β-lactoglobulin (β-1g), a globular protein considered small, has each monomer with 162 amino
acids. Usually, at neutral pH and ambient temperature, it is in the form of dimers, native form
- where each subunit has the molecular weight of approximately 18.3 kDa. In addition to
temperature, the pH value and the calcium content are well known factors that influence the
denaturation and aggregation of the whey protein. In this context, the present work aimed to
study the changes in β-lactoglobulin (β-lg) structure caused by heating in the presence of
calcium ions (Ca) in acid medium. Based on the conditions established during the experiments,
it was possible to verify, through the Laser Diffraction (LD) granulometry, that the pH change
and the heating modifies the particle size of the studied solutions. In the investigation by nuclear
magnetic resonance (NMR) it was observed in low pHs the aggregation is smaller due to the
temperatures used, so the phenomenon that stands out most is denaturation, especially in the
samples in which they were previously heated.
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