A influencia de ions calcio nas caracteristicas de solubilidade, textura e capacidade de retenção de agua de geis de concentrados e isolado proteicos de soro de leite

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

Whey protein concentrates (80% protein) and whey protein isolate (90% protein) manufactured by ultrafiltration and diafiltration were evaluated for their solubility properties, textural characteristics and electrophoretic pattem. Concentrates and isolate tested in this study showed high solubility at pHs 7,0 and 4,6 (solubility higher than 84%). Protein solubility in systems prepared with 10% protein at pH 7,0, dialysed and non-dialysed, with the addition of different concentrations of CaCb ( O, 10, 15, 25 and 35 mM) showed a small decrease when 35 mM CaCI2was added, indicating the formation of few aggregates, confirmed by the transmittance pattems of the solutions. Gels obtained from these solutions was evaluated for hardness, adhesiveness, elasticity, cohesiveness, gumminess, chewiness and water retention capacity. These parameters were Ca2+and other ions dependent , mainly of anions present in the samples. Whey protein concentrates with the same total Ca2+ concentration showed different texture profile.The highest values for hardness were obtained with specific concentrations of calcium. Dialysed solutions were more sensitive to CaCb addition showing higher values for hardness, chewiness, gumminess, elasticity and cohesiveness. The maximum hardness value for the WPC Calpro 80 was obtained at 25 mM CaCb (613,02 g); sample AMP 80 showed maximum hardness when 15 mM CaCb were added to a dialysed system (627,95 g); maximum hardness for the WPI was obtained at 10 mM CaCb when the salt was added to the dialysed system (1050,12 g). Solutions with low ionic strength produced elastic g els, more coesive and with higher water retention capacity. Ca2+addition produced less elastic gels and with lower coesivity. The maximum water retention capacity for the three samples was obtained in the dialysed system without CaCb addition. The electrophoretic pattem indicated that with the addition of 25 and 35 mM CaCb the gels structures were mantained by electrostatic interactions, while at the addition levels of O, 15 e 15 mM of CaCI2 the structure was supported by disulphide and electrostatic interactions and the proteins involved in the process of aggregates formation through interactions S-S were a-Iactalbumin and (3-lactoglobulin

ASSUNTO(S)

eletroforese solubilidade soro do leite calcio

ACESSO AO ARTIGO

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