 131.6±9.9 and 190.3±9.4 µg/L while bottles with a ring pull cap had 190.5±10.0 and 180.3±9.5 µg/L, after transport and storage respectively. Phenylacetaldehyde was the compound with the greatest variation, increasing from 94.7±7.3 (fresh beer) to 143.6±8.0 and 168.9±8.9 µg/L, after transport and considering an additional storage period, respectively. Additionally, it was found that the forced ageing procedure typically adopted may have limitations in reproducing the real conditions. Benzaldehyde stands out, which in any period of forced ageing, 7, 14 and 28 days, presented concentrations, on average, lower, of 5.3±0.3 µg/L, 5.4±0.3 µg/L and 5.4±0.3 µg/L, respectively, compared to the actual content after 120 days, of 6.4±0.4 µg/L.
The flavour stability of bottled beer is the main challenge of the brewing industry. Carbonyl compounds, in particular aldehydes, are responsible for the unfavourable and perceptible changes detected by consumers. Those modifications are favoured by unrefrigerated temperatures, prolonged storage, transport-induced vibrations, among other factors. Currently, there are few data in the scientific literature on the impact of real transport conditions, namely vibrations and unrefrigerated temperatures, on beer stability. The aim of this study was to evaluate the evolution of 10 aldehydes in bottled Lager beer during maritime exportation and storage at the destination. To this end, the real conditions that the locally produced beer is subjected to, namely temperature (19-30ºC), vibration (1.7 Hz) and time (up to 120 days) were simulated. The analysis of the compounds under study was performed by solid-phase microextraction followed by gas chromatography coupled with mass spectrometry. The results revealed that the conditions of transport and storage simulated i) promoted an average increase in the concentration of Strecker aldehydes of 65%, ii) while the aldehydes formed from lipid oxidation as well as acetaldehyde, in general, do not present significant variations. The increase described in i) presented two patterns: bottles with traditional cap had mean values of 131.6±9.9 and 190.3±9.4 µg/L while bottles with a ring pull cap had 190.5±10.0 and 180.3±9.5 µg/L, after transport and storage respectively. Phenylacetaldehyde was the compound with the greatest variation, increasing from 94.7±7.3 (fresh beer) to 143.6±8.0 and 168.9±8.9 µg/L, after transport and considering an additional storage period, respectively. Additionally, it was found that the forced ageing procedure typically adopted may have limitations in reproducing the real conditions. Benzaldehyde stands out, which in any period of forced ageing, 7, 14 and 28 days, presented concentrations, on average, lower, of 5.3±0.3 µg/L, 5.4±0.3 µg/L and 5.4±0.3 µg/L, respectively, compared to the actual content after 120 days, of 6.4±0.4 µg/L.
Description
Keywords
Exportação Vibrações Temperatura Tempo de armazenamento em garrafa Compostos carbonilos Envelhecimento forçado Beer export Vibrations Temperature Storage time Off-flavours Forced ageing Applied Biochemistry . Faculdade de Ciências Exatas e da Engenharia