Abstract: Ice structuring proteins (AISPs) were extracted from “Zhaodong” alfalfa hay into phosphate-buffered solution (PBS) followed by addition of ice spheres to bind AISPs, and their?anti-freeze activity?and?molecular?mass were determined.?Then AISPs were added into wheat flour before making dumpling wrappers and quick frozen dumplings. After several freeze-thaw cycles, the water-holding capacity of raw dumpling wrappers and the texture properties of raw and cooked dumpling wrappers were determined. The results showed that the relative molecular mass of AISPs was about 52 kDa and the thermal hysteresis activity was 0.54 ℃. The water-holding capacity of dumpling wrappers with added AISPs increased significantly with increasing number of freeze-thaw cycles. Both raw and cooked dumpling wrappers were kept homogeneous and stable and their textural properties were significantly improved with the addition of AISPs. Quick frozen dumpling wrappers with added AISPs showed no significant cracking. The scanning electron microscopic (SEM) characterization of quickly-frozen dumpling wrappers displayed that the surface structure of gluten network and starch granules were improved with the addition of AISPs, suggesting that AISPs can act as a cryoprotectant to improve the texture properties of quick frozen dumpling wrappers.

Key words: ice structuring protein, dumpling wrapper, water-holding capacity, texture characteristics, freeze-thaw cycle