Abstract: This study investigated the functional properties of blends of normal barley starch (NBS) and waxy barley starch (WBS) with different mass ratios (75:25, 50:50 and 25:75) in excess water (water content 95%, m/m) such as solubility, swelling power, water absorption capacity, pasting properties, gel strength, and freeze-thaw stability. The results showed that with increasing amount of WBS, the solubility and puncture force of the blends significantly fell (P < 0.05), whilst the swelling power and water absorption capacity reached the maximum at WBS50. The pasting curves measured by a rapid viscosity analyzer showed that with increasing amount of WBS, the peak viscosity significantly increased (P < 0.05). Meanwhile, NBS75:WBS25 possessed the highest pasting temperature (P < 0.05). Furthermore, with increasing amount of WBS, the freeze-thaw stability of starch blends significantly improved after different freeze-thaw cycles (P < 0.05), which was verified by the results of electron microscopy scanning. Our present study indicated that changing the mass ratio of NBS to WBS had a significant effect on the functional properties of starch blends. This study provides a theoretical basis for the application of WBS and NBS blends in the food industry.

Key words: normal barley starch; waxy barley starch; starch blends; functional properties; freeze-thaw stability