Abstract:

In order to develop healthy meat products with low fat and high fiber and to clearly define the effect of dietary
fiber on the quality of meat products, we investigate properties of heat-induced gels of pork myofibrillar protein (MP) as
well as examined the influence of adding wheat bran dietary fibers to heat-induced MP gels on their properties using the
one-factor-at-a-time method. The results showed that the denaturation temperature of MP ranged from 40 to 70 ℃. With
the increase in protein concentration, the water-holding capacity (WHC) and gel hardness increased to reach a plateau at
70 mg/mL. At pH 5.5, the heat-induced gel showed the maximum hardness, and WHC tended to be stable at pH 7.0. Both gel
hardness and WHC showed a stable trend at the ionic strength of 0.6 mol/L. Meanwhile, the emulsifying capacity of MP was
increased but not significantly with increasing addition of wheat bran dietary fibers, showing an increase of 7.4% at an added
concentration of 5%, whereas emulsion stability decreased. Moreover, the elastic modulus, hardness and WHC of heatinduced
MP gels were enhanced. The gel hardness and WHC reached a plateau with the addition of 4% of wheat bran dietary
fibers. Gel microstructure became more loose with enlarged pore size as observed under scanning electron microscope (SEM).
By adding dietary fibers with smaller particle size, the WHC and hardness of gels became stronger, microscopic structure
became more compact, a the value of elastic modulus became smaller. In conclusion, dietary fiber can obviously change
the functional properties of myofibrillar proteins. The addition of the right amount of dietary fiber in meat products can
significantly improve meat flavor as a substitute for fat to reduce energy intake.

Key words: myofibrillar protein, wheat bran dietary fiber, functional properties, gel property