Abstract:

Functional properties of tomato seed protein isolate (TSPI) prepared by alkali extraction and acid precipitation
are not as good as desired. The effect of high-pressure microfluidization treatment on functional properties and structure of
TSPI was studied. The results indicated that the changes in functional properties of TSPI might be related to the changes in
its structure. The solubility and emulsifying ability of TSPI were improved after microfluidization treatment; the diameter
of protein particles became smaller and the particle size distribution became more uniform; the exposed sulfhydryl and total
sulfhydryl contents were decreased; some intramolecular hydrophobic groups were exposed and the surface hydrophobicity
was improved; the changes of crystal structure were small; the secondary structures of TSPI were changed, that is, the
contents of α-helix, random coil and β-turn were decreased while the content of β-sheet was increased. These changes
revealed that the protein molecules were spread or folded after microfluidization treatment and thus the functional properties
were changed.

Key words: tomato seed protein isolate, microfluidization treatment, functional properties, structure