Title
Effects of High Pressure and Heat Treatments on Physicochemical and Gelation Properties of Rapeseed Protein Isolate
Author
Rong He, Hai-Yan He, Dongfang Chao, Xingrong Ju, Rotimi Aluko
Year
2014
Journal
Food Bioprocess Technol (2014) 7:1344–1353
Abstract
High pressure (HP, 200, 400, and 600 MPa)- and
heat (60, 80, and 100 °C)-induced gelation, aggregation, and
structural conformations of rapeseed protein isolate (RPI) were
characterized using gel permeation–size-exclusion chromatography, differential scanning calorimetry, and circular dichroism
(CD) techniques. HP treatments significantly (p<0.05) increased the content of soluble protein aggregates and surface
hydrophobicity of RPI. In contrast, heat treatments at 80 and
100 °C led to significant (p<0.05) decreases in the amount of
soluble protein aggregates. At pressure treatment of 200 MPa,
there was a significant (p<0.05) increase in free sulfhydryl
group content of RPI, whereas 400- and 600-MPa treatments
as well as temperature treatments (60–100 °C) caused significant decreases. Protein denaturation temperature was increased by about 6 °C by HP and heat treatments. The farUV CD spectra revealed increases in α-helix content of RPI
after HP treatments with 400 MPa producing the most increase. Near-UV data showed that HP and heat treatments of
RPI led to increasing interactions among the aromatic
amino acids (evidence of protein aggregation), and between
aromatic amino acids and the hydrophilic environment,
which indicates protein unfolding. Least gelation concentration of RPI was significantly (p<0.05) reduced by HP
and heat treatments, but HP-treated RPI produced gels with
better textural properties (hardness increased from ~7.7 to
81.1 N, while springiness increased from ~0.37 to 0.99).
Overall, pressure treatments (200–600 MPa) were better
than heat treatments (60–100 °C) to modify the structure
and improve gelation properties of RPI.
Instrument
FP-6300, J-815
Keywords
Rapeseed protein isolate, High pressure treatment, Heat treatment, Gelation, Differential scanning calorimetry, Circular dichroism