Preparation of protein and flavour stock solutions
2% (w/v) CPIs and PPIs solutions were prepared in 0.01 M potassium
phosphate buffer (pH 8) and subsequently placed into an
ultrasonic water bath (Branson 3200, Bransonic Ultrasonic Cleaner,
Shelton, CT) for 20 min to ensure a complete dispersion of the protein
isolates. The ionic strength was kept as low as possible to minimise
the effect of salt on protein conformation.
Stock solutions of each volatile flavour compound were prepared
in phosphate buffer solution at 1000 ppm (0.1 mL/100 mL)
and stored in amber glass bottles to prevent decomposition. Flavour
stock solutions were put in an ultrasonic water bath for 1 h
to ensure a thorough mixing before each use.