The influence of high hydrostatic pressure on different properties of legume proteins with an emphasis on soy proteins; a comprehensive review

Thermal treatment is the primary method of food preservation and pasteurization; nevertheless, it impairs food quality. High hydrostatic pressure (HHP) could be complementary, or alternative to thermal processing. Compared with thermal treatment, HHP has no significant impact on thermo-sensitive and small molecules including flavor compounds, amino acids and vitamins. In this review article, the effects of HHP treatment on functional and intrinsic (protein solubility, free sulfhydryl content, surface hydrophobicity, and water holding capacity), colloidal (turbidity, zeta potential, particle size distribution, and surface pressure isotherms), emul-sifying (emulsifying activity and protein adsorption), rheological, spectroscopic (ultraviolet absorbance and fluorescence), and structural, as well as nutritional properties of legume proteins (LPs) are comprehensively reviewed. It not only mentions the measurement detail of each described technique but also explains the effect of HHP treatment on the structural properties, colloidal stability as well as spectroscopic properties of legume proteins. Since most articles regarding the effect of HHP on legume proteins are devoted to the soybean; hence, the coverage of this article is mostly related to the soy proteins. HHP might improve the protein unfolding and the exposure of its hydrophobic groups which subsequently may increase the emulsion activity index. However, it may principally decrease the emulsion stability index. The comprehensive review of the relevant studies confirms the appropriate potential of HHP compared to other methods of protein modification. This method not only improves the functional properties of the LPs, but also reduces their allergenicity and antigenicity.