Inhibitory effects of β-ionone on amyloid fibril formation of β-lactoglobulin.

β-Lactoglobulin (β-LG) is the major constituent of whey food, which has been shown to interact with a wide range of aroma compounds. In the present work, a model aroma compound, β-ionone, is used to investigate the influence of aroma compounds on the urea-induced unfolding of β-LG at pH 7.0. β-Ionone is observed to enhance the stability of β-LG at pH 7.0. Moreover, the amyloid fibrils are observed when β-LG at pH 7.0 is incubated for 12-20 days at 37 °C in the presence of 3-5M urea. However, the formation of amyloid fibrils is inhibited when β-ionone is added into the samples and the inhibitory effects follow a concentration-dependent fashion. There is a clear correlation between Cm and lag time. The correlation demonstrates that protein stability affects the amyloid fibril formation of β-LG. The results highlight the critical role of protein stability and provide an approach to prevent the formation of amyloid fibrils in vitro.