Functional properties of cross-linked and hydroxypropylated waxy hull-lessbarley starches

Waxy hull-less barley (HB) starches containing 0 or 5% amylose were cross-l inked with phosphorus oxychloride and the cross-linked starches were hydrox ypropylated with propylene oxide. For comparison, waxy corn and potato star ches were similarly modified. For all starches, cross-linking inhibited gra nule swelling and prevented swollen granules from disintegration, resulting in dramatic improvement in pasting properties and tolerance to cooking she ar and autoclaving. Cross-linked waxy HE starches were more tolerant to col d storage and cooking shear than cross-linked waxy corn starch. Hydroxyprop ylation of the cross-linked starches reduced granule crystallinity and gela tinization temperature, and improved granule swelling, paste clarity, and f reeze-thaw stability. The double-modified wavy HE starches showed higher co ld tolerance than similarly modified waxy corn and potato starches, as judg ed by freeze-thaw stability and clarity after cold storage. These results i ndicated that the cross-linked and double-modified waxy HE starches togethe r may have a wide range of food applications. This study indicated that the behavior of granule swelling and disintegration of swollen granules played an important role in governing paste viscosity, clarity and freeze-thaw st ability of wavy HE starches.