Green and brown propolis: efficient natural biocides for the control of bacterial contamination of alcoholic fermentation of distilled beverage

Abstract

This study aimed to evaluate the efficiency of natural biocides, brown and green propolis, for the control of bacterial contamination in the production of sugarcane spirit. The treatments consisted of brown and green propolis extracts, ampicillin, and a control and were assessed at the beginning and end of harvest season in ten fermentation cycles. In the microbiological analyses, the lactic acid bacteria were quantified in the inoculum before and after the treatment with biocides, and the viability of yeast cells during fermentation was evaluated. The levels of acids, glycerol, total residual reducing sugars, and ethanol were analyzed for the wine resulting from each fermentation cycle. A reduction in the number of bacterial contaminants in the inoculum in the treatments with the natural biocides was observed, but it did not affect the viability of yeast cells. The control of the contaminants led to the production of higher levels of ethanol and reduced acidity in the wine produced. The results of the use of brown and green propolis to control the growth microorganisms in the fermentation of sugarcane spirit can be of great importance for using alternative strategies to synthetic antibacterials in fermentation processes including other distilled beverage or spirits.

New emerging fields of application of propolis

“…Bebedouro-SP, Brazil: green propolis; Formiga-MG, Brazil: brown propolis [66] Distilled beverage (sugarcane spirit) 80% Ethanol extract Brazilian green and brown propolis type [67] Fruits Mandarins Ethyl acetate extract Hebei Province, China [68] Orange 96% Ethanol extract Iraq (Baghdad) [69] Apple 96% Ethanol extract Iraq (Baghdad) [70] Sweet cerry Ethanol and water extracts Hatay province, Turkey [71] Grapefruit cv. Star Ruby 70% Ethanol extract Hatay province, Turkey [72] 'Kent' mango fruits 70% Ethanol extract Brazilian green type [73] Dragon fruit 80% Ethanol extract Selangor state Malaysia; China [74,75] Papaya 95% Ethanol extract China [76] …”

Propolis as a potential alternative for the control of Dekkera bruxellensis in bioethanol fermentation

“…They found that the viability of S. cerevisiae did not change significantly with any antimicrobial substance, indicating that treatments used at their recommended doses do not eliminate yeast cells from the fermentation process. On the other hand, Mutton et al (2014) evaluated the efficiency of brown and green propolis to control bacterial contamination in the production of sugarcane spirit. They observed a reduction in the number of bacterial contaminants with the natural biocides, which did not affect the viability of yeast cells.…”

Influência do tratamento térmico do caldo de cana no desenvolvimento do processo fermentativo e na composição química da cachaça

“…Verificou-se que as maiores contagens de leveduras totais ocorreram nas fermentações conduzidas com caldo de cana submetido ao tratamento térmico. Possivelmente, a inativação térmica dos microrganismos naturais do caldo favoreceu a atividade das leveduras no processo devido à maior disponibilidade de Influência do tratamento térmico do caldo de cana no desenvolvimento do processo fermentativo e na composição química da cachaça Alves, T. M. et al Os vinhos destinados à produção de cachaça geralmente possuem uma concentração alcoólica de 7% a 8% (OLIVEIRA FILHO et al, 2016;MUTTON et al, 2014), valores estes próximos ao encontrado no presente estudo. Entretanto, verificou-se que a assimilação dos açúcares do meio foi comprometida ao final dos processos fermentativos, devido aos elevados valores de açúcares residuais nos vinhos.…”

“…Uma diversidade de microrganismos pode se desenvolver nesta etapa, decorrente das alimentações sucessivas de caldo e das condições intrínsecas do processo (pH, concentração de etanol, disponibilidade de substrato e temperatura), sendo estes responsáveis pela produção dos compostos químicos que caracterizam o destilado (BADOTTI et al, 2010a;DUARTE et al, 2013;GOMES et al, 2010;MUTTON et al, 2014).…”

“…O controle dos microrganismos existentes no processo fermentativo é extremamente importante, pois contribui com a manutenção do número de células viáveis de leveduras, a menor síntese de ácidos orgânicos e o aumento da produção de álcool no vinho (MUTTON et al 2014).…”