Isolado protéico de semente de goiaba (Psidium guajava): caracterização de propriedades funcionais
Carregando...
Data
2007-08-01
Autores
Fontanari, Gustavo Guadagnucci [UNESP]
Jacon, Mônica Cristina [UNESP]
Pastre, Ieda Aparecida [UNESP]
Fertonani, Fernando Luís [UNESP]
Neves, Valdir Augusto [UNESP]
Batistuti, José Paschoal [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Resumo
Isolados protéicos (IPs) foram obtidos a partir da farinha da semente de goiaba (Psidium guajava) por extração a diferentes pHs seguido de precipitação isoelétrica (pI 4,5). As condições para o preparo do IP foram definidas a partir da curva de solubilidade, em pH 10,0 e 11,5, na ausência de NaCl e em temperatura de 25 ± 3 ºC. Essas condições levaram a um rendimento na extração de 45,19 e 66,23%, e teor protéico de 96,4 e 93,5% para IP 10,0 e 11,5, respectivamente. Capacidade de absorção de água e óleo de 1,05 ± 0,07 e 2,30 ± 0,01 mL.g-1 proteína e 1,65 ± 0,07 e 1,70 ± 0,07 mL.g-1 proteína foram obtidos, respectivamente, para IP 10,0 e IP 11,5. Não foram observadas diferenças entre os IPs quanto à atividade e estabilidade de emulsão, atingindo valores similares e superiores ao IP de outras sementes. Formação de gel, em pH neutro e ausência de sal, exigiram concentrações de 8 e 10% para IP 10,0 e IP 11,5, respectivamente. Maior capacidade de formação de espuma foi obtida para IP 10,0 em pH neutro e alcalino, apresentando valores de até 90% do volume inicial, por outro lado, para estabilidade de espuma, ambos IPs apresentaram boas propriedades até duas horas após a formação da espuma.
Protein isolates (PIs) were obtained from the guava seed flour (Psidium guajava) by extracting different pHs followed by isoelectric precipitation (pH 4.5). The conditions for preparation of the PIs were defined from the solubility curve at pH 10.0 and 11.5, in the absence of NaCl and a temperature of 25 ± 3 ºC. These conditions obtained protein isolated (PI) with extraction yield of 45.19 and 66.23%, with protein content of 96.4 and 93.5% for PI 10.0 and 11.5, respectively. The water and oil absorption capacity of 1.05 ± 0.07 and 2.30 ± 0.01 mL.g-1 protein and 1.65 ± 0.07 and 1.70 ± 0.07 mL.g-1 protein, respectively; were obtained for PI 10.0 and PI 11.5. Differences among the PIs regarding the emulsion activity and stability were not observed, reaching similar and higher values compared to IP of other seeds. The gel formation in neutral pH and salt absence require concentrations of 8 and 10% to PI 10.0 and PI 11.5, respectively. The highest foam formation was observed for PI 10.0 in neutral and alkaline pH, and it showed a capacity of up to 90% of the initial volume; however for the foam stability both IPs showed good properties of up to two hours after foam formation.
Protein isolates (PIs) were obtained from the guava seed flour (Psidium guajava) by extracting different pHs followed by isoelectric precipitation (pH 4.5). The conditions for preparation of the PIs were defined from the solubility curve at pH 10.0 and 11.5, in the absence of NaCl and a temperature of 25 ± 3 ºC. These conditions obtained protein isolated (PI) with extraction yield of 45.19 and 66.23%, with protein content of 96.4 and 93.5% for PI 10.0 and 11.5, respectively. The water and oil absorption capacity of 1.05 ± 0.07 and 2.30 ± 0.01 mL.g-1 protein and 1.65 ± 0.07 and 1.70 ± 0.07 mL.g-1 protein, respectively; were obtained for PI 10.0 and PI 11.5. Differences among the PIs regarding the emulsion activity and stability were not observed, reaching similar and higher values compared to IP of other seeds. The gel formation in neutral pH and salt absence require concentrations of 8 and 10% to PI 10.0 and PI 11.5, respectively. The highest foam formation was observed for PI 10.0 in neutral and alkaline pH, and it showed a capacity of up to 90% of the initial volume; however for the foam stability both IPs showed good properties of up to two hours after foam formation.
Descrição
Palavras-chave
Psidium guajava, semente de goiaba, propriedades funcionais, isolado protéico (IP), Psidium guajava, guava seed, Functional properties, protein isolate (PI)
Como citar
Food Science and Technology (Campinas). Sociedade Brasileira de Ciência e Tecnologia de Alimentos, v. 27, p. 73-79, 2007.