Melhoramento das condições de hidratação da levedura seca instantânea de panificação por tratamentos com soluções de aditivos
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Data
2008-02-29
Autores
Thomaz, Daniel [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A hidratação é uma fase crítica no uso da levedura seca instantânea por depender do meio líquido usado, da temperatura e do tempo de hidratação. A levedura seca apresenta-se como um material biológico de grande heterogeneidade celular. Hidratação direta do fermento seco com soluções de aditivos, bem como, o tratamento do fermento seco, mas previamente hidratado com água foram acompanhados por medidas de viabilidade e atividade de fermentação (variações em volume de massa e evolução de CO2). O efeito do tempo de abertura da embalagem do fermento seco sobre as variações em viabilidade celular teores de glicerol interno e atividade de fermentação também foram determinados. Os seguintes tratamentos foram aplicados a levedura, previamente hidratada em água: (a) incubação em solução de citrato; (b) aplicação de choque térmico as células suspensas em solução de citrato. A levedura seca foi hidratada diretamente em água a temperatura ambiente e em solução de lisina a 37oC. As hidratações diretas do fermento seco com soluções de citrato 0,15 mol.L-1 a pH 6,9 e 7,5 por 40 min a temperatura ambiente proporcionaram aumentos em volume de massa da ordem de 25-29% (35,4-36,6 mL/180 min de fermentação) em relação ao controle (28,3 mL/180 min de fermentação). No entanto, a hidratação direta do fermento seco com água por 10 min a temperatura ambiente proporcionou um volume de massa (36,0 mL/150 min de fermentação) tão bom quanto aos obtidos com solução de citrato, mas com tempos de hidratação e fermentação menores. As hidratações diretas, do fermento seco, com soluções de glicose 2,0% e 0,5% por 40 min a temperatura ambiente proporcionaram aumentos em volume de CO2 da ordem de 33-38% (53,7-56,0 mL/180 min de fermentação) em relação ao controle (40,5 mL/180 min de fermentação).
Hydration is a critical phase in the use of instant dry yeast because it depends on the liquid media used, temperature and hydration time. Instant dry yeast is showed as biological material of great cellular heterogeneity. Direct hydration of instant dry yeast in additive solutions as well as the treatment of the instant dry yeast, but previously hydrated in water, were followed by viability measures and activity of fermentation (variations in dough volume and CO2 evolution). The time effect of the opened packing of the instant dry yeast on the fermentation activity, the internal glycerol and the cellular viability variations were also determined. The following treatments were applied to yeast, previously hydrated in water: a) incubation in citrate solution; b) application of heat shock to suspension cells in citrate solution. Instant dry yeast was directly hydrated in water at room temperature and in lysine solution at 37oC. Direct hydrations of instant dry yeast in 0,15 mol.L-1 citrate solutions at pH 6.9 and 7.5 for 40 min at room temperature provided increases in dough volume around 25- 29% (35.4-36.6 mL/180 min of fermentation) in relation to the control (28.3 mL/180 min of fermentation). However, direct hydration of instant dry yeast in water for 10 min at room temperature provided a dough volume (36.0 mL/150 min fermentation) as good as the ones obtained after citrate hydration, but with shorter hydration and fermentation time. Direct hydration of instant dry yeast in 2.0% e 0.5% glucose solutions for 40 min at room temperature provided increases in CO2 evolution around 33-38% (53.7-56,0 mL/180 min of fermentation) in relation to the control (40.5 mL/180 min of fermentation). However, direct hydration of instant dry yeast in water for 10 min at room temperature provided a CO2 evolution (79.0 mL/180 min of fermentation) bigger than the CO2 evolution previously obtained with glucose hydration.
Hydration is a critical phase in the use of instant dry yeast because it depends on the liquid media used, temperature and hydration time. Instant dry yeast is showed as biological material of great cellular heterogeneity. Direct hydration of instant dry yeast in additive solutions as well as the treatment of the instant dry yeast, but previously hydrated in water, were followed by viability measures and activity of fermentation (variations in dough volume and CO2 evolution). The time effect of the opened packing of the instant dry yeast on the fermentation activity, the internal glycerol and the cellular viability variations were also determined. The following treatments were applied to yeast, previously hydrated in water: a) incubation in citrate solution; b) application of heat shock to suspension cells in citrate solution. Instant dry yeast was directly hydrated in water at room temperature and in lysine solution at 37oC. Direct hydrations of instant dry yeast in 0,15 mol.L-1 citrate solutions at pH 6.9 and 7.5 for 40 min at room temperature provided increases in dough volume around 25- 29% (35.4-36.6 mL/180 min of fermentation) in relation to the control (28.3 mL/180 min of fermentation). However, direct hydration of instant dry yeast in water for 10 min at room temperature provided a dough volume (36.0 mL/150 min fermentation) as good as the ones obtained after citrate hydration, but with shorter hydration and fermentation time. Direct hydration of instant dry yeast in 2.0% e 0.5% glucose solutions for 40 min at room temperature provided increases in CO2 evolution around 33-38% (53.7-56,0 mL/180 min of fermentation) in relation to the control (40.5 mL/180 min of fermentation). However, direct hydration of instant dry yeast in water for 10 min at room temperature provided a CO2 evolution (79.0 mL/180 min of fermentation) bigger than the CO2 evolution previously obtained with glucose hydration.
Descrição
Palavras-chave
Bioquímica, Panificação, Leveduras - Bioquímica
Como citar
THOMAZ, Daniel. Melhoramento das condições de hidratação da levedura seca instantânea de panificação por tratamentos com soluções de aditivos. 2008. 79 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química., 2008.