ABSTRACT
Similarly to heating, non-thermal technologies like High Hydrostatic Pressure (HHP) are able to
affect the native conformation of proteins, causing denaturation, aggregation or gelation. The aim
of this work is to evaluate the effect of product’s chemical-physical characteristics, namely pH and
protein concentration, and process parameters, namely pressure level and processing time, on the
stability of the structure of a particular allergen, the Bovine Serum Albumin (BSA) as well as to individuate
the most appropriate processing conditions to induce protein denaturation and/or aggregation.
Different amounts of BSA protein were dissolved in phosphate buffer (50 mM) at three
different pH (6, 7 and 8), to obtain concentration levels of 12, 25, 50 and 100 mg/mL. The HHP
process was carried out at pressure levels in the range between 700 and 900 MPa and treatment
time of 15 - 25 min. The structural characteristics of HHP-treated BSA suspensions were assessed
by means of a complete rheological screening (strain sweep, frequency sweep and temperature
ramp tests) in dynamic regime. Experimental data demonstrate that the rheological parameters,
namely the loss and the storage moduli, increase as pressure levels and processing time increase,
especially at higher concentrations, whereas a constant critical strain of about 0.3% is detected.
The pH and protein concentration mainly control the denaturation influencing the threshold value
of the processing conditions at which the gelation occurs. At processing conditions below the
threshold values, however, the structure of BSA can be reversibly damaged.