Abstract:

The objective of the study was to explore the effect and mechanism of action of heating temperature and addition
of flaxseed gum (FG) on water-holding capacity (WHC), gel strength, rheological properties, secondary structure and
3-dimensional network structure of heat-induced gels of pork myofibrillar protein (MP). The results revealed that increasing
temperature could significantly decrease gel WHC (P < 0.05), and increase gel strength (P < 0.05). The addition of FG
significantly enhanced WHC and decreased gel strength at temperature higher than 50 ℃ (P < 0.05). Raman spectroscopic
analysis revealed that increasing the temperature from 30 to 80 ℃ induced partial transformation of α-helices into β-sheets.
At the same heating temperature, the addition of FG led to the transformation of α-helices into β-sheets, thus affecting the
formation of gels. The rheological tests showed that storage modulus (G’) values during MP gelation were declined with
addition of FG (P < 0.05) when temperature was higher than 50 ℃. Gel holes of MP appeared at 50 ℃, and MP-FG formed
a fine dense network at both 70 and 80 ℃ as shown by scanning electron microscopy images.

Key words: temperature, myofibrillar protein, flaxseed gum, secondary structure, gel properties, gelling mechanism