Propriedades funcionais de proteínas da clara do ovo de codorna

• Autor(a) principal: Santos, Daniela Oliveira dos
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2857
• topic: Biosseparação; Ovo de codorna; Propriedades funcionais; Quail egg; Bioseparation; Functional properties; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS

In this work, the functional characteristics of solubility, capacity of foam formation and gelation of the egg white proteins of quail egg were studied. Solubility data were evaluated in function of the stirring time of the proteic solution, the pH value and the salt concentration (NaCl), at 25 ºC. The foam and gelation properties were analyzed as a function of the protein concentration, the pH value and the salt concentration. The proteic content of the samples of the supernadant was quantified by spectrophotometry using the reaction calorimetric technique of Biureto for the solubility tests. The tests to determine the foam formation capacity were made in a glass column with air insufflated through a porous disk, located internally in the upper part of the column. The gel texture characteristics were measured using an Instron's universal testing system, and the amount of exudated water was determined by centrifugation. The solubility data were influenced (P<0.05) by stirring time, pH and saline concentration. The higher solubility value equal to 98.92 g/100 g of protein was obtained in the system containing 0.05 mol/L of NaCl, in a pH value of 10.0, and a stirring time of 1 hour. The protein concentration, pH value and saline concentration, had a significant impact (P<0.05) on the foam expansion, except the pH value on foam stability. The largest stability value, ± 41 %, was presented in the concentration of 2 % of egg white both in a pH value of 10.0 and 0.4 mol/L of NaCl, and in a pH value of 3.0 and 0.6 mol/L of NaCl. The largest value of the systems expansion was of 662.2 %, and was found in an egg white concentration of 1 % in pH 10.0 and 0.05 mol/L of NaCl. Since egg white is a complex system constituted of different proteins, the characteristics of gelation functionality resulted from the interactions of properties of several proteins constituents. The elasticity, gel compression force and water retention capacity of gel were affected in a different way by protein concentration, pH value and saline concentration. The pH value of 10.0 produced gels with the best texture, the largest compression force and elasticity, and, the smallest exudated water amount.