Purpose: To investigate the effects
of oligosaccharides on the functional properties of
wheat starch.
Methods: The blue value,
retrogradation and pasting properties of wheat starch
were determined. In addition, water activity (Aw),
melting enthalpy and melting temperature of wheat starch
paste were analyzed.
Results: Fructo-oligosaccharide
(FOS) and xylo-oligosaccharide (XOS) inhibited the
retrogradation of wheat starch. The peak viscosity of
wheat starch with oligosaccharides increased from 3238 ±
8 to 3822 ± 10 cP, with the highest peak obtained for
sucrose. The setback of wheat starch decreased (from
1158 ± 5 to 799 ± 6 cP), with the lowest setback for
FOS. Aw of control sample changed significantly (falling
from 0.978 ± 0.025 to 0.397 ± 0.013) when the drying
time was from 6 to 12 hours, while the Aw of the samples
to which different oligosaccharides were added only
showed slight decrease (from 0.98 ± 0.019 to 0.854 ±
0.022). During storage, the Aw of all starch pastes
decreased, and the Aw and melting enthalpy of the
samples containing FOS and XOS were significantly lower
than that of the control after 6 days storage at 4 and
30 °C.
Conclusion: A certain level of
oligosaccharides can improve the functional properties
of wheat starch paste and thus broaden its application
prospects in food and pharmaceutical industries.
Keywords: Melting enthalpy,
Oligosaccharides, Pasting properties, Water activity,
Wheat starch