Impact of temperature on aggregation and gelation of potato protein under salt condition typical for food systems.

The European Farm-to-Fork strategy partially focuses on a shift towards alternative protein. Among these, potato protein is promising, because it is nutritious, low allergenic and highly techno-functional. However, research on the impact of temperature on potato protein gel properties under salt conditions typical for food systems is lacking. Therefore, the effect of temperature (50 °C, 60 °C, 70 °C or 90 °C, selected based on differential scanning calorimetry) of isothermal treatment on potato protein aggregation and gelation was studied in a model system containing 250 mM NaCl. Two new analyses in potato protein research, residual denaturation enthalpy and SDS-PAGE of soluble protein, revealed denaturation and aggregation of patatin between 50 and 60 °C and of protease inhibitors between 60 and 70 °C. The aggregation mechanism relies on hydrophobic interactions and/or hydrogen bonds, both for patatin and protease inhibitors. The temperature regimes could be linked to a decrease in least gelation concentration and to an increase in water holding capacity, stiffness, fracture stress and fracture strain of potato protein gels.