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The objective of this study is to elucidate the effect of
single or combined physical treatments on the physical property
changes of the concentration soy 11S globulin solution. The
physical treatments include heating, shearing and ultrasonic
radiation whereas the physical properties interested are surface
hydrophobicity, average particle size , secondary structure and
dynamic properties. The concentration of soy 11S globulin
solution is 10％soy 11S globulin dispersion in phosphate buffer
pH 7.6, μ﹦0.5. The results show surface hydrophobicity,
average particle size of soy 11S globulin increased with
increased heating temperature and heating time. α－helix
content increased from 11％ for unheated to 24, 25 and 29％ for
those heated at 70, 80 and 90℃for 30 min, respectively. Loss
tangent angle, one of the dynamic properties, decreased with
increasing heating temperature and heating time. Shear treatment
resulted in increasing surface hydrophobicity, and increasing
average particle size of soy 11S globulin in concentration
solution. The increase was proportional to the increase of shear
rate and shear time. The proportion of orderly secondary
structureα－helix andβ－sheet increased with increasing shear
rate and treatment time. Loss tangent angle decreased with
increasing shear rate and shearing time. Ultrasonic radiation
treatment resulted in increased surface hydrophobicity of soy
11S globulin in concentrated solution. The increase was
proportional to the power and duration of ultrasonic radiation.
Average particle size of soy 11S globulin in concentrated
solution decreased after ultrasonic treatment at 180 Watt or 300
Watt for 5 min, however average particle size increased after
ultrasonic at 420 Watt for 5 min. Orderly secondary structure of
α－helix orβ－sheet of soy 11S globulin increased with
increasing power and duration of ultrasonic treatment. However
loss tangent angle decreased in proportion to the increase of
power and duration of ultrasonic treatment. Combined heating and
shearing treatment on concentrated soy 11S globulin solution
resulted in increasing its surface hydrophobicity and average
particle size. The increase were proportional to the heating
temperature and shear rate employed . The magnitude of increase
in surface hydrophobicity of soy 11S globulin subjected to
difference treatments were in order of shear treatment alone
larger than combined heating and shearing in turn larger than
heating treatment alone. The order of increasing in average
particle size were in order of heating alone for 60 min higher
than combined shear and heating for 5 min in turn larger than
shear alone for 10 min. Orderly secondary structure increased
after combined heating and shearing. The increase were higher
for those subjected to higher temperature and higher shear rate
treatment. The loss tangent angle decreased with increasing
shear rate and heat temperature employed. Combined heating and
ultrasonic radiation treatment resulted in increasing surface
hydrophobicity and average particle size of treated soy 11S
globulin in concentrate solution. The increase was proportional
to the increase in temperature and ultrasonic radiation power.
Increase in surface hydrophobicity resulted from combined
heating and ultrasonic radiation was almost equal to ultrasonic
treatment alone but higher that or than heat treatment alone.
Increase in average particle size resulted from treatments were
in order of heating alone for 60 min larger than combined
heating and ultrasonic for 10 min in turn larger than ultrasonic
treatment alone for 10 min. Increase in orderly secondary
structure α－helix andβ－sheet were proportional to heating
temperature and ultrasonic radiation power used. The higher the
temperature and the higher the power of ultrasonic radiation,
the higher proportion of orderly secondary structure in soy 11S
globulin resulted so as the decease in loss tangent angle after
combined treatment.
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