Abstract: The objective of the present study was to determine the effect of antifreeze peptides from tilapia scale (TSAPP) on the specific volume, fermentation properties, water loss rate, starch gelatinization degree, texture properties, water distribution and mobility of frozen potato dough during freeze-thaw cycles and to elucidate the underlying mechanism of action. The addition of 1% TSAPP could increase the specific volume, shorten the fermentation time, augmented the starch gelatinization degree and reduce the water loss rate. Texture analysis showed that the hardness, chewiness and gumminess of potato steamed bread containing 1% TSAPP were decreased respectively by 29.96%, 26.99%, and 28.30% as compared with those of the control group. Analysis by nuclear magnetic resonance (NMR) showed that TSAPP affected the water status in potato dough by increasing tightly bound water and decreasing semi-bound water. TSAPP could also inhibit water loss and increase the water holding capacity of potato dough. In conclusion, antifreeze peptides could be used as a cryoprotective agent in frozen potato dough products.

Key words: frozen potato dough, potato steamed bread, antifreeze peptide, freeze-thaw cycles, quality protection