Physicochemical and functional properties of cowpea protein isolates treated with temperature or high hydrostatic pressure

PEYRANO FELICITAS; SPERONI FRANCISCO; AVANZA M.V

INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2015 vol. 33 p. 38 - 46

1466-8564

The effect of thermal (TT, 70 and 90 ºC) and high hydrostatic pressure (HHPT, 200, 400 and 600 MPa) treatments on physicochemical and functional properties of cowpea protein isolates (CPI) extracted at pH 8.0 (A8) and pH 10.0 (A10) was analyzed. The pH of protein extraction affected some physicochemical properties (surface hydrophobicity (Ho) and denaturation temperature), without affecting the functional properties. Treatments led to the formation of soluble protein aggregates stabilized by disulfide bonds, especially with TT at 90 ºC. TT and HHPT shifted the wavelengths of maximum emission to red and to blue, respectively. All treatments increased the Ho and decreased the denaturation enthalpy change, indicating protein unfolding and denaturation. HHPT was more efficient than TT to enhance the gelation capacity and water holding capacity. Interestingly, treated and untreated CPIs exhibited high values of solubility (72-97%). TT and HHPT induced larger changes in the physicochemical and functional properties of A8 proteins as compared to A10. Remarkably, functional properties were improved from the less energetic treatments (70 ºC, 200 MPa). Industrial relevance: The comparison between treatments (one traditional and one corresponding to an emerging technology) gives information about the possibility of obtaining modified proteins for different functional purposes. The modified cowpea protein isolates may be used in beverages because of high solubility, in desserts because of gel formation capacity and/or as additives in other foodstuff because of improved water holding capacity. This knowledge would increase the added value of a local production currently marketed without processing.